] Ezetimibe and Simvastatin Tablets Drug Interactions Associated With Increased Risk of Myopathy/Rhabdomyolysis ( 2.3 , 2.4 , 4 , 5.1 , 7.1 , 7.2 , 7.3 , 7.8 , 12.3 ) Interacting Agents Prescribing Recommendations Strong CYP3A4 Inhibitors, (e.g., itraconazole, ketoconazole, posaconazole, voriconazole, erythromycin, clarithromycin, telithromycin, HIV protease inhibitors, boceprevir, telaprevir, nefazodone, cobicistat-containing products), gemfibrozil, cyclosporine, danazol Contraindicated with ezetimibe and simvastatin tablets Niacin (≥1 g/day) For Chinese patients, not recommended with ezetimibe and simvastatin tablets Verapamil, diltiazem, dronedarone Do not exceed 10 mg/10 mg ezetimibe and simvastatin tablets, daily Amiodarone, amlodipine, ranolazine Do not exceed 10 mg/20 mg ezetimibe and simvastatin tablets, daily Lomitapide For patients with HoFH, do not exceed 10 mg/20 mg ezetimibe and simvastatin tablets 1 Daptomycin Temporally suspend ezetimibe and simvastatin tablets Grapefruit juice Avoid grapefruit juice 1. If treatment with itraconazole, ketoconazole, posaconazole, voriconazole, erythromycin, clarithromycin or telithromycin is unavoidable, therapy with ezetimibe and simvastatin tablets must be suspended during the course of treatment.
Source: FDA drug label - ezetimibe and simvastatin
( 7.2 ) 7.1 Effects of Other Drugs on Ranolazine Strong CYP3A Inhibitors Do not use ranolazine with strong CYP3A inhibitors, including ketoconazole, itraconazole, clarithromycin, nefazodone, nelfinavir, ritonavir, indinavir, and saquinavir [see Contraindications (4) , Clinical Pharmacology (12.3) ].
Source: FDA drug label - ranolazine
Telaprevir Decrease AUC by 92% Systemic Hormonal Contraceptives Prevention or Management: Advise patients to change to non-hormonal methods of birth control during rifampin therapy Estrogens Decrease exposure Progestins Anticonvulsants Phenytoin Administered with rifampin 450 mg daily Decrease exposure Antiarrhythmics Disopyramide Decrease exposure Mexiletine Decrease exposure Quinidine Decrease exposure Propafenone Decrease AUC by 50%–67% Tocainide Decrease exposure Antiestrogens Tamoxifen Decrease AUC by 86% Toremifene Decrease steady state concentrations of toremifene in serum Antithrombotic Agents Clopidogrel Prevention or Management: Concomitant use of clopidogrel and rifampin should be discouraged Increase active metabolite exposure and risk of bleeding Ticagrelor Prevention or Management: Avoid use Decrease exposure Antipsychotics Haloperidol Decrease plasma concentrations by 70% Lurasidone Prevention or Management : Concomitant use is contraindicated (See CONTRAINDICATIONS ) Decrease exposure Oral Anticoagulants Prevention or Management: Perform prothrombin time daily or as frequently as necessary to establish and maintain the required dose of anticoagulant Warfarin Decrease exposure Antifungals Fluconazole Decrease AUC by 23% Itraconazole Prevention or Management: Not recommended 2 weeks before and during itraconazole treatment Decrease exposure Ketoconazole Decrease exposure Caspofungin Prevention or Management: Refer to the caspofungin prescribing information for caspofungin dose adjustment.
Source: FDA drug label - rifampin
7 DRUG INTERACTIONS Sildenafil citrate can potentiate the hypotensive effects of nitrates, alpha blockers, and anti-hypertensives ( 4.1 , 5.5 , 7.1 , 7.2 , 7.3 , 12.2 ) With concomitant use of alpha blockers, initiate sildenafil citrate at 25 mg dose ( 2.3 ) CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin): Increase sildenafil citrate exposure ( 2.4 , 7.4 , 12.3 ) Ritonavir: Do not exceed a maximum single dose of 25 mg in a 48 hour period ( 2.4 , 5.6 ) Erythromycin or strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, saquinavir): Consider a starting dose of 25 mg ( 2.4 , 7.4 ) 7.1 Nitrates Administration of sildenafil tablets with nitric oxide donors such as organic nitrates or organic nitrites in any form is contraindicated. Stronger CYP3A4 inhibitors such as ketoconazole or itraconazole could be expected to have greater effects than seen with saquinavir. A starting dose of 25 mg of sildenafil tablets should be considered in patients taking erythromycin or strong CYP3A4 inhibitors (such as saquinavir, ketoconazole, itraconazole) [ see Dosage and Administration ( 2.4 ), Clinical Pharmacology ( 12.3 ) ] .
Source: FDA drug label - sildenafil
7 DRUG INTERACTIONS Sildenafil can potentiate the hypotensive effects of nitrates, alpha blockers, and anti-hypertensives ( 4.1 , 5.5 , 7.1 , 7.2 , 7.3 , 12.2 ) With concomitant use of alpha blockers, initiate sildenafil at 25 mg dose ( 2.3 ) CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin): Increase sildenafil exposure ( 2.4 , 7.4 , 12.3 ) Ritonavir: Do not exceed a maximum single dose of 25 mg in a 48 hour period ( 2.4 , 5.6 ) Erythromycin or strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, saquinavir): Consider a starting dose of 25 mg ( 2.4 , 7.4 ) 7.1 Nitrates Administration of sildenafil with nitric oxide donors such as organic nitrates or organic nitrites in any form is contraindicated. Stronger CYP3A4 inhibitors such as ketoconazole or itraconazole could be expected to have greater effects than seen with saquinavir. A starting dose of 25 mg of sildenafil should be considered in patients taking erythromycin or strong CYP3A4 inhibitors (such as saquinavir, ketoconazole, itraconazole) [ see Dosage and Administration (2.4) , Clinical Pharmacology (12.3) ].
Source: FDA drug label - sildenafil citrate
In vivo studies Do not use vardenafil orally disintegrating tablet with moderate and strong CYP3A4 inhibitors such as erythromycin, grapefruit juice, clarithromycin, ketoconazole, itraconazole, indinavir, saquinavir, atazanavir, ritonavir as the systemic concentration of vardenafil is increased in their presence [see Warnings and Precautions (5) and Dosage and Administration ( 2.4 )] . Strong CYP3A4 inhibitors Ketoconazole (200 mg once daily) produced a 10-fold increase in vardenafil area under the curve (AUC) and a 4-fold increase in maximum concentration (C max ) when co-administered with vardenafil 5 mg in healthy volunteers.
Source: FDA drug label - vardenafil
Intervention Avoid concomitant use of FOCINVEZ Examples Moderate inhibitor: diltiazem Strong inhibitors: ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, nelfinavir Strong CYP3A4 Inducers Clinical Impact Substantially decreased exposure of aprepitant in patients chronically taking a strong CYP3A4 inducer may decrease the efficacy of FOCINVEZ [see Clinical Pharmacology (12.3)] .
Source: FDA drug label - fosaprepitant dimeglumine
Ketoconazole (Potent Inhibitor of CYP3A4) Coadministration of a single 500 mg oral dose of mefloquine with 400 mg of ketoconazole once daily for 10 days in 8 healthy volunteers resulted in an increase in the mean C max and AUC of mefloquine by 64% and 79%, respectively, and an increase in the mean elimination half-life of mefloquine from 322 hours to 448 hours. Ketoconazole should not be administered with mefloquine or within 15 weeks of the last dose of mefloquine due to the risk of a potentially fatal prolongation of the QTc interval (see WARNINGS ).
Source: FDA drug label - mefloquine hydrochloride
7.2 Strong Inducers and Strong Inhibitors of CYP3A4 and P-gp Avoid concomitant use of sirolimus with strong inducers (e.g., rifampin, rifabutin) and strong inhibitors (e.g., ketoconazole, voriconazole, itraconazole, erythromycin, telithromycin, clarithromycin) of CYP3A4 and P-gp.
Source: FDA drug label - sirolimus
7.2 Drugs that Inhibit Cytochrome P450 3A Enzymes and Drug Transport Systems Interaction with Combined P-gp and Strong CYP3A Inhibitors Avoid concomitant administration of XARELTO with known combined P-gp and strong CYP3A inhibitors (e.g., ketoconazole and ritonavir) [see Warnings and Precautions (5.6) and Clinical Pharmacology (12.3) ] .
Source: FDA drug label - rivaroxaban
Increase tacrolimus dose and monitor tacrolimus whole blood trough concentrations [see Dosage and Administration ( 2.2 , 2.6 ) and Clinical Pharmacology (12.3 ) ] Strong CYP3A Inhibitors : Protease inhibitors (e.g, nelfinavir, telaprevir, boceprevir, ritonavir), azole antifungals (e.g., voriconazole, posaconazole, itraconazole, ketoconazole), antibiotics (e.g., clarithromycin, troleandomycin, chloramphenicol), nefazodone,letermovir, Schisandra sphenanthera extracts May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation).A rapid, sharp rise in tacrolimus levels may occur early, despite an immediate reduction of tacrolimus dose [see Warnings and Precautions ( 5.6 , 5.11 , 5.12 )] Reduce tacrolimus dose (for voriconazole and posaconazole, give one-third of the original dose) and adjust dose based on tacrolimus whole blood trough concentrations [see Dosage and Administration ( 2.2 , 2.6 ) and Clinical Phamacology ( 12.3 )].
Source: FDA drug label - tacrolimus
Strong CYP3A Inhibitors : Protease inhibitors (e.g., nelfinavir, telaprevir, boceprevir, ritonavir), azole antifungals (e.g., voriconazole, posaconazole, itraconazole, ketoconazole), antibiotics (e.g., clarithromycin, troleandomycin, chloramphenicol), nefazodone, letermovir, Schisandra sphenanthera extracts May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation).
Source: FDA drug label - tacrolimus extended-release capsules
Avoid use of strong inhibitors of CYP3A (e.g., ketoconazole, itraconazole, voriconazole, clarithromycin, nefazodone, ritonavir, saquinavir, nelfinavir, indinavir, atazanavir and telithromycin) [see Clinical Pharmacology ( 12.3 )] .
Source: FDA drug label - ticagrelor
Examples Ketoconazole, itraconazole, clarithromycin Moderate or Weak Inhibitors of CYP3A Clinical implication Concomitant use of alprazolam with CYP3A inhibitors may increase the concentrations of alprazolam, resulting in increased risk of adverse reactions of alprazolam [see Clinical Pharmacology (12.3) ].
Source: FDA drug label - alprazolam
( 5.6 , 7.2 ) Other potent CYP3A4 inhibitors, such as ketoconazole: use caution with coadministration. Ketoconazole (also a strong CYP3A4 inhibitor), administered in multiple 200 mg doses to steady-state, increased plasma exposure of fluticasone propionate, reduced plasma cortisol AUC, but had no effect on urinary excretion of cortisol, following administration of a single 1,000 mcg dose of fluticasone propionate by oral inhalation route. Caution should be exercised when azelastine hydrochloride and fluticasone propionate nasal spray is coadministered with ketoconazole and other known strong CYP3A4 inhibitors.
Source: FDA drug label - azelastine hydrochloride and fluticasone propionate
Ketoconazole Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - betamethasone sodium phosphate and betamethasone acetate
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally administered budesonide increased. Caution should be exercised when considering the co-administration of PULMICORT FLEXHALER with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) [see Warnings and Precautions (5.7) ] .
Source: FDA drug label - budesonide
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally administered budesonide increased. Caution should be exercised when considering the coadministration of budesonide and formoterol fumarate dihydrate with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) [see Warnings and Precautions (5.9) ] .
Source: FDA drug label - budesonide and formoterol fumarate dihydrate
Reduce cilostazol tablets dose ( 2.2 , 7.1 ) 7.1 Inhibitors of CYP3A4 or CYP2C19 Inhibitors of CYP3A4 Coadministration of strong (e.g., ketoconazole) and moderate (e.g., erythromycin, diltiazem and grapefruit juice) CYP3A4 inhibitors can increase exposure to cilostazol.
Source: FDA drug label - cilostazol
In patients with moderate renal impairment (CrCl 30 to 50 mL/min), reduce the dosage of dabigatran etexilate to 75 mg twice daily when administered concomitantly with the P-gp inhibitors dronedarone or systemic ketoconazole. 7.3 Prophylaxis of Deep Vein Thrombosis and Pulmonary Embolism in Adult Patients Following Hip Replacement Surgery In patients with CrCl ≥50 mL/min who have concomitant administration of P-gp inhibitors such as dronedarone or systemic ketoconazole, it may be helpful to separate the timing of administration of dabigatran and the P-gp inhibitor by several hours.
Source: FDA drug label - dabigatran etexilate
Other: trazodone ↑ trazodone Antifungals: itraconazole, isavuconazole, ketoconazole, posaconazole ↑ darunavir ↑ itraconazole ↑ isavuconazole ↑ ketoconazole ↔ posaconazole Monitor for increased darunavir/ritonavir and/or antifungal adverse events with concomitant use of these antifungals. When co-administration is required, the daily dose of ketoconazole or itraconazole should not exceed 200 mg with monitoring for increased antifungal adverse events.
Source: FDA drug label - darunavir
amitriptyline, desipramine, imipramine, nortriptyline ↑ TCAs Other antidepressants: trazodone ↑ trazodone Antifungals: itraconazole, isavuconazole, ketoconazole, posaconazole ↑ darunavir ↑ cobicistat Monitor for increased darunavir or cobicistat and/or antifungal adverse reactions. ↑ itraconazole ↑ ketoconazole ↑ isavuconazole ↔ posaconazole Specific dosing recommendations are not available for co-administration with these antifungals. Monitor for increased itraconazole or ketoconazole adverse reactions.
Source: FDA drug label - darunavir ethanolate and cobicistat
Drugs which inhibit CYP 3A4 (e.g., ketoconazole, macrolide antibiotics such as erythromycin) have the potential to result in increased plasma concentrations of corticosteroids. Ketoconazole: Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to increased risk of corticosteroid side effects. In addition, ketoconazole alone can inhibit adrenal corticosteroid synthesis and may cause adrenal insufficiency during corticosteroid withdrawal.
Source: FDA drug label - dexamethasone
Concomitant administration of moderate or strong CYP3A4 inhibitors such as azole antifungals (e.g., ketoconazole, itraconazole, voriconazole, fluconazole), verapamil, macrolides (e.g., clarithromycin, erythromycin), diltiazem, and grapefruit juice can increase the plasma concentrations of the estrogen or the progestin or both. In a clinical drug-drug interaction study conducted in premenopausal women, once daily co-administration of DRSP 3 mg/EE 0.02 mg containing tablets with strong CYP3A4 inhibitor, ketoconazole 200 mg twice daily for 10 days resulted in a moderate increase of DRSP systemic exposure. In a clinical drug-drug interaction study conducted in 20 premenopausal women, co-administration of a DRSP (3 mg)/EE (0.02 mg) COC with the strong CYP3A4 inhibitor ketoconazole (200 mg twice daily) for 10 days increased the AUC(0-24h) of DRSP and EE by 2.68-fold (90% CI: 2.44, 2.95) and 1.40-fold (90% CI: 1.31, 1.49), respectively.
Source: FDA drug label - drospirenone and ethinyl estradiol
Concomitant administration of strong or moderate CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma estrogen and/or progestin concentrations.
Source: FDA drug label - etonogestrel and ethinyl estradiol vaginal ring
7 DRUG INTERACTIONS Systemic Ketoconazole: Monitor during concomitant use. 7.2 Ketoconazole The blood levels of fingolimod and fingolimod-phosphate are increased by 1.7-fold when used concomitantly with ketoconazole. Patients who use fingolimod and systemic ketoconazole concomitantly should be closely monitored, as the risk of adverse reactions is greater.
Source: FDA drug label - fingolimod
7 DRUG INTERACTIONS • Systemic Ketoconazole: Monitor during concomitant use. 7.2 Ketoconazole The blood levels of fingolimod and fingolimod-phosphate are increased by 1.7-fold when used concomitantly with ketoconazole. Patients who use fingolimod and systemic ketoconazole concomitantly should be closely monitored, as the risk of adverse reactions is increased.
Source: FDA drug label - fingolimod hydrochloride
Table 14: Clinically Important Drug Interactions: Effect of other Drugs on Guanfacine Extended-Release Tablets Concomitant Drug Name or Drug Class Clinical Rationale and Magnitude of Drug Interaction Clinical Recommendation Strong and moderate CYP3A4 inhibitors, e.g., ketoconazole, fluconazole Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in an increase in exposure Consider dose reduction [see Dosage and administration (2.7) ] Strong and moderate CYP3A4 inducers, e.g., rifampin, efavirenz Guanfacine is primarily metabolized by CYP3A4 and its plasma concentrations can be significantly affected resulting in a decrease in exposure Consider dose increase [see Dosage and administration (2.7) ] Strong and moderate CYP3A4 inhibitors increase guanfacine exposure.
Source: FDA drug label - guanfacine
Ketoconazole: Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroids side effects.
Source: FDA drug label - hydrocortisone acetate
7 DRUG INTERACTIONS Potential for other drugs to affect ivacaftor CYP3A inhibitors: Reduce KALYDECO dosage in patients aged 6 months and older when co-administered with strong CYP3A inhibitors (e.g., ketoconazole) or moderate CYP3A inhibitors (e.g., fluconazole). Co-administration with ketoconazole, a strong CYP3A inhibitor, significantly increased ivacaftor exposure [measured as area under the curve (AUC)] by 8.5-fold. Based on simulations of these results, a reduction of the KALYDECO dosage is recommended for patients aged 6 months and older taking concomitant strong CYP3A inhibitors, such as ketoconazole, itraconazole, posaconazole, voriconazole, telithromycin, and clarithromycin.
Source: FDA drug label - ivacaftor
Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - lidocaine hydrochloride, triamcinolone acetonide, povidone-iodine
Examples: Ketoconazole, clarithromycin, ritonavir, voriconazole, mibefradil Moderate CYP3A4 Inhibitors Clinical Impact: Concomitant use of lurasidone hydrochloride with moderate CYP3A4 inhibitors increased the exposure of lurasidone compared to the use of lurasidone hydrochloride alone [see Clinical Pharmacology ( 12.3 )].
Source: FDA drug label - lurasidone hydrochloride
Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - marcaine, kenalog, povidone iodine
Hepatic Enzyme Inhibitors (e.g., ketoconazole, macrolide antibiotics such as erythromycin and troleandomycin): Drugs which inhibit cytochrome P450 3A4 have the potential to result in increased plasma concentrations of corticosteroids. Ketoconazole: Ketoconazole has been reported to significantly decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - methylprednisolone acetate
Hepatic Enzyme Inhibitors (e.g., ketoconazole, macrolide antibiotics such as erythromycin and troleandomycin): Drugs which inhibit cytochrome P450 3A4 have the potential to result in increased plasma concentrations of corticosteroids. Ketoconazole : Ketoconazole has been reported to significantly decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - methylprednisolone acetate, lidocaine hydrochloride, bupivacaine hydrochloride, povidine iodine, sodium chloride, isopropyl alcohol
Hepatic Enzyme Inhibitors (e.g., ketoconazole, macrolide antibiotics such as erythromycin and troleandomycin) Drugs which inhibit cytochrome P450 3A4 have the potential to result in increased plasma concentrations of corticosteroids. Ketoconazole Ketoconazole has been reported to significantly decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - methylprednisolone sodium succinate
After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally inhaled mometasone furoate increased. Caution should be exercised when considering the coadministration of ASMANEX HFA with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, cobicistat-containing products, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin) [see Warnings and Precautions (5.6) and Clinical Pharmacology (12.3) ] .
Source: FDA drug label - mometasone furoate
Substances increasing the systemic concentrations of HCs: Co-administration of certain HCs and strong or moderate CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase the systemic concentrations of progestins, including norethindrone.
Source: FDA drug label - norethindrone
Caution should be exercised when paclitaxel is concomitantly administered with known substrates (e.g., midazolam, buspirone, felodipine, lovastatin, eletriptan, sildenafil, simvastatin, and triazolam), inhibitors (e.g., atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, ritonavir, saquinavir, and telithromycin), and inducers (e.g., rifampin and carbamazepine) of CYP3A4.
Source: FDA drug label - paclitaxel
Concomitant administration of a Moderate CYP 3A inducer, such as efavirenz, should be avoided unless the benefit outweighs the risks [see Warnings and Precautions (5.6) and Clinical Pharmacology (12.3) .] 7.2 CYP450 Inhibitors Concomitant administration of drugs that decrease the activity of drug metabolizing liver enzymes (CYP450 inhibitors), for example, cimetidine, ketoconazole, itraconazole, erythromycin, and ritonavir may increase plasma concentrations of praziquantel.
Source: FDA drug label - praziquantel
Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60% leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - prednisolone sodium phosphate
( 7.1 ) Ketoconazole (strong CYP3A4 inhibitor): Increases AUC for ramelteon; administer with caution. Ketoconazole (strong CYP3A4 inhibitor) The AUC 0-inf and C max of ramelteon increased by approximately 84% and 36% upon coadministration of ketoconazole with ramelteon. Ramelteon should be administered with caution in subjects taking strong CYP3A4 inhibitors such as ketoconazole [see Clinical Pharmacology (12.5) ] .
Source: FDA drug label - ramelteon
Agents for Opportunistic Infections Antifungals: Fluconazole Itraconazole Ketoconazole ↑ Tipranavir, ↔ Fluconazole Fluconazole increases tipranavir concentrations but dose adjustments are not needed. Voriconazole ↑ Itraconazole (not studied) ↑ Ketoconazole (not studied) Based on theoretical considerations itraconazole and ketoconazole should be used with caution.
Source: FDA drug label - tipranavir
Ketoconazole has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to an increased risk of corticosteroid side effects.
Source: FDA drug label - triamcinolone acetonide
In a dedicated drug interaction trial, co-administration of ketoconazole, a strong inhibitor of CYP3A4, had no clinically meaningful effect on the pharmacokinetics of abiraterone [see Clinical Pharmacology ( 12.3 )].
Source: FDA drug label - abiraterone acetate
Examples: Erythromycin, clarithromycin, itraconazole, ketoconazole, posaconazole, and voriconazole.
Source: FDA drug label - amlodipine and atorvastatin
However, strong inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, ritonavir) may increase the plasma concentrations of amlodipine to a greater extent.
Source: FDA drug label - amlodipine besylate
Azoles (e.g., ketoconazole, miconazole, clotrimazole, fluconazole, etc.) In vitro and in vivo animal studies of the combination of amphotericin B and imidazoles suggest that imidazoles may induce fungal resistance to amphotericin B.
Source: FDA drug label - amphotericin b
( 7.2 , 12.3 ) 7.1 Combined P-gp Strong CYP3A4 Inhibitors For patients receiving apixaban 5 mg or 10 mg twice daily, the dose of apixaban should be decreased by 50% when coadministered with drugs that are combined P-gp and strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) [see Dosage and Administration (2.5) and Clinical Pharmacology ( 12.3) ].
Source: FDA drug label - apixaban
Antifungals: ketoconazole, itraconazole REYATAZ with ritonavir: ↑ ketoconazole ↑ itraconazole Coadministration of ketoconazole has only been studied with REYATAZ without ritonavir (negligible increase in atazanavir AUC and C max ). Due to the effect of ritonavir on ketoconazole, high doses of ketoconazole and itraconazole (>200 mg/day) should be used cautiously when administering REYATAZ with ritonavir.
Source: FDA drug label - atazanavir
Examples: Erythromycin, clarithromycin, itraconazole, ketoconazole, posaconazole, and voriconazole.
Source: FDA drug label - atorvastatin calcium
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir) etc.
Source: FDA drug label - benzhydrocodone and acetaminophen
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inducers can decrease the plasma concentration of buprenorphine [see Clinical Pharmacology (12.3)] , potentially resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to buprenorphine.
Source: FDA drug label - buprenorphine
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of buprenorphine and CYP3A4 inducers can decrease the plasma concentration of buprenorphine [see Clinical Pharmacology (12.3) ] , potentially resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to buprenorphine.
Source: FDA drug label - buprenorphine and naloxone
ketoconazole), protease inhibitors (e.g., ritonavir).
Source: FDA drug label - buprenorphine hydrochloride
Other Inhibitors and Inducers of CYP3A4 Substances that inhibit CYP3A4, such as ketoconazole or ritonavir, may inhibit buspirone metabolism and increase plasma concentrations of buspirone while substances that induce CYP3A4, such as dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism.
Source: FDA drug label - buspirone
Other inhibitors and inducers of CYP3A4: Substances that inhibit CYP3A4, such as ketoconazole or ritonavir, may inhibit buspirone metabolism and increase plasma concentrations of buspirone while substances that induce CYP3A4, such as dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism.
Source: FDA drug label - buspirone hydrochloride
ketoconazole), protease inhibitors (e.g., ritonavir), grapefruit juice CYP3A4 Inducers Clinical Impact: The concomitant use of Butalbital, Acetaminophen, Caffeine, and Codeine Phosphate Capsules and CYP3A4 inducers can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels [see Clinical Pharmacology (12.3) ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence [see Warnings and Precautions (5.7) ] .
Source: FDA drug label - butalbital, acetaminophen, caffeine, and codeine phosphate
Drugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides (e.g., erythromycin, clarithromycin), fluoxetine, fluvoxamine, trazodone, omeprazole, oxybutynin, isoniazid, niacinamide (nicotinamide), azoles (e.g., ketaconazole, itraconazole, fluconazole, voriconazole), acetazolamide, verapamil, ticlopidine, grapefruit juice, and protease inhibitors.
Source: FDA drug label - carbamazepine
In a drug interaction study, co-administration of orally inhaled ciclesonide and oral ketoconazole, a potent inhibitor of cytochrome P450 3A4, increased the exposure (AUC) of des-ciclesonide by approximately 3.6-fold at steady state, while levels of ciclesonide remained unchanged.
Source: FDA drug label - ciclesonide
Alteration of pH may affect absorption of certain drugs (e.g., ketoconazole).
Source: FDA drug label - cimetidine
Dose adjustment of cinacalcet tablets may be required if a patient initiates or discontinues therapy with a strong CYP3A4 inhibitor (e.g., ketoconazole, itraconazole).
Source: FDA drug label - cinacalcet
Ketoconazole Combined administration of citalopram (40 mg) and ketoconazole (200 mg) decreased the C max and AUC of ketoconazole by 21% and 10%, respectively, and did not significantly affect the pharmacokinetics of citalopram.
Source: FDA drug label - citalopram
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of Codeine Sulfate Tablets and CYP3A4 inducers can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels [see Clinical Pharmacology ( 12.3 )] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence [see Warnings and Precautions ( 5.7 )] .
Source: FDA drug label - codeine sulfate
Drug Interactions: Pharmacokinetic Parameters for Colchicine Tablets in the Presence of the Coadministered Drug Coadministered Drug Dose of Coadministered Drug (mg) Dose of Colchicine Tablets (mg) N % Change in Colchicine Concentrations from Baseline (Range: Min – Max) C max AUC 0-t Cyclosporine 100 mg single dose 0.6 mg single dose 23 270.0 (62.0 to 606.9) 259.0 (75.8 to 511.9) Clarithromycin 250 mg twice daily, 7 days 0.6 mg single dose 23 227.2 (65.7 to 591.1) 281.5 (88.7 to 851.6) Ketoconazole 200 mg twice daily, 5 days 0.6 mg single dose 24 101.7 (19.6 to 219.0) 212.2 (76.7 to 419.6) Ritonavir 100 mg twice daily, 5 days 0.6 mg single dose 18 184.4 (79.2 to 447.4) 296.0 (53.8 to 924.4) Verapamil 240 mg daily, 5 days 0.6 mg single dose 24 40.1 (-47.1 to 149.5) 103.3 (-9.8 to 217.2) Diltiazem 240 mg daily, 7 days 0.6 mg single dose 20 44.2 (-46.0 to 318.3) 93.4 (-30.2 to 338.6) Azithromycin 500 mg x 1 day, then 250 mg x 4 days 0.6 mg single dose 21 21.6 (-41.7 to 222.0) 57.1 (-24.3 to 241.1) Grapefruit juice 240 mL twice daily, 4 days 0.6 mg single dose 21 -2.55 (-53.4 to 55.0) -2.36 (-46.4 to 62.2) Estrogen-containing oral contraceptives: In healthy female volunteers given ethinyl estradiol and norethindrone (Ortho-Novum ® 1/35) coadministered with colchicine tablets (0.6 mg twice daily × 14 days), hormone concentrations are not affected.
Source: FDA drug label - colchicine
Drugs That May Potentiate Renal Dysfunction Antibiotics Antineoplastics Antifungals Anti-inflammatory Drugs Gastrointestinal Agents Immunosuppressives Other Drugs ciprofloxacin melphalan amphotericin B azapropazon cimetidine tacrolimus fibric acid derivatives gentamicin ketoconazole colchicine ranitidine (e.g., bezafibrate, fenofibrate) tobramycin diclofenac methotrexate vancomycin naproxen trimethoprim with sulfamethoxazole sulindac During the concomitant use of a drug that may exhibit additive or synergistic renal impairment with cyclosporine, close monitoring of renal function (in particular serum creatinine) should be performed. Drugs That Increase Cyclosporine Concentrations Calcium Channel Blockers Antifungals Antibiotics Glucocorticoids Other Drugs diltiazem fluconazole azithromycin methylprednisolone Allopurinol nicardipine itraconazole clarithromycin Amiodarone verapamil ketoconazole erythromycin Bromocriptine voriconazole quinupristin/ dalfopristin colchicine danazol imatinib metoclopramide nefazodone oral contraceptives HIV Protease inhibitors The HIV protease inhibitors (e.g., indinavir, nelfinavir, ritonavir, and saquinavir) are known to inhibit cytochrome P-450 3A and thus could potentially increase the concentrations of cyclosporine, however no formal studies of the interaction are available.
Source: FDA drug label - cyclosporine
7 DRUG INTERACTIONS 7.1 Inhibitors of Cytochrome P450 3A4 In controlled clinical studies co-administration of desloratadine with ketoconazole, erythromycin, or azithromycin resulted in increased plasma concentrations of desloratadine and 3 hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine.
Source: FDA drug label - desloratadine
At present, this reaction is known to occur with cimetidine, ketoconazole, fluvoxamine, fluoxetine, and omeprazole.
Source: FDA drug label - diazepam
Conivaptan 33% 43% Diltiazem 20% NA Indomethacin 40% NA Mirabegron 29% 27% Nefazodone 27% 15% Nifedipine 45% NA Propantheline 24% 24% Quinine NA 33% Rabeprazole 29% 19% Saquinavir 27% 49% Spironolactone 25% NA Telmisartan 20 to 49% NA Tricagrelor 31% 28% Tolvaptan 30% 20% Trimethoprim 22 to 28% NA Digoxin concentrations increased, but magnitude is unclear Alprazolam, azithromycin, cyclosporine, diclofenac, diphenoxylate, epoprostenol, esomeprazole, ibuprofen, ketoconazole, lansoprazole, metformin, omeprazole Measure serum digoxin concentrations before initiating concomitant drugs.
Source: FDA drug label - digoxin
Although potent inhibitors of cytochrome P450 3A4 (e.g., ketoconazole) have not been studied clinically, in vitro studies have shown that erythromycin and oleandomycin inhibit the metabolism of disopyramide.
Source: FDA drug label - disopyramide phosphate
In vivo studies showed that the exposure of docetaxel increased 2.2-fold when it was coadministered with ketoconazole, a potent inhibitor of CYP3A4.
Source: FDA drug label - docetaxel
In vivo studies showed that the exposure of docetaxel increased 2.2-fold when it was coadministered with ketoconazole, a potent inhibitor of CYP3A4.
Source: FDA drug label - docetaxel anhydrous
Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in increases in the C max and AUC of tamsulosin by factors of 2.2 and 2.8, respectively. Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when tamsulosin 0.4 mg is coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin 0.4 mg capsules should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole).
Source: FDA drug label - dutasteride and tamsulosin hydrochloride capsules
Ketoconazole ↓ ketoconazole Drug interaction studies with efavirenz and ketoconazole have not been conducted. efavirenz has the potential to decrease plasma concentrations of ketoconazole.
Source: FDA drug label - efavirenz
Antifungals: oral Ketoconazole These interactions have been studied in healthy adults. ↑ EBR ↑ GZR Co-administration of oral ketoconazole is not recommended.
Source: FDA drug label - elbasvir and grazoprevir
No clinically significant drug interactions have been either observed or are expected when DESCOVY is combined with the following drugs: buprenorphine, itraconazole, ketoconazole, lorazepam, methadone, midazolam, naloxone, norbuprenorphine, norgestimate/ethinyl estradiol, and sertraline.
Source: FDA drug label - emtricitabine and tenofovir alafenamide
Clinically meaningful differences in exposure (AUC) were not observed in patients with advanced solid tumors when eribulin mesylate was administered with or without ketoconazole (a strong inhibitor of CYP3A4 and a P-gp inhibitor) and when eribulin mesylate was administered with or without rifampin (a CYP3A4 inducer) [see Clinical Pharmacology ( 12.3 )].
Source: FDA drug label - eribulin mesylate
7.16 Ketoconazole Combined administration of racemic citalopram (40 mg) and ketoconazole (200 mg), a potent CYP3A4 inhibitor, decreased the C max and AUC of ketoconazole by 21% and 10%, respectively, and did not significantly affect the pharmacokinetics of citalopram.
Source: FDA drug label - escitalopram
7.16 Ketoconazole Combined administration of racemic citalopram (40 mg) and ketoconazole (200 mg), a potent CYP3A4 inhibitor, decreased the C max and AUC of ketoconazole by 21% and 10%, respectively, and did not significantly affect the pharmacokinetics of citalopram.
Source: FDA drug label - escitalopram oxalate
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Esomeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity Intervention: Mycophenolate mofetil (MMF): Co-administration of omeprazole, of which esomeprazole is an enantiomer, in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH.
Source: FDA drug label - esomeprazole magnesium
Inhibitors of CYP3A4 such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir, and grapefruit juice may increase plasma concentrations of estrogens and may result in adverse reactions.
Source: FDA drug label - estradiol
Inhibitors of CYP3A4 such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice may increase plasma concentrations of estrogens and may result in adverse reactions.
Source: FDA drug label - estradiol and levonorgestrel
Strong CYP3A4 Inhibitors : Strong CYP3A4 inhibitors such as ketoconazole increased hormone serum concentrations. In a study investigating the effect of ketoconazole on dienogest and estradiol pharmacokinetics, co-administration with the strong CYP3A4 inhibitor ketoconazole resulted in a 186% increase of AUC (0–24hr) at steady state for dienogest and a 57% increase for estradiol. There was also a 94% and 65% increase of C max at steady state for dienogest and estradiol when co-administered with ketoconazole.
Source: FDA drug label - estradiol valerate and estradiol valerate/dienogest
Use with ethanol causes additive psychomotor impairment ( 7.1 ) • Rifampicin Combination use may decrease exposure and effects of eszopiclone tablets ( 7.2 ) • Ketoconazole Combination use increases exposure and effect of eszopiclone tablets. 7.2 Drugs that Inhibit or Induce CYP3A4 Drugs that Inhibit CYP3A4 (Ketoconazole) CYP3A4 is a major metabolic pathway for elimination of eszopiclone. The exposure of eszopiclone was increased by coadministration of ketoconazole, a potent inhibitor of CYP3A4.
Source: FDA drug label - eszopiclone
Antifungals : itraconazole ketoconazole posaconazole ↑ etravirine ↓ itraconazole ↓ ketoconazole ↔ posaconazole Posaconazole, a potent inhibitor of CYP3A4, may increase plasma concentrations of etravirine. Itraconazole and ketoconazole are potent inhibitors as well as substrates of CYP3A4. Concomitant systemic use of itraconazole or ketoconazole and etravirine tablets may increase plasma concentrations of etravirine.
Source: FDA drug label - etravirine
Table 1: Drugs That Affect Phenytoin Concentrations Interacting Agent Examples Drugs that may increase phenytoin serum levels Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole trimethoprim Other Acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, disulfiram, estrogen, fluvastatin, isoniazid, methylphenidate, phenothiazines, salicylates, ticlopidine, tolbutamide, trazodone, warfarin Drugs that may decrease phenytoin serum levels Antineoplastic agents usually in combination Bleomycin, carboplatin, cisplatin, doxorubicin, methotrexate Antiviral agents Fosamprenavir, nelfinavir, ritonavir Antiepileptic drugs Carbamazepine, vigabatrin Other Chronic alcohol abuse, diazepam, diazoxide, folic acid, reserpine, rifampin, St. Table 2: Drugs Affected by Phenytoin Interacting Agent Examples Drugs whose efficacy is impaired by phenytoin Azoles Fluconazole, ketoconazole, itraconazole, posaconazole, voriconazole Antineoplastic agents Irinotecan, paclitaxel, teniposide Delavirdine Phenytoin can substantially reduce the concentrations of delavirdine.
Source: FDA drug label - extended phenytoin sodium
See the prescribing information for other drugs dependent on gastric pH for absorption for administration instructions, including atazanavir, erlotinib, ketoconazole, itraconazole, ledipasvir/sofosbuvir, nilotinib, and rilpivirine.
Source: FDA drug label - famotidine
Co-administration of CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, erythromycin, grapefruit juice, cimetidine) with felodipine may lead to several-fold increases in the plasma levels of felodipine, either due to an increase in bioavailability or due to a decrease in metabolism.
Source: FDA drug label - felodipine
ketoconazole), protease inhibitors (e.g., ritonavir), grapefruit juice CYP3A4 Inducers Clinical Impact: The concomitant use of Fentanyl Citrate Injection and CYP3A4 inducers can decrease the plasma concentration of fentanyl [see Clinical Pharmacology ( 12.3 )] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to fentanyl [see Warnings and Precautions ( 5.4 )] .
Source: FDA drug label - fentanyl citrate
Additionally, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than fluoxetine or norfluoxetine as an inhibitor of the metabolism of several substrates for this enzyme, including astemizole, cisapride, and midazolam.
Source: FDA drug label - fluoxetine
Additionally, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than fluoxetine or norfluoxetine as an inhibitor of the metabolism of several substrates for this enzyme, including astemizole, cisapride, and midazolam.
Source: FDA drug label - fluoxetine hydrochloride
7 DRUG INTERACTIONS Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with FLOVENT DISKUS is not recommended because increased systemic corticosteroid adverse effects may occur. Ketoconazole Coadministration of orally inhaled fluticasone propionate (1,000 mcg) and ketoconazole (200 mg once daily) resulted in a 1.9-fold increase in plasma fluticasone propionate exposure and a 45% decrease in plasma cortisol area under the curve (AUC), but had no effect on urinary excretion of cortisol.
Source: FDA drug label - fluticasone propionate
• Strong Cytochrome P450 3A4 Inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with fluticasone propionate and salmeterol inhalation powder is not recommended because increased systemic corticosteroid and increased cardiovascular adverse effects may occur. Ketoconazole Fluticasone Propionate: Coadministration of orally inhaled fluticasone propionate (1,000 mcg) and ketoconazole (200 mg once daily) resulted in a 1.9-fold increase in plasma fluticasone propionate exposure and a 45% decrease in plasma cortisol area under the curve (AUC), but had no effect on urinary excretion of cortisol.
Source: FDA drug label - fluticasone propionate and salmeterol
The metabolism of fluvoxamine has not been fully characterized and the effects of potent cytochrome P450 isoenzyme inhibition, such as the ketoconazole inhibition of CYP3A4, on fluvoxamine metabolism have not been studied.
Source: FDA drug label - fluvoxamine maleate
Although, fulvestrant is metabolized by CYP 3A4 in vitro , drug interactions studies with ketoconazole or rifampin did not alter fulvestrant pharmacokinetics.
Source: FDA drug label - fulvestrant
CYP3A4 Inhibitor Drugs that are strong inhibitors of CYP3A4 (e.g., ketoconazole and itraconazole) decrease gefitinib metabolism and increase gefitinib plasma concentrations.
Source: FDA drug label - gefitinib
Examples include: CYP3A4 inhibitors - alprazolam; itraconazole, ketoconazole, nefazodone, ritonavir. Increases in QTc have been observed when haloperidol was given with a combination of the metabolic inhibitors ketoconazole (400 mg/day) and paroxetine (20 mg/day).
Source: FDA drug label - haloperidol decanoate
Drug Interactions Inhibitors of CYP3A4 and CYP2D6 The concomitant use of hydrocodone bitartrate and acetaminophen tablets and CYP3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir), can increase the plasma concentration of the hydrocodone from hydrocodone bitartrate and acetaminophen tablets, resulting in increased or prolonged opioid effects.
Source: FDA drug label - hydrocodone bitartrate and acetaminophen
ketoconazole), or protease inhibitors (e.g., ritonavir), can increase the plasma concentration of hydrocodone, resulting in increased or prolonged opioid effects.
Source: FDA drug label - hydrocodone polistirex and chlorpheniramine polistirex
Drugs such as troleandomycin and ketoconazole may inhibit the metabolism of corticosteroids and thus decrease their clearance.
Source: FDA drug label - hydrocortisone
Ketoconazole Potential interaction of ketoconazole and isoniazid may exist. When ketoconazole is given in combination with isoniazid and rifampin the AUC of ketoconazole is decreased by as much as 88 percent after 5 months of concurrent isoniazid and rifampin therapy 4 .
Source: FDA drug label - isoniazid
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Lansoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - lansoprazole
7.1 Antipyrine, Azithromycin, Cimetidine, Erythromycin, Ketoconazole, Theophylline, and Pseudoephedrine Pharmacokinetic interaction studies performed with racemic cetirizine demonstrated that cetirizine did not interact with antipyrine, pseudoephedrine, erythromycin, azithromycin, ketoconazole, and cimetidine.
Source: FDA drug label - levocetirizine dihydrochloride
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase systemic exposure of estrogen and/or progestin component of COCs.
Source: FDA drug label - levonorgestrel and ethinyl estradiol
Although not observed in the lopinavir and ritonavir /ketoconazole drug interaction study, co-administration of lopinavir and ritonavir and other drugs that inhibit CYP3A may increase lopinavir plasma concentrations. Antifungals: ketoconazole*, itraconazole, voriconazole isavuconazonium sulfate* ↑ ketoconazole ↑ itraconazole ↓ voriconazole ↑ isavuconazonium High doses of ketoconazole (>200 mg/day) or itraconazole (> 200 mg/day) are not recommended.
Source: FDA drug label - lopinavir and ritonavir
Conversion of losartan to its active metabolite after intravenous administration is not affected by ketoconazole, an inhibitor of P450 3A4. Ketoconazole did not affect the conversion of losartan to the active metabolite after intravenous administration of losartan, and erythromycin had no clinically significant effect after oral administration.
Source: FDA drug label - losartan potassium and hydrochlorothiazide
Strong inhibitors of CYP3A4 (e.g., itraconazole, ketoconazole, posaconazole, voriconazole, clarithromycin, telithromycin, HIV protease inhibitors, boceprevir, telaprevir, nefazodone, erythromycin, and cobicistat-containing products), and grapefruit juice increase the risk of myopathy by reducing the elimination of lovastatin (see CONTRAINDICATIONS , WARNINGS , Myopathy/Rhabdomyolysis , and CLINICAL PHARMACOLOGY , Pharmacokinetics ).
Source: FDA drug label - lovastatin
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 and CYP2B6 Inducers Clinical Impact: The concomitant use of meperidine and CYP3A4 or CYP2B6 inducers can decrease the plasma concentration of meperidine [see Clinical Pharmacology ( 12.3 )], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to meperidine [see Warnings and Precautions ( 5.7 )].
Source: FDA drug label - meperidine hydrochloride
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir), fluconazole, fluvoxamine, Some selective serotonin reuptake inhibitors (SSRIs) (e.g., sertraline, fluvoxamine) Inducers of CYP3A4, CYP2B6, CYP2C19, or CYP2C9 Clinical Impact: The concomitant use of Methadone Hydrochloride Injection and CYP3A4, CYP2B6, CYP2C19, or CYP2C9 inducers can decrease the plasma concentration of methadone (see CLINICAL PHARMACOLOGY ), resulting in decreased efficacy or onset of withdrawal symptoms in patients physically dependent on methadone.
Source: FDA drug label - methadone hydrochloride
Examples of some of the more potent CYP 3A4 inhibitors include macrolide antibiotics (e.g., erythromycin, troleandomycin, clarithromycin), HIV protease or reverse transcriptase inhibitors (e.g., ritonavir, indinavir, nelfinavir, delavirdine) or azole antifungals (e.g., ketoconazole, itraconazole, voriconazole).
Source: FDA drug label - methylergonovine maleate
Drugs such as troleandomycin and ketoconazole may inhibit the metabolism of methylprednisolone and thus decrease its clearance.
Source: FDA drug label - methylprednisolone
Drugs such as diltiazem, erythromycin, fluconazole, itraconazole, ketoconazole, saquinavir, and verapamil were shown to significantly increase the C max and AUC of orally administered midazolam.
Source: FDA drug label - midazolam hydrochloride
Drug interaction studies were conducted in adult patients to investigate the effect of coadministered drugs on the pharmacokinetics of mirabegron and the effect of mirabegron on the pharmacokinetics of coadministered drugs (e.g., ketoconazole, rifampin, solifenacin succinate, tamsulosin, and oral contraceptives) [see Clinical Pharmacology ( 12.3 )] .
Source: FDA drug label - mirabegron
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, mycophenoloate mofetil, ketoconazole) Clinical Impact: Esomeprazole magnesium can reduce the absorption of other drugs due to its effect on reducing intragastric acidity Intervention: Mycophenolate mofetil (MMF): Co-administration of omeprazole, of which esomeprazole magnesium is an enantiomer, in healthy subjects and in transplant patients receiving MMF has been reported to reduce the exposure to the active metabolite, mycophenolic acid (MPA), possibly due to a decrease in MMF solubility at an increased gastric pH.
Source: FDA drug label - naproxen and esomeprazole magnesium
CYP3A Inhibitors CYP3A inhibitors such as ketoconazole, fluconazole, itraconazole, clarithromycin, erythromycin (Azithromycin, although structurally related to the class of macrolide antibiotic is void of clinically relevant CYP3A4 inhibition), grapefruit, nefazodone, fluoxetine, saquinavir, indinavir, nelfinavir, and ritonavir may result in increased exposure to nifedipine when co-administered.
Source: FDA drug label - nifedipine
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations.
Source: FDA drug label - norelgestromin and ethinyl estradiol
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations.
Source: FDA drug label - norethindrone acetate and ethinyl estradiol
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations.
Source: FDA drug label - norethindrone and ethinyl estradiol
CYP3A4 inhibitors such as itraconazole, voriconazole, fluconazole, grapefruit juice, or ketoconazole may increase plasma hormone concentrations.
Source: FDA drug label - norgestimate and ethinyl estradiol
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Omeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - omeprazole
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Omeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - omeprazole, sodium bicarbonate
Mean oxybutynin chloride plasma concentrations were approximately 2 fold higher when Oxybutynin chloride extended-release tablets were administered with ketoconazole, a potent CYP3A4 inhibitor. (7) Co-administration with strong cytochrome P450 (CYP) 3A4 inhibitors (e.g., ketoconazole) increases the systemic exposure of oxybutynin.
Source: FDA drug label - oxybutynin chloride
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir).
Source: FDA drug label - oxycodone
ketoconazole), and protease inhibitors (e.g., ritonavir), can increase the plasma concentration of oxycodone, resulting in increased or prolonged opioid effects.
Source: FDA drug label - oxycodone and acetaminophen
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir).
Source: FDA drug label - oxycodone hydrochloride
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of Oxycodone Hydrochloride Oral Solution and CYP3A4 inducers can decrease the plasma concentration of oxycodone [see Clinical Pharmacology (12.3) ], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to oxycodone [see Warnings and Precautions (5.6) ].
Source: FDA drug label - oxycodone hydrochloride oral solution
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole / itraconazole ) Clinical Impact: Pantoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - pantoprazole
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Pantoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - pantoprazole sodium
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Pantoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - pantoprazole sodium delayed-release
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Impact: Pantoprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - pantoprazole sodium granules
Hence, exposure of paricalcitol will increase upon coadministration with strong CYP3A inhibitors such as but not limited to: boceprevir, clarithromycin, conivaptan, grapefruit juice, indinavir, itraconazole, ketoconazole, lopinavir/ritonavir, mibefradil, nefazodone, nelfinavir, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, voriconazole. ketoconazole) will increase the exposure of paricalcitol.
Source: FDA drug label - paricalcitol
In addition, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than paroxetine as an inhibitor of the metabolism of several substrates for this enzyme, including terfenadine, astemizole, cisapride, triazolam, and cyclosporine.
Source: FDA drug label - paroxetine
In addition, in vitro studies have shown ketoconazole, a potent inhibitor of CYP3A4 activity, to be at least 100 times more potent than paroxetine as an inhibitor of the metabolism of several substrates for this enzyme, including terfenadine, astemizole, cisapride, triazolam, and cyclosporine.
Source: FDA drug label - paroxetine hydrochloride
Table 2: Drugs That Affect Phenytoin Concentrations Interacting Agent Examples Drugs that may increase phenytoin serum levels Antiepileptic drugs Ethosuximide, felbamate, oxcarbazepine, methsuximide, topiramate Azoles Fluconazole, ketoconazole, itraconazole, miconazole, voriconazole Antineoplastic agents Capecitabine, fluorouracil Antidepressants Fluoxetine, fluvoxamine, sertraline Gastric acid reducing agents H 2 antagonists (cimetidine), omeprazole Sulfonamides Sulfamethizole, sulfaphenazole, sulfadiazine, sulfamethoxazole-trimethoprim Other Acute alcohol intake, amiodarone, chloramphenicol, chlordiazepoxide, disulfiram, estrogen, fluvastatin, isoniazid, methylphenidate, phenothiazines, salicylates, ticlopidine, tolbutamide, trazodone, warfarin Drugs that may decrease phenytoin serum levels Antacids Antacids may affect absorption of phenytoin. Table 3: Drugs Affected by Phenytoin Interacting Agent Examples Drugs whose efficacy is impaired by phenytoin Azoles Fluconazole, ketoconazole, itraconazole, posaconazole, voriconazole Antineoplastic agents Irinotecan, paclitaxel, teniposide Delavirdine Phenytoin can substantially reduce the concentrations of delavirdine.
Source: FDA drug label - phenytoin
Drugs such as troleandomycin and ketoconazole may inhibit the metabolism of corticosteroids and thus decrease their clearance.
Source: FDA drug label - prednisone
(7.6) 7.1 CYP2D6 and CYP3A4 Inhibitors Drugs that inhibit CYP2D6 (such as desipramine, paroxetine, ritonavir, sertraline) and CYP3A4 (such as ketoconazole, ritonavir, saquinavir, erythromycin, grapefruit juice) can be expected to cause increased plasma levels of propafenone.
Source: FDA drug label - propafenone hydrochloride
7 DRUG INTERACTIONS Concomitant use of strong CYP3A4 inhibitors: Reduce quetiapine dose to one sixth when coadministered with strong CYP3A4 inhibitors (e.g., ketoconazole, ritonavir) ( 2.5 , 7.1 , 12.3 ) Concomitant use of strong CYP3A4 inducers: Increase quetiapine dose up to 5 fold when used in combination with a chronic treatment (more than 7-14 days) of potent CYP3A4 inducers (e.g., phenytoin, rifampin, St. Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype CYP3A4 inducers (e.g., phenytoin, carbamazepine, rifampin, avasimibe, St. CYP3A4 inhibitors: Coadministration of ketoconazole, a potent inhibitor of cytochrome CYP3A4, resulted in significant increase in quetiapine exposure.
Source: FDA drug label - quetiapine
ketoconazole, ritonavir) ( 7.1 , 12.3 ) Concomitant Use of Strong CYP3A4 Inducers: Increase quetiapine dose up to 5 fold when used in combination with a chronic treatment (more than 7 to 14 days) of potent CYP3A4 inducers (e.g. Quetiapine exposure is increased by the prototype CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, indinavir, ritonavir, nefazodone, etc.) and decreased by the prototype CYP3A4 inducers (e.g, phenytoin, carbamazepine, rifampin, avasimibe, St. CYP3A4 Inhibitors Coadministration of ketoconazole, a potent inhibitor of cytochrome CYP3A4, resulted in significant increase in quetiapine exposure.
Source: FDA drug label - quetiapine fumarate
Drugs Dependent on Gastric pH for Absorption (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole, itraconazole) Clinical Impact: Rabeprazole can reduce the absorption of other drugs due to its effect on reducing intragastric acidity.
Source: FDA drug label - rabeprazole sodium
Azole Antifungal Agents: fluconazole itraconazole ketoconazole This interaction study has been performed with a dose higher than the recommended dose for EDURANT assessing the maximal effect on the coadministered drug. posaconazole voriconazole ↑ rilpivirine ↓ ketoconazole Concomitant use of EDURANT or EDURANT PED with azole antifungal agents may cause an increase in the plasma concentrations of rilpivirine (inhibition of CYP3A enzymes).
Source: FDA drug label - rilpivirine hydrochloride
Antifungals: ketoconazole itraconazole voriconazole ↑ ketoconazole ↑ itraconazole ↓ voriconazole High doses of ketoconazole or itraconazole (greater than 200 mg per day) are not recommended.
Source: FDA drug label - ritonavir
Coadministration of a selective and potent inhibitor of CYP3A4, ketoconazole (100 mg bid for 2 days with ropivacaine infusion administered 1 hour after ketoconazole) caused a 15% reduction in in vivo plasma clearance of ropivacaine.
Source: FDA drug label - ropivacaine hydrochloride
Examples Boceprevir, clarithromycin, cobicistat, conivaptan, danoprevir and ritonavir, diltiazem, elvitegravir and ritonavir, grapefruit juice a , idelalisib, indinavir and ritonavir, itraconazole, ketoconazole, lopinavir and ritonavir, nefazodone, nelfinavir, paritaprevir and ritonavir and (ombitasvir and/or dasabuvir), posaconazole, ritonavir, saquinavir and ritonavir, tipranavir and ritonavir, troleandomycin, voriconazole Strong CYP3A Inducers Clinical Impact Coadministration of RYDAPT with strong CYP3A inducers may decrease midostaurin concentrations [see Clinical Pharmacology (12.3)].
Source: FDA drug label - rydapt
7 DRUG INTERACTIONS • Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with SEREVENT DISKUS is not recommended because increased cardiovascular adverse effects may occur. In a drug interaction trial in 20 healthy subjects, coadministration of inhaled salmeterol (50 mcg twice daily) and oral ketoconazole (400 mg once daily) for 7 days resulted in greater systemic exposure to salmeterol (AUC increased 16-fold and C max increased 1.4-fold).
Source: FDA drug label - salmeterol xinafoate
Examples: Select azole anti-fungals (e.g., itraconazole, ketoconazole, posaconazole, and voriconazole), select macrolide antibiotics (e.g., erythromycin and clarithromycin), select HIV protease inhibitors (e.g., nelfinavir, ritonavir, and darunavir/ritonavir), select HCV protease inhibitors (e.g., boceprevir and telaprevir), cobicistat-containing products, and nefazodone.
Source: FDA drug label - simvastatin
7.4 Drugs without Clinically Significant Interactions with VOSEVI Based on drug interaction studies conducted with the components of VOSEVI (sofosbuvir, velpatasvir, and/or voxilaprevir) or VOSEVI, no clinically significant drug interactions have been observed with the following drugs [see Clinical Pharmacology (12.3) ]: VOSEVI: cobicistat, darunavir, elvitegravir, emtricitabine, ethinyl estradiol/norgestimate, gemfibrozil, rilpivirine, ritonavir, tenofovir alafenamide, voriconazole Sofosbuvir/velpatasvir: dolutegravir, ketoconazole, raltegravir Sofosbuvir: methadone, tacrolimus
Source: FDA drug label - sofosbuvir, velpatasvir, and voxilaprevir
Concomitant use of ketoconazole, a strong CYP3A4 inhibitor, significantly increased the exposure of solifenacin [ see Clinical Pharmacology ( 12.3 ) ].
Source: FDA drug label - solifenacin succinate
Drug Interactions Some studies have shown that simultaneous sucralfate administration in healthy volunteers reduced the extent of absorption (bioavailability) of single doses of the following: cimetidine, digoxin, fluoroquinolone antibiotics, ketoconazole, l-thyroxine, phenytoin, quinidine, ranitidine, tetracycline, and theophylline.
Source: FDA drug label - sucralfate
ketoconazole, ritonavir) increase tadalafil exposure ( 2.7 , 5.10 , 7.2 ) requiring dose adjustment: Tadalafil tablets for use as needed: no more than 10 mg every 72 hours Tadalafil tablets for once daily use: dose not to exceed 2.5 mg CYP3A4 inducers (e.g. CYP3A4 (e.g., Ketoconazole) — Ketoconazole (400 mg daily), a selective and potent inhibitor of CYP3A4, increased tadalafil 20 mg single-dose exposure (AUC) by 312% and C max by 22%, relative to the values for tadalafil 20 mg alone. Ketoconazole (200 mg daily) increased tadalafil 10-mg single-dose exposure (AUC) by 107% and C max by 15%, relative to the values for tadalafil 10 mg alone [see Dosage and Administration ( 2.7 )] .
Source: FDA drug label - tadalafil
7 DRUG INTERACTIONS • Tamsulosin hydrochloride capsules 0.4 mg should not be used with strong inhibitors of CYP3A4 (e.g., ketoconazole). Concomitant treatment with ketoconazole (a strong inhibitor of CYP3A4) resulted in an increase in the C max and AUC of tamsulosin by a factor of 2.2 and 2.8, respectively [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]. Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when tamsulosin hydrochloride capsules 0.4 mg is coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin hydrochloride capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole) [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].
Source: FDA drug label - tamsulosin hydrochloride
However, strong inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, ritonavir) may increase the plasma concentrations of amlodipine to a greater extent.
Source: FDA drug label - telmisartan and amlodipine
Based on this finding, it is likely that other inhibitors of both CYP2C9 and CYP3A4 (e.g., ketoconazole, amiodarone) may also lead to a substantial increase in the systemic exposure (C max and AUC) of terbinafine when concomitantly administered.
Source: FDA drug label - terbinafine
Based on this finding, it is likely that other inhibitors of both CYP2C9 and CYP3A4 (e.g., ketoconazole, amiodarone) may also lead to a substantial increase in the systemic exposure (C max and AUC) of terbinafine when concomitantly administered.
Source: FDA drug label - terbinafine hydrochloride
Drugs that have been documented not to interact with theophylline or drugs that produce no clinically significant interaction with theophylline.* albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without methylprednisolone sulbactam metronidazole atenolol metoprolol azithromycin nadolol caffeine, dietary ingestion nifedipine cefaclor nizatidine co-trimoxazole (trimethoprim and sulfamethoxazole) norfloxacin ofloxacin diltiazem omeprazole dirithromycin prednisone, prednisolone enflurane ranitidine famotidine rifabutin felodipine roxithromycin finasteride Sorbitol (purgative doses do not inhibit hydrocortisone theophylline absorption) isoflurane sucralfate isoniazid terbutaline, systemic isradipine terfenadine influenza vaccine tetracycline ketoconazole tocainide lomefloxacin * Refer to PRECAUTIONS, Drug Interactions for information regarding table.
Source: FDA drug label - theophylline
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline, systemic influenza vaccine terfenadine ketoconazole tetracycline lomefloxacin tocainide
Source: FDA drug label - theophylline anhydrous
7.7 Inhibitors of Cytochrome P450 and P-gp Efflux Transporter In a drug interaction study using the strong dual CYP and P-gp inhibitor ketoconazole, a 1.7-fold increase of olodaterol maximum plasma concentrations and AUC was observed [see Pharmacokinetics (12.3) ] .
Source: FDA drug label - tiotropium bromide and olodaterol
7.2 Potent CYP3A4 Inhibitors Ketoconazole (200 mg daily), a potent CYP3A4 inhibitor, increased the mean C max and AUC of tolterodine by 2- and 2.5-fold, respectively, in CYP2D6 poor metabolizers. For patients receiving ketoconazole or other potent CYP3A4 inhibitors such as itraconazole, clarithromycin, or ritonavir, the recommended dose of tolterodine tartrate extended-release capsules is 2 mg once daily [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3) ] . Potent CYP3A4 Inhibitors The effect of a 200 mg daily dose of ketoconazole on the pharmacokinetics of tolterodine immediate release was studied in 8 healthy volunteers, all of whom were CYP2D6 poor metabolizers.
Source: FDA drug label - tolterodine tartrate
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology (12.3)] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol, [see Warnings and Precautions (5.7)] .
Source: FDA drug label - tramadol hcl er
ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride extended-release tablets and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology ( 12.3 )] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol, [see Warnings and Precautions ( 5.
Source: FDA drug label - tramadol hydrochloride
Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of tramadol hydrochloride and acetaminophen and CYP3A4 inducers can decrease the plasma concentration of tramadol [see Clinical Pharmacology (12.3) ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to tramadol.
Source: FDA drug label - tramadol hydrochloride and acetaminophen
It is likely that ketoconazole, indinavir, and other CYP3A4 inhibitors such as itraconazole may lead to substantial increases in trazodone plasma concentrations with the potential for adverse effects. Examples: itraconazole, ketoconazole, clarithromycin, indinavir Strong CYP3A4 Inducers Clinical Impact: The concomitant use of trazodone and strong CYP3A4 inducers decreased the exposure of trazodone compared to the use of trazodone alone .
Source: FDA drug label - trazodone hydrochloride
In vivo studies Strong CYP3A4 inhibitors Ketoconazole (200 mg once daily) produced a 10-fold increase in vardenafil AUC and a 4-fold increase in maximum concentration (C max ) when co-administered with vardenafil hydrochloride tablets (5 mg) in healthy volunteers. A 5-mg vardenafil hydrochloride tablet dose should not be exceeded in a 24-hour period when used in combination with 200 mg once daily ketoconazole. Since higher doses of ketoconazole (400 mg daily) may result in higher increases in C max and AUC, a single 2.5 mg dose of vardenafil hydrochloride tablets should not be exceeded in a 24-hour period when used in combination with ketoconazole 400 mg daily.
Source: FDA drug label - vardenafil hydrochloride
Ketoconazole A pharmacokinetic study with ketoconazole 100 mg b.i.d. with a single dose of venlafaxine 50 mg in extensive metabolizers (EM; n = 14) and 25 mg in poor metabolizers (PM; n = 6) of CYP2D6 resulted in higher plasma concentrations of both venlafaxine and O-desvenlafaxine (ODV) in most subjects following administration of ketoconazole.
Source: FDA drug label - venlafaxine
Ketoconazole A pharmacokinetic study with ketoconazole 100 mg b.i.d. with a single dose of venlafaxine 50 mg in extensive metabolizers (EM; n = 14) and and 25 mg in poor metabolizers (PM; n = 6) of CYP2D6, respectively, resulted in higher plasma concentrations of both venlafaxine and O-desvenlafaxine (ODV) in most subjects following administration of ketoconazole.
Source: FDA drug label - venlafaxine hydrochloride
Other Drugs (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Effect Vonoprazan reduces intragastric acidity [see Clinical Pharmacology (12.2) ] , which may decrease the absorption of drugs reducing their effectiveness. Other Drugs (e.g., iron salts, erlotinib, dasatinib, nilotinib, mycophenolate mofetil, ketoconazole/itraconazole) Clinical Effect Vonoprazan reduces intragastric acidity [see Clinical Pharmacology (12.2) ] , which may decrease the absorption of drugs reducing their effectiveness.
Source: FDA drug label - vonoprazan fumarate
Table 2: Examples of CYP450 Interactions with Warfarin Enzyme Inhibitors Inducers CYP2C9 amiodarone, capecitabine, cotrimoxazole, etravirine, fluconazole, fluvastatin, fluvoxamine, metronidazole, miconazole, oxandrolone, sulfinpyrazone, tigecycline, voriconazole, zafirlukast aprepitant, bosentan, carbamazepine, phenobarbital, rifampin CYP1A2 acyclovir, allopurinol, caffeine, cimetidine, ciprofloxacin, disulfiram, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, norfloxacin, oral contraceptives, phenylpropanolamine, propafenone, propranolol, terbinafine, thiabendazole, ticlopidine, verapamil, zileuton montelukast, moricizine, omeprazole, phenobarbital, phenytoin, cigarette smoking CYP3A4 alprazolam, amiodarone, amlodipine, amprenavir, aprepitant, atorvastatin, atazanavir, bicalutamide, cilostazol, cimetidine, ciprofloxacin, clarithromycin, conivaptan, cyclosporine, darunavir/ritonavir, diltiazem, erythromycin, fluconazole, fluoxetine, fluvoxamine, fosamprenavir, imatinib, indinavir, isoniazid, itraconazole, ketoconazole, lopinavir/ritonavir, nefazodone, nelfinavir, nilotinib, oral contraceptives, posaconazole, ranitidine, ranolazine, ritonavir, saquinavir, telithromycin, tipranavir, voriconazole, zileuton armodafinil, amprenavir, aprepitant, bosentan, carbamazepine, efavirenz, etravirine, modafinil, nafcillin, phenytoin, pioglitazone, prednisone, rifampin, rufinamide 7.3 Drugs that Increase Bleeding Risk Examples of drugs known to increase the risk of bleeding are presented in Table 3 .
Source: FDA drug label - warfarin sodium
Ketoconazole Ketoconazole, a potent inhibitor of CYP3A4, at a dose of 400 mg QD for 5 days, increased the AUC and C max of ziprasidone by about 35 to 40%.
Source: FDA drug label - ziprasidone
Ketoconazole Ketoconazole, a potent inhibitor of CYP3A4, at a dose of 400 mg QD for 5 days, increased the AUC and C max of ziprasidone by about 35 to 40%.
Source: FDA drug label - ziprasidone hydrochloride
John's wort): Combination use may decrease effect ( 7.2 ) Ketoconazole: Combination use may increase effect ( 7.2 ) 7.1 CNS-Active Drugs CNS Depressants Coadministration of Zolpidem with other CNS depressants increases the risk of CNS depression. CYP3A4 Inhibitors Ketoconazole Ketoconazole, a potent CYP3A4 inhibitor, increased the exposure to and pharmacodynamic effects of Zolpidem.
Source: FDA drug label - zolpidem tartrate