] 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 )] .
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
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
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
( 7.1 ) 7.1 Effect of Other Drugs on TALZENNA Effect of P-gp Inhibitors Breast Cancer Avoid coadministration of TALZENNA with the following P-gp inhibitors: itraconazole, amiodarone, carvedilol, clarithromycin, itraconazole, and verapamil.
Source: FDA drug label - talazoparib
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
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
Antifungals: Itraconazole Use With Caution Itraconazole: Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when administered concomitantly (see also Itraconazole under “Drugs That Affect Clarithromycin Tablets” in the table below). Clarithromycin may increase the plasma concentrations of itraconazole. Patients taking itraconazole and clarithromycin concomitantly should be monitored closely for signs or symptoms of increased or prolonged adverse reactions.
Source: FDA drug label - clarithromycin
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
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.
Source: FDA drug label - drospirenone and ethinyl estradiol
[See Clinical Pharmacology (12.3).] Substances Increasing the Systemic Exposure of COCs (enzyme inhibitors): Concomitant administration of moderate or strong CYP3A4 inhibitors like azole antifungals (for example, ketoconazole, itraconazole, voriconazole, fluconazole), verapamil, macrolides (for example, clarithromycin, erythromycin), diltiazem, and grapefruit increase the serum concentrations of both estradiol and dienogest.
Source: FDA drug label - estradiol valerate and estradiol valerate/dienogest
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
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
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
Intervention: In patients taking clarithromycin or itraconazole, do not exceed atorvastatin 20 mg [see Dosage and Administration ( 2 )] . 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
( 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
7 DRUG INTERACTIONS Dosage adjustment due to drug interactions (7.1): Factors Dosage Adjustments for Aripiprazole Known CYP2D6 Poor Metabolizers Administer half of usual dose Known CYP2D6 Poor Metabolizers and strong CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP2D6 or CYP3A4 inhibitors Administer half of usual dose Strong CYP2D6 and CYP3A4 inhibitors Administer a quarter of usual dose Strong CYP3A4 inducers Double usual dose over 1 to 2 weeks 7.1 Drugs Having Clinically Important Interactions with Aripiprazole Table 25: Clinically Important Drug Interactions with Aripiprazole: Concomitant Drug Name or Drug Class Clinical Rationale Clinical Recommendation Strong CYP3A4 Inhibitors (e.g., itraconazole, clarithromycin) or strong CYP2D6 inhibitors (e.g., quinidine, fluoxetine, paroxetine) The concomitant use of aripiprazole with strong CYP 3A4 or CYP2D6 inhibitors increased the exposure of aripiprazole compared to the use of aripiprazole alone [see Clinical Pharmacology (12.3)].
Source: FDA drug label - aripiprazole
Examples: itraconazole, clarithromycin, quinidine, fluoxetine, paroxetine Strong CYP3A4 Inducers Clinical Impact: The concomitant use of oral aripiprazole and carbamazepine decreased the exposure of aripiprazole compared to the use of oral aripiprazole alone [see Clinical Pharmacology ( 12.3 )].
Source: FDA drug label - aripiprazole lauroxil
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
Intervention: In patients taking clarithromycin or itraconazole, do not exceed atorvastatin 20 mg [see Dosage and Administration (2.5) ]. Examples: Erythromycin, clarithromycin, itraconazole, ketoconazole, posaconazole, and voriconazole.
Source: FDA drug label - atorvastatin calcium
Inhibitors of CYP3A4 (e.g., ketoconazole, itraconazole, ritonavir, indinavir, saquinavir, erythromycin, and cyclosporine) can increase systemic budesonide concentrations [see Clinical Pharmacology (12.3) ] .
Source: FDA drug label - budesonide
Itraconazole In a study in healthy volunteers, coadministration of buspirone (10 mg as a single dose) with itraconazole (200 mg/day for 4 days) increased plasma buspirone concentrations (13 fold increase in C max and 19 fold increase in AUC).
Source: FDA drug label - buspirone
Itraconazole: In a study in healthy volunteers, coadministration of buspirone (10 mg as a single dose) with itraconazole (200 mg/day for 4 days) increased plasma buspirone concentrations (13 fold increase in C max and 19 fold increase in AUC).
Source: FDA drug label - buspirone hydrochloride
7 DRUG INTERACTIONS Drugs that Decrease Busulfan Clearance: Metronidazole, itraconazole, iron chelating agents, acetaminophen. ( 7.2 ) 7.1 Drugs that Decrease Busulfan Clearance Itraconazole decreases busulfan clearance by up to 25%. Metronidazole decreases the clearance of busulfan to a greater extent than does itraconazole; metronidazole coadministration has been associated with increased busulfan toxicity.
Source: FDA drug label - busulfan
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. In addition, carbamazepine causes, or would be expected to cause, decreased levels of the following drugs, for which monitoring of concentrations or dosage adjustment may be necessary: acetaminophen, albendazole, alprazolam, aprepitant, buprenorphone, bupropion, citalopram, clonazepam, clozapine, corticosteroids (e.g., prednisolone, dexamethasone), cyclosporine, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, ethosuximide, everolimus, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, methadone, methsuximide, mianserin, midazolam, olanzapine, oral and other hormonal contraceptives, oxcarbazepine, paliperidone, phensuximide, phenytoin, praziquantel, protease inhibitors, risperidone, sertraline, sirolimus, tadalafil, theophylline, tiagabine, topiramate, tramadol, trazodone, tricyclic antidepressants (e.g., imipramine, amitriptyline, nortriptyline), valproate, warfarin, ziprasidone, zonisamide.
Source: FDA drug label - carbamazepine
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
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
Co-administration with other drugs which strongly inhibit CYP 3A4 (e.g., itraconazole, clarithromycin, ritonavir, cobicistat-containing products) may lead to increased plasma concentrations of corticosteroids and potentially increase the risk for systemic corticosteroid side effects.
Source: FDA drug label - dexamethasone
Captopril 58% 39% Clarithromycin NA 70% Dronedarone NA 150% Gentamicin 129-212% NA Erythromycin 100% NA Itraconazole 80% NA Lapatinib NA 180% Propafenone NA 60-270% Quinidine 100% NA Ranolazine 50% NA Ritonavir NA 86% Telaprevir 50% 85% Tetracycline 100% NA Verapamil 50-75% NA Digoxin concentrations increased less than 50% Atorvastatin 22% 15% Carvedilol 16% 14% Measure serum digoxin concentrations before initiating concomitant drugs.
Source: FDA drug label - digoxin
[See Dosage and Administration ( 2.2 ) and Clinical Pharmacology ( 12.3 , Tables 7 and 8).] Itraconazole ↓ itraconazole * ↓ hydroxyitraconazole * Since no dose recommendation for itraconazole can be made, alternative antifungal treatment should be considered.
Source: FDA drug label - efavirenz
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
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
Other strong inhibitors of CYP3A4 (e.g., itraconazole, clarithromycin, nefazodone, troleandomycin, ritonavir, nelfinavir) would be expected to behave similarly.
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. These effects have been observed with co-administration of itraconazole (a potent CYP3A4 inhibitor). The following specific interactions have been reported: Itraconazole Co-administration of another extended release formulation of felodipine with itraconazole resulted in approximately 8-fold increase in the AUC, more than 6-fold increase in the C max , and 2-fold prolongation in the half-life of felodipine.
Source: FDA drug label - felodipine
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.
Source: FDA drug label - fluticasone propionate
The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with Fluticasone Propionate/Salmeterol MDPI is not recommended because increased systemic corticosteroid and increased cardiovascular adverse effects may occur. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with Fluticasone Propionate/Salmeterol MDPI is not recommended because increased systemic corticosteroid and increased cardiovascular adverse effects may occur.
Source: FDA drug label - fluticasone propionate and salmeterol
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
In the same study, gemfibrozil (600 mg twice daily for 3 days) + itraconazole (200 mg in the morning and 100 mg in the evening at Day 1, then 100 mg twice daily at Day 2–3) resulted in a 19.4-(range 12.9- to 24.7-fold) higher repaglinide AUC and a 70.4 fold (range 42.9-to 119.2-fold) higher repaglinide plasma concentration 7 hours after the dose. In addition, gemfibrozil alone or gemfibrozil + itraconazole prolonged the hypoglycemic effects of repaglinide.
Source: FDA drug label - gemfibrozil
Examples include: CYP3A4 inhibitors - alprazolam; itraconazole, ketoconazole, nefazodone, ritonavir.
Source: FDA drug label - haloperidol decanoate
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
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
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
Co-administration of other strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin, cobicistat-containing products) with triamcinolone acetonide injectable suspension may cause increased plasma concentration of triamcinolone leading to adverse reactions (see ADVERSE REACTIONS ).
Source: FDA drug label - lidocaine hydrochloride, triamcinolone acetonide, povidone-iodine
Drug Interactions Effects of Other Drugs on Loperamide Concomitant use of loperamide hydrochloride capsules with inhibitors of CYP3A4 (e.g., itraconazole) or CYP2C8 (e.g., gemfibrozil) or inhibitors of P-glycoprotein (e.g., quinidine, ritonavir) can increase exposure to loperamide. CYP3A4 Inhibitors Itraconazole Concomitant administration of multiple doses of 100 mg itraconazole twice daily, an inhibitor of both CYP3A4 and P-glycoprotein, with a single 4 mg dose of loperamide hydrochloride increased the peak plasma concentration and the systemic exposure to loperamide by 2.9-fold and 3.8-fold, respectively. CYP3A4 and CYP2C8 Inhibitors When multiple doses of both 100 mg itraconazole and 600 mg gemfibrozil twice daily were administered with a single 4 mg dose of loperamide hydrochloride, the mean peak plasma concentration and the systemic exposure to loperamide was increased by 4.2-fold and 12.6-fold, respectively.
Source: FDA drug label - loperamide hydrochloride
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
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
Co-administration of other strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin, cobicistat-containing products) with triamcinolone acetonide injectable suspension may cause increased plasma concentration of triamcinolone leading to adverse reactions (see ADVERSE REACTIONS ).
Source: FDA drug label - marcaine, kenalog, povidone iodine
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 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
Examples itraconazole, ritonavir, nefazodone Cimetidine Clinical Impact The concomitant use of cimetidine, a CYP1A2, CYP2D6, and CYP3A inhibitor, with mirtazapine may increase the plasma concentration of mirtazapine [see Clinical Pharmacology (12.3) ].
Source: FDA drug label - mirtazapine
7 DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology ( 12.3 )] .
Source: FDA drug label - montelukast sodium
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
Other inhibitors of the cytochrome P450 3A4 enzyme system, such as antimycotic agents (e.g., itraconazole and miconazole) or macrolide antibiotics (e.g., erythromycin and clarithromycin), may alter oxybutynin mean pharmacokinetic parameters (i.e., C max and AUC).
Source: FDA drug label - oxybutynin chloride
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.
Source: FDA drug label - paricalcitol
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 which inhibit CYP 3A4 (e.g., ketoconazole, itraconazole, ritonavir, indinavir, macrolide antibiotics such as erythromycin ) have the potential to result in increased plasma concentrations of corticosteroids. Drugs which inhibit CYP 3A4 (e.g., ketoconazole, itraconazole, ritonavir, indinavir, macrolide antibiotics such as erythromycin ) have the potential to result in increased plasma concentrations of corticosteroids.
Source: FDA drug label - prednisone
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.
Source: FDA drug label - quetiapine
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.
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.
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
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
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.
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
Although specific interactions have not been studied, other CYP3A4 inhibitors, such as erythromycin, itraconazole, and grapefruit juice, would likely increase tadalafil exposure.
Source: FDA drug label - tadalafil
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
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) ] . For patients receiving ketoconazole or other potent CYP3A4 inhibitors such as itraconazole, miconazole, clarithromycin, ritonavir, the recommended dose of tolterodine tartrate extended-release capsules is 2 mg daily [see Dosage and Administration (2.3) ] .
Source: FDA drug label - tolterodine tartrate
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
Co-administration of other strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin, cobicistat-containing products) with Kenalog-40 Injection may cause increased plasma concentration of triamcinolone leading to adverse reactions.
Source: FDA drug label - triamcinolone acetonide
Strong CYP3A4 Inhibitors (e.g., itraconazole, clarithromycin, voriconazole) The concomitant use of vilazodone hydrochloride tablets and strong CYP3A4 inhibitors increased the exposure of vilazodone compared to the use of vilazodone hydrochloride tablets alone [see Clinical Pharmacology (12.3)].
Source: FDA drug label - vilazodone hydrochloride
Itraconazole Clinical Effect Both clarithromycin and itraconazole are substrates and inhibitors of CYP3A, potentially leading to a bi-directional drug interaction when administered concomitantly. Prevention or Management Patients taking itraconazole with VOQUEZNA TRIPLE PAK should be monitored closely for signs or symptoms of increased or prolonged adverse reactions associated with itraconazole and clarithromycin. 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