Omeprazole Interactions

Combination Therapy with Clarithromycin and Amoxicillin Clinical Impact: Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions, including potentially fatal arrhythmias, and are contraindicated. Amoxicillin also has drug interactions. See Drug Interactions in prescribing information for amoxicillin.

Source: FDA drug label - omeprazole

Proton Pump Inhibitors: e.g., esomeprazole lansoprazole omeprazole pantoprazole rabeprazole ↓ rilpivirine Coadministration is contraindicated with EDURANT or EDURANT PED [see Contraindications (4) ] .

Source: FDA drug label - rilpivirine hydrochloride

Omeprazole or Esomeprazole Avoid concomitant use of clopidogrel with omeprazole or esomeprazole. In clinical studies, omeprazole was shown to reduce significantly the antiplatelet activity of clopidogrel when given concomitantly or 12 hours apart. A similar reduction in antiplatelet activity was observed with esomeprazole when given concomitantly with clopidogrel.

Source: FDA drug label - clopidogrel

Omeprazole or Esomeprazole Avoid concomitant use of clopidogrel with omeprazole or esomeprazole. In clinical studies, omeprazole was shown to reduce significantly the antiplatelet activity of clopidogrel when given concomitantly or 12 hours apart. A similar reduction in antiplatelet activity was observed with esomeprazole when given concomitantly with clopidogrel.

Source: FDA drug label - clopidogrel bisulfate

Proton pump inhibitor: omeprazole ↓ omeprazole ↔ darunavir When omeprazole is co-administered with darunavir/ritonavir, monitor patients for decreased efficacy of omeprazole. Consider increasing the omeprazole dose in patients whose symptoms are not well controlled; avoid use of more than 40 mg per day of omeprazole.

Source: FDA drug label - darunavir

Mild or Moderate CYP3A Inhibitors: Clotrimazole, antibiotics (e.g., erythromycin, fluconazole), calcium channel blockers (e.g., verapamil, diltiazem, nifedipine, nicardipine), amiodarone, danazol, ethinyl estradiol, cimetidine, lansoprazole and omeprazole May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation) [see Warnings and Precautions ( 5.6 , 5.11 , 5.12 )] Monitor tacrolimus whole blood trough concentrations and reduce tacrolimus dose if needed [see Dosage and Administration ( 2.2 , 2.6 ) and Clinical Pharmacology (12.3) ] .

Source: FDA drug label - tacrolimus

Mild or Moderate CYP3A Inhibitors: Clotrimazole, antibiotics (e.g., verapamil, diltiazem, nifedipine, nicardipine), amiodarone, danazol, ethinyl estradiol, cimetidine, lansoprazole and omeprazole May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation) [see Warnings and Precautions ( 5.7 , 5.10 , 5.11 )] .

Source: FDA drug label - tacrolimus extended-release capsules

Omeprazole Clinical Effect Clarithromycin concentrations in the gastric tissue and mucus were increased by concomitant administration of omeprazole [see Clinical Pharmacology (12.3) ] . Prevention or Management Avoid concomitant use of VOQUEZNA TRIPLE PAK with omeprazole.

Source: FDA drug label - vonoprazan fumarate and amoxicillin

Monitor for toxicity and consider dose reduction of saquinavir ( 7.1 ) • May interfere with drugs for which gastric pH affects bioavailability (e.g., ketoconazole, iron salts, erlotinib, ampicillin esters, and digoxin). Like with other drugs that decrease the intragastric acidity, the absorption of drugs such as ketoconazole, ampicillin esters, iron salts and erlotinib can decrease, while the absorption of drugs such as digoxin can increase during treatment with omeprazole.

Source: FDA drug label - omeprazole

Proton Pump Inhibitors: Omeprazole No Dose Adjustment Omeprazole: The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when coadministered with clarithromycin as a result of increased omeprazole exposures [see Pharmacokinetics ( 12.3 )] (see also Omeprazole under “Drugs That Affect Clarithromycin Tablets” in the table below). Saquinavir (in patients with normal renal function) Ritonavir (in patients with normal renal function) No Dose Adjustment Proton Pump Inhibitors: Omeprazole Use With Caution Omeprazole: Clarithromycin concentrations in the gastric tissue and mucus were also increased by concomitant administration of omeprazole [see Pharmacokinetics ( 12.3 )] .

Source: FDA drug label - omeprazole

Dosage adjustment of clobazam oral suspension may be necessary when co-administered with strong CYP2C19 inhibitors (e.g., fluconazole, fluvoxamine, ticlopidine) or moderate CYP2C19 inhibitors (e.g., omeprazole) [see Clinical Pharmacology ( 12.3 )].

Source: FDA drug label - clobazam

COCs Increasing the Plasma Concentrations of CYP450 Enzymes : In clinical studies, administration of a hormonal contraceptive containing EE did not lead to any increase or only to a weak increase in plasma concentrations of CYP3A4 substrates (e.g., midazolam) while plasma concentrations of CYP2C19 substrates (e.g., omeprazole and voriconazole) and CYP1A2 substrates (e.g., theophylline and tizanidine) can have a weak or moderate increase. The potential effect of DRSP on CYP2C19 activity was investigated in a clinical pharmacokinetic study using omeprazole as a marker substrate. In the study with 24 postmenopausal women [including 12 women with homozygous (wild type) CYP2C19 genotype and 12 women with heterozygous CYP2C19 genotype] the daily oral administration of 3 mg DRSP for 14 days did not affect the oral clearance of omeprazole (40 mg, single oral dose) and the CYP2C19 product 5-hydroxy omeprazole.

Source: FDA drug label - drospirenone and ethinyl estradiol

• Increased exposure of other antiretroviral drugs (e.g., saquinavir) when used concomitantly with omeprazole may increase toxicity [see Clinical Pharmacology (12.3) ]. Saquinavir: See the prescribing information for saquinavir for monitoring of potential saquinavir-related toxicities.

Source: FDA drug label - omeprazole

In addition, no dosage adjustment is necessary for substrates of CYP2D6 (e.g., dextromethorphan, fluoxetine, paroxetine, or venlafaxine), CYP2C9 (e.g., warfarin), CYP2C19 (e.g., omeprazole, warfarin, escitalopram), or CYP3A4 (e.g., dextromethorphan) when co-administered with aripiprazole.

Source: FDA drug label - aripiprazole

In addition, no dosage adjustment is necessary for substrates of CYP2D6 (e.g., dextromethorphan, fluoxetine, paroxetine, or venlafaxine), CYP2C9 (e.g., warfarin), CYP2C19 (e.g., omeprazole, warfarin, escitalopram), or CYP3A4 (e.g., dextromethorphan) when co-administered with ARISTADA.

Source: FDA drug label - aripiprazole lauroxil

7 DRUG INTERACTIONS • Atazanavir and nelfinavir: Omeprazole reduces plasma levels of atazanavir and nelfinavir. voriconazole) may raise omeprazole levels ( 7.3 ) • Tacrolimus: Omeprazole may increase serum levels of tacrolimus ( 7.4 ) • Methotrexate: Omeprazole may increase serum levels of methotrexate ( 7.7 ) 7.1 Interference with Antiretroviral Therapy Concomitant use of atazanavir and nelfinavir with proton pump inhibitors is not recommended. Co-administration of atazanavir with proton pump inhibitors is expected to substantially decrease atazanavir plasma concentrations and may result in a loss of therapeutic effect and the development of drug resistance.

Source: FDA drug label - omeprazole

7.9 Drugs that Affect Gastric pH Drugs that elevate gastric pH (magnesium hydroxide/aluminum hydroxide, omeprazole) had no effect on atomoxetine bioavailability.

Source: FDA drug label - atomoxetine

7.9 Drugs that Affect Gastric pH Drugs that elevate gastric pH (magnesium hydroxide/aluminum hydroxide, omeprazole) had no effect on atomoxetine bioavailability.

Source: FDA drug label - atomoxetine hydrochloride

7.2 Drugs Without Clinically Significant Interactions with Bortezomib No clinically significant drug interactions have been observed when bortezomib was coadministered with dexamethasone, omeprazole, or melphalan in combination with prednisone [see Clinical Pharmacology ( 12.3 )].

Source: FDA drug label - bortezomib

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

Co-administration of CYP2C19 inhibitors, such as omeprazole or fluvoxamine, with carisoprodol could result in increased exposure of carisoprodol and decreased exposure of meprobamate.

Source: FDA drug label - carisoprodol

Inhibitors of CYP2C19 Coadministration with CYP2C19 inhibitors (e.g., omeprazole) increases systemic exposure of cilostazol active metabolites.

Source: FDA drug label - cilostazol

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

7.2 Drugs Having No Clinically Important Interactions with Amphetamine From a pharmacokinetic perspective, no dose adjustment of XELSTRYM is necessary when XELSTRYM is co-administered with guanfacine, venlafaxine, or omeprazole. omeprazole, lansoprazole, clobazam), and CYP3A4 (e.g.

Source: FDA drug label - dextroamphetamine

An example of a proton pump inhibitor is omeprazole. An example of a proton pump inhibitor is omeprazole.

Source: FDA drug label - dextroamphetamine saccharate, amphetamine aspartate monohydrate, dextroamphetamine sulfate, and amphetamine sulfate

At present, this reaction is known to occur with cimetidine, ketoconazole, fluvoxamine, fluoxetine, and omeprazole.

Source: FDA drug label - omeprazole

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

7 DRUG INTERACTIONS • Atazanavir and nelfinavir: Omeprazole reduces plasma levels of atazanavir and nelfinavir. voriconazole) may raise omeprazole levels ( 7.3 ) • Tacrolimus: Omeprazole may increase serum levels of tacrolimus ( 7.4 ) • Methotrexate: Omeprazole may increase serum levels of methotrexate ( 7.7 ) 7.1 Interference with Antiretroviral Therapy Concomitant use of atazanavir and nelfinavir with proton pump inhibitors is not recommended. Reduced concentrations of atazanavir and nelfinavir For some antiretroviral drugs, such as atazanavir and nelfinavir, decreased serum levels have been reported when given together with omeprazole.

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

7.2 CYP2C19 Substrates Eslicarbazepine acetate can inhibit CYP2C19, which can cause increased plasma concentrations of drugs that are metabolized by this isoenzyme (e.g., phenytoin, clobazam, and omeprazole) [see Clinical Pharmacology ( 12.3 )] .

Source: FDA drug label - eslicarbazepine acetate

7 DRUG INTERACTIONS Tables 3 and 4 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with esomeprazole and instructions for preventing or managing them. Table 3: Clinically Relevant Interactions Affecting Drugs Co-Administered with Esomeprazole and Interaction with Diagnostics Antiretrovirals Clinical Impact: The effect of PPIs on antiretroviral drugs is variable. Decreased exposure of some antiretroviral drugs (e.g., rilpivirine atazanavir, and nelfinavir) when used concomitantly with esomeprazole may reduce antiviral effect and promote the development of drug resistance [see Clinical Pharmacology (12.3) ].

Source: FDA drug label - esomeprazole magnesium

7.4 Drugs Without Clinically Significant Interactions with Etravirine Tablets In addition to the drugs included in Table 4, the interaction between etravirine tablets and the following drugs were evaluated in clinical studies and no dose adjustment is needed for either drug [see Clinical Pharmacology (12.3) ] : didanosine, enfuvirtide (ENF), ethinylestradiol/norethindrone, omeprazole, paroxetine, raltegravir, ranitidine, and tenofovir disoproxil fumarate. 7.4 Drugs Without Clinically Significant Interactions with Etravirine Tablets In addition to the drugs included in Table 4, the interaction between etravirine tablets and the following drugs were evaluated in clinical studies and no dose adjustment is needed for either drug [see Clinical Pharmacology (12.3) ] : didanosine, enfuvirtide (ENF), ethinylestradiol/norethindrone, omeprazole, paroxetine, raltegravir, ranitidine, and tenofovir disoproxil fumarate.

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.

Source: FDA drug label - extended phenytoin sodium

Based on a finding of substantial interactions of fluvoxamine with certain of these drugs (see later parts of this section and also WARNINGS AND PRECAUTIONS [ 5 ] for details) and limited in vitro data for CYP3A4, it appears that fluvoxamine inhibits several cytochrome P450 isoenzymes that are known to be involved in the metabolism of other drugs such as: CYP1A2 (e.g., warfarin, theophylline, propranolol, tizanidine), CYP2C9 (e.g., warfarin), CYP3A4 (e.g., alprazolam), and CYP2C19 (e.g., omeprazole). A clinically significant fluvoxamine interaction is possible with drugs having a narrow therapeutic ratio such as pimozide, warfarin, theophylline, certain benzodiazepines, omeprazole, and phenytoin.

Source: FDA drug label - fluvoxamine maleate

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

7.2 Drugs Having No Clinically Important Interactions with Lisdexamfetamine Dimesylate Capsules From a pharmacokinetic perspective, no dose adjustment of lisdexamfetamine dimesylate capsules is necessary when lisdexamfetamine dimesylate capsules is co-administered with guanfacine, venlafaxine, or omeprazole. From a pharmacokinetic perspective, no dose adjustment for drugs that are substrates of CYP1A2 (e.g., theophylline, duloxetine, melatonin), CYP2D6 (e.g., atomoxetine, desipramine, venlafaxine), CYP2C19 (e.g., omeprazole, lansoprazole, clobazam), and CYP3A4 (e.g., midazolam, pimozide, simvastatin) is necessary when VYVANSE is co-administered [see Clinical Pharmacology (12.3) ] .

Source: FDA drug label - lisdexamfetamine dimesylate

7.4 Drugs with No Observed or Predicted Interactions with Lopinavir And Ritonavir Drug interaction or clinical studies reveal no clinically significant interaction between lopinavir and ritonavir and desipramine (CYP2D6 probe), etravirine, pitavastatin, pravastatin, stavudine, lamivudine, omeprazole, raltegravir, ranitidine, or rilpivirine.

Source: FDA drug label - lopinavir and ritonavir

Effects of Modafinil on CYP2C19 Substrates Elimination of drugs that are substrates for CYP2C19 (e.g., phenytoin, diazepam, propranolol, omeprazole, and clomipramine) may be prolonged by modafinil via inhibition of metabolic enzymes, with resultant higher systemic exposure. ( 7 ) • CYP2C19 substrates, such as omeprazole, phenytoin, and diazepam: Exposure of these medications may be increased.

Source: FDA drug label - modafinil

7 DRUG INTERACTIONS See Table 3 and Table 4 for clinically significant drug interactions and interactions with diagnostics with naproxen and esomeprazole magnesium. Table 3: Clinically Significant Drug Interactions with Naproxen and Esomeprazole Magnesium – Affecting Drugs Co-Administered with Naproxen and Esomeprazole magnesium delayed-release tablets and Interactions with Diagnostics Clinical Impact: Naproxen • Naproxen and anticoagulants such as warfarin have a synergistic effect on bleeding. Esomeprazole Magnesium • Increased INR and prothrombin time in patients treated with PPIs, including esomeprazole, and warfarin concomitantly.

Source: FDA drug label - naproxen and esomeprazole magnesium

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

Inducers of CYP1A2 or Glucuronyl Transferase — Omeprazole and rifampin may cause an increase in olanzapine clearance.

Source: FDA drug label - olanzapine

Inducers of CYP1A2 or Glucuronyl Transferase Enzymes — Omeprazole and rifampin may cause an increase in olanzapine clearance.

Source: FDA drug label - olanzapine pamoate

7 DRUG INTERACTIONS Tables 6 and 7 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with omeprazole and instructions for preventing or managing them. Table 6: Clinically Relevant Interactions Affecting Drugs Co-Administered with Omeprazole and Interaction with Diagnostics Antiretrovirals Clinical Impact: The effect of PPIs on antiretroviral drugs is variable. Decreased exposure of some antiretroviral drugs (e.g., rilpivirine, atazanavir and nelfinavir) when used concomitantly with omeprazole may reduce antiviral effect and promote the development of drug resistance [see Clinical Pharmacology (12.3) ] .

Source: FDA drug label - omeprazole, sodium bicarbonate

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.

Source: FDA drug label - phenytoin

While no formal drug interaction studies have been performed, the following concomitant drugs were used in at least 10% of patients in either or both Sjogren's efficacy studies: acetylsalicylic acid, artificial tears, calcium, conjugated estrogens, hydroxychloroquine sulfate, ibuprofen, levothyroxine sodium, medroxyprogesterone acetate, methotrexate, multivitamins, naproxen, omeprazole, paracetamol, and prednisone.

Source: FDA drug label - pilocarpine hydrchloride

While no formal drug interaction studies have been performed, the following concomitant drugs were used in at least 10% of patients in either or both Sjogren's efficacy studies: acetylsalicylic acid, artificial tears, calcium, conjugated estrogens, hydroxychloroquine sulfate, ibuprofen, levothyroxine sodium, medroxyprogesterone acetate, methotrexate, multivitamins, naproxen, omeprazole, paracetamol, and prednisone.

Source: FDA drug label - pilocarpine hydrochloride

Although in normal subjects no interaction with theophylline or propranolol was found, there have been clinical reports of interaction with other drugs metabolized via the cytochrome P450 system (e.g., cyclosporine, disulfiram, benzodiazepines).

Source: FDA drug label - omeprazole

No interaction was observed with omeprazole. No interaction was observed with omeprazole.

Source: FDA drug label - propranolol hydrochloride

This degree of inhibition is similar to that by omeprazole at equivalent concentrations.

Source: FDA drug label - rabeprazole sodium

Ritonavir-containing products: see prescribing information for specific drugs.

Source: FDA drug label - omeprazole

Proton-pump inhibitors (e.g., omeprazole) Omeprazole 20 mg can be administered with VOSEVI.

Source: FDA drug label - sofosbuvir, velpatasvir, and voxilaprevir

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

A phenotypic cocktail study was conducted with 16 healthy volunteers to quantify the influence of 10 days of APTIVUS/ritonavir capsule administration on the activity of hepatic CYP1A2 (caffeine), 2C9 (warfarin), 2C19 (omeprazole), 2D6 (dextromethorphan) and the activity of intestinal and hepatic CYP3A4/5 (midazolam) and P-glycoprotein (P-gp) (digoxin). Proton Pump Inhibitors: Omeprazole ↓ Omeprazole, ↔ Tipranavir Dosage of omeprazole may need to be increased when co-administered with APTIVUS and ritonavir.

Source: FDA drug label - tipranavir

In vivo studies with omeprazole, metabolized by CYP2C19 and CYP3A4, and simvastatin, metabolized by CYP3A4, showed up to a 28% and 57% decrease in exposure one week following a single dose of tocilizumab, respectively.

Source: FDA drug label - tocilizumab

7.4 Other Drugs Metabolized by Cytochrome P450 Isoenzymes In vivo drug-interaction data show that tolterodine immediate release does not result in clinically relevant inhibition of CYP1A2, 2D6, 2C9, 2C19, or 3A4 as evidenced by lack of influence on the marker drugs caffeine, debrisoquine, S-warfarin, and omeprazole [see Clinical Pharmacology (12.3) ] . In vivo drug-interaction data show that tolterodine immediate release does not result in clinically relevant inhibition of CYP1A2, 2D6, 2C9, 2C19, or 3A4 as evidenced by lack of influence on the marker drugs caffeine, debrisoquine, S-warfarin, and omeprazole.

Source: FDA drug label - tolterodine tartrate

Intervention: Voriconazole: Dose adjustment of omeprazole is not normally required. See prescribing information for voriconazole.

Source: FDA drug label - omeprazole

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