Esomeprazole Strontium

Concomitant use not recommended. Esomeprazole substantially decreases atazanavir plasma concentrations (AUC decreased by 94%), resulting in loss of therapeutic effect and development of drug resistance.

Concomitant use not recommended. Esomeprazole substantially decreases nelfinavir serum levels (AUC decreased by 92%, Cmax by 89%), reducing therapeutic efficacy.

Drug interaction studies have shown that esomeprazole does not have any clinically significant interactions with phenytoin, quinidine, clarithromycin, or amoxicillin. 7.6 Combination Therapy with Clarithromycin Coadministration of esomeprazole, clarithromycin, and amoxicillin has resulted in increases in the plasma levels of esomeprazole and 14-hydroxyclarithromycin [ see Clinical Pharmacology (12.4) ]. Concomitant administration of clarithromycin with other drugs can lead to serious adverse reactions due to drug interactions [ see Warnings and Precautions in prescribing information for clarithromycin ].

Esomeprazole increases saquinavir concentrations significantly (AUC increased by 82%, Cmax by 75%), which may increase toxicity. Clinical and laboratory monitoring recommended; dose reduction should be considered.

Esomeprazole increases digoxin bioavailability by approximately 10% (up to 30% in some subjects), potentially increasing digoxin exposure and toxicity risk.

Like with other drugs that decrease the intragastric acidity, the absorption of drugs such as ketoconazole, atazanavir, iron salts, erlotinib, and mycophenolate mofetil (MMF) can decrease, while the absorption of drugs such as digoxin can increase during treatment with omeprazole. Antiretroviral Drugs: Use with atazanavir and nelfinavir is not recommended; if saquinavir is used with esomeprazole strontium, monitor for toxicity and consider saquinavir dose reduction (7.1) May interfere with drugs for which gastric pH affects bioavailability (e.g., ketoconazole, iron salts, erlotinib, digoxin, and mycophenolate mofetil).

Esomeprazole can reduce iron salts absorption due to effects on gastric acid secretion.

Like with other drugs that decrease the intragastric acidity, the absorption of drugs such as ketoconazole, atazanavir, iron salts, erlotinib, and mycophenolate mofetil (MMF) can decrease, while the absorption of drugs such as digoxin can increase during treatment with omeprazole. Antiretroviral Drugs: Use with atazanavir and nelfinavir is not recommended; if saquinavir is used with esomeprazole strontium, monitor for toxicity and consider saquinavir dose reduction (7.1) May interfere with drugs for which gastric pH affects bioavailability (e.g., ketoconazole, iron salts, erlotinib, digoxin, and mycophenolate mofetil).

Esomeprazole can reduce mycophenolate mofetil absorption due to effects on gastric acid secretion.

Drug interaction studies have shown that esomeprazole does not have any clinically significant interactions with phenytoin, quinidine, clarithromycin, or amoxicillin. 7.6 Combination Therapy with Clarithromycin Coadministration of esomeprazole, clarithromycin, and amoxicillin has resulted in increases in the plasma levels of esomeprazole and 14-hydroxyclarithromycin [ see Clinical Pharmacology (12.4) ].

Coadministration of esomeprazole 30 mg and diazepam, a CYP2C19 substrate, resulted in a 45% decrease in clearance of diazepam.

Omeprazole, of which esomeprazole is an enantiomer, has been reported to interact with some antiretroviral drugs. Therefore, clinical and laboratory monitoring for saquinavir toxicity is recommended during concurrent use with esomeprazole. 7.2 Drugs for Which Gastric pH Can Affect Bioavailability Due to its effects on gastric acid secretion, esomeprazole can reduce the absorption of drugs where gastric pH is an important determinant of their bioavailability.

Omeprazole, of which esomeprazole is an enantiomer, has been reported to interact with some antiretroviral drugs. Increased gastric pH during omeprazole treatment may change the absorption of the antiretroviral drug. 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.

Increased concentrations of saquinavir For other antiretroviral drugs, such as saquinavir, elevated serum levels have been reported, with an increase in AUC by 82%, in C max by 75%, and in C min by 106%, following multiple dosing of saquinavir/ritonavir (1000/100 mg) twice daily for 15 days with omeprazole 40 mg daily coadministered days 11 to 15.

Concomitant administration of esomeprazole and a combined inhibitor of CYP2C19 and CYP3A4, such as voriconazole, may result in more than doubling of the esomeprazole exposure.