Omeprazole Magnesium

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.

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. Intervention: See Contraindications , Warnings and Precautions in prescribing information for clarithromycin.

Concomitant use with omeprazole is contraindicated due to decreased antiretroviral exposure that may reduce antiviral effect and promote drug resistance.

• 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 )]. Atazanavir : Avoid concomitant use with PRILOSEC. See prescribing information for atazanavir for dosing information.

Omeprazole 80 mg results in reduced plasma concentrations of clopidogrel's active metabolite and reduced platelet inhibition.

Concomitant use, especially at high dose, may elevate and prolong serum concentrations of methotrexate and hydroxymethotrexate, possibly leading to methotrexate toxicities.

• 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 )]. Nelfinavir : Avoid concomitant use with PRILOSEC. See prescribing information for nelfinavir.

Increased exposure when used concomitantly with omeprazole may increase toxicity. Monitor for potential saquinavir-related toxicities.

Concomitant use may increase INR and prothrombin time, leading to abnormal bleeding and potentially death. Monitor INR and adjust warfarin dose as needed.

CYP2C19 substrate; concomitant use with omeprazole may alter cilostazol concentrations.

CYP2C19 substrate; concomitant use with omeprazole may alter citalopram concentrations.

CYP2C19 Substrates (e.g., clopidogrel, citalopram, cilostazol, phenytoin, diazepam) Clopidogrel Clinical Impact: Concomitant use of omeprazole 80 mg results in reduced plasma concentrations of the active metabolite of clopidogrel and a reduction in platelet inhibition [see Clinical Pharmacology ( 12.3 )]. Diazepam Clinical Impact: Increased exposure of diazepam [see Clinical Pharmacology ( 12.3 )] . Intervention: Monitor patients for increased sedation and reduce the dose of diazepam as needed.

CYP2C19 substrate; concomitant use with omeprazole may alter phenytoin concentrations.

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.

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.

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.

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.

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.

7 DRUG INTERACTIONS Table 3 and Table 4 include drugs with clinically important drug interactions and interaction with diagnostics when administered concomitantly with omeprazole and instructions for preventing or managing them. Table 3: 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 )].

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

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