Lomac-20 Drug Interactions

Omeprazole can prolong the eliminations of diazepam, warfarin and phenytoin, drugs that are metabolized by oxidation in the liver. Monitoring of patients also receiving warfarin or phenytoin is recommended and reduction of dose of phenytoin with propranolol or theophylline has been found, but interactions with other drugs also metabolised via the cytochrome P450 enzyme system cannot be excluded. No interaction with concomitantly administered antacids has been found.
Avoid concomitant use of clopidogrel and omeprazole. Coadministration of clopidogrel with 80 mg omeprazole, a proton pump inhibitor that is an inhibitor of CYP2C19, reduces the pharmacological activity of clopidogrel if given concomitantly or if given 12 hours apart.
Literature suggests that concomitant use of Proton Pump Inhibitors (PPIs) with methotrexate (primarily at high dose) may elevate and prolong serum levels of methotrexate and/or its metabolite, possibly leading to methotrexate toxicities. A temporary withdrawal of the PPI may be considered in some patients receiving treatments with high dose methotrexate.
Case reports, published population pharmacokinetic studies, and retrospective analyses suggest that concomitant administration of PPIs and methotrexate (primarily at high dose) may elevate and prolong serum levels of methotrexate and/or its metabolite hydroxymethotrexate. However, no formal drug interaction studies of methotrexate with PPIs have been conducted.