Omevex Drug Interactions

There is a possibility of an alteration in the absorption of some medicine due to the increase in intragastric pH. Therefore, concomitant administration with omeprazole or other acid inhibitors or other antacids may reduce the gastric absorption of ketoconazole or itraconazole.
Omeprazole can prolong the elimination of medicines which are metabolised by oxidation in the liver, e.g. diazepam, warfarin (R-warfarin), and phenytoin because of the metabolism of omeprazole via the cytochrome F4502C19 (CYP2C19) in the liver.
Patients receiving warfarin or phenytoin concomitant with omeprazole, should be monitored closely as a reduction in dosages of warfarin or phenytoin may be required. It was however shown in patients on concurrent omeprazole treatment at a daily dosage of 20 mg and continuous phenytoin treatment, that the simultaneous use of these two medications did not influence the blood concentration of phenytoin. Concomitant treatment with omeprazole 20 mg daily also did not alter coagulation time in patients on long-term treatment.
The plasma concentrations of both omeprazole and clarithromycin may be increased during concomitant treatment with these medicines. But no interactions with arilin and amoxycillin have been recorded. The concomitant use of omeprazole and these antibiotics can eradicate the Helicobacter pylori.