Omeprazole can cause diazepam, warfarin, and phenytoin to be eliminated more slowly. When Omeprazole is added to the therapy, the amount of warfarin or phenytoin may need to be reduced. Omeprazole does not appear to interact with theophylline, propranolol, or antacids.
Omeprazole, a substituted benzimidazole, is a stomach acid secretion inhibitor. It reduces stomach acid secretion by inhibiting the enzyme system of hydrogen-potassium-adenosine triphosphatase (H+/K+ ATPase) in the gastric parietal cell. The antisecretory action begins within one hour of oral administration, with the greatest impact happening within two hours and secretion suppression lasting up to 72 hours. When the medication is stopped, secretory activity gradually recovers over 3 to 5 days.
