Comparative Pharmacology
Head-to-head clinical analysis: PRILOSEC versus PRILOSEC OTC.
Peer-Reviewed Evidence
Head-to-head clinical analysis: PRILOSEC versus PRILOSEC OTC.
PRILOSEC vs PRILOSEC OTC
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Omeprazole is a proton pump inhibitor that irreversibly inhibits the H+/K+-ATPase enzyme system at the secretory surface of gastric parietal cells, thereby blocking the final step of gastric acid secretion.
Proton pump inhibitor that irreversibly inhibits the H+/K+ ATPase enzyme (proton pump) in gastric parietal cells, suppressing gastric acid secretion.
20 mg orally once daily before a meal for 4-8 weeks for GERD; for duodenal ulcer, 20 mg once daily for 4 weeks; for Zollinger-Ellison syndrome, initial dose 60 mg orally once daily, titrate up to 120 mg three times daily as needed.
20 mg orally once daily for 14 days for frequent heartburn; may repeat 14-day course every 4 months.
None Documented
None Documented
Terminal elimination half-life: 0.5–1 hour in healthy subjects (elimination phase); clinical context: acid suppression persists >24 hours due to irreversible binding to parietal cell H+/K+-ATPase.
Approximately 0.5–1 hour in healthy subjects; longer (up to 3 hours) in slow metabolizers or hepatic impairment. Clinically, the duration of acid suppression exceeds the half-life due to accumulation in parietal cell canaliculi.
Renal: ~77% as metabolites; fecal: ~20% as metabolites (biliary/fecal). Unchanged drug negligible.
Primarily hepatic metabolism; about 80% of metabolites are excreted in urine, and the remainder in feces via bile. Less than 1% of unchanged drug is excreted in urine.
Category C
Category C
Proton Pump Inhibitor
Proton Pump Inhibitor