Prilosec

Prilosec
Name	Prilosec
Tradename	Prilosec
Generic name	omeprazole
Routes of administration	Oral
Class	Proton pump inhibitor
Legal status	Rx/OTC
Metabolism	Hepatic (CYP2C19, CYP3A4)
Elimination half-life	0.5–1 hour (acid-inhibited effect longer)
Excretion	Renal, fecal

Prilosec is the brand name for omeprazole, a proton pump inhibitor used to reduce gastric acid secretion. It is employed in the management of acid-related disorders and has been widely studied in clinical trials and guideline recommendations. Major manufacturers, regulatory agencies, and clinical organizations have influenced its adoption worldwide.

Medical uses

Prilosec is indicated for treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and eradication regimens for Helicobacter pylori when combined with antibiotics. It is used for healing of erosive esophagitis and maintenance therapy to prevent recurrence, and for Zollinger–Ellison syndrome associated with acid hypersecretion. Clinical practice guidelines from organizations such as the American Gastroenterological Association, American College of Gastroenterology, National Institute for Health and Care Excellence, and specialty societies inform its use in pediatric, adult, and geriatric populations.

Mechanism of action

Prilosec inhibits the H+/K+ ATPase enzyme (the gastric proton pump) on parietal cells in the stomach, leading to profound and long-lasting reduction in gastric acid secretion. The drug is a substituted benzimidazole that requires activation in acidic compartments; biochemical characterization was advanced by research groups at institutions like the National Institutes of Health, University of California, San Francisco, and pharmaceutical laboratories including AstraZeneca. Pharmacodynamic studies referenced by bodies such as the Food and Drug Administration and European Medicines Agency document its onset, duration, and effects on intragastric pH.

Dosage and administration

Prilosec is available as delayed-release capsules or tablets, typically administered once daily before meals for GERD or peptic ulcer disease; higher or divided doses may be used for Zollinger–Ellison syndrome under specialist supervision. Over-the-counter formulations and prescription strengths differ; dosing recommendations appear in monographs from regulators including the United States Pharmacopeia, European Pharmacopoeia, and national formularies such as the British National Formulary and the Canadian Pharmacists Association. Special population guidance from the World Health Organization and pediatric/geriatric guidance from national health services should be consulted for dose adjustments.

Side effects and contraindications

Common adverse effects include headache, abdominal pain, nausea, diarrhea, and constipation; less common events include vitamin B12 deficiency with long-term use and increased risk of community-acquired pneumonia. Serious but rare effects reported to regulatory authorities such as the Food and Drug Administration and European Medicines Agency include interstitial nephritis, Clostridioides difficile infection, and bone fracture risk with chronic high-dose therapy. Contraindications include known hypersensitivity to omeprazole or substituted benzimidazoles; clinical decision-making often references consensus statements from the American Society of Health-System Pharmacists and specialty guideline panels.

Interactions

Prilosec is metabolized primarily by cytochrome P450 enzymes, notably CYP2C19 and CYP3A4, leading to clinically relevant interactions with drugs such as clopidogrel, warfarin, diazepam, and certain antifungals and antiretrovirals. Interaction alerts are included in prescribing information issued by the Food and Drug Administration, the European Medicines Agency, and electronic drug databases used by institutions like Mayo Clinic and Cleveland Clinic. Genetic polymorphisms in CYP2C19, studied in cohorts at institutions including Johns Hopkins University and Massachusetts General Hospital, influence metabolic phenotype and may affect therapeutic response and interaction risk.

Pharmacokinetics

Following oral administration, Prilosec is absorbed and converted to its active sulfenamide form in the acidic canaliculi of parietal cells; it exhibits a short plasma half-life but sustained acid suppression due to irreversible pump inhibition. Hepatic metabolism via CYP2C19 and CYP3A4 yields metabolites excreted in urine and feces; pharmacogenetic variability and hepatic impairment alter clearance. Regulatory pharmacokinetic studies submitted to agencies such as the Food and Drug Administration and academic pharmacology departments have characterized bioavailability, protein binding, and effects of food and coadministered agents.

History and regulatory status

Prilosec was developed in the late 1970s and 1980s by teams at AstraZeneca and predecessor companies, emerging from medicinal chemistry efforts on substituted benzimidazoles. Approval milestones include regulatory authorizations by the Food and Drug Administration and marketing approvals across Europe and other regions; patent litigation and generic entry involved companies such as Teva Pharmaceutical Industries, Mylan, and Novartis. Over time, safety reviews, labeling changes, and over-the-counter switches were overseen by authorities including the European Medicines Agency and national regulators, with ongoing pharmacovigilance coordinated by networks like the WHO Programme for International Drug Monitoring.

Category:Proton pump inhibitors Category:Omeprazole