I have taken Omeprazole for many years, but I don't like taking unnecessary tablets and drugs. I researched information about it from reputable sources and wrote this to gain a deeper understanding of it and its functions.
Introduction.
Omeprazole is a benzimidazole PPI, first approved in 1988 and widely used to reduce gastric acid secretion. It is available by prescription and over-the-counter under brand names such as Prilosecยฎ and Losecยฎ.
Mechanism of Action.
As a prodrug, omeprazole accumulates in the acidic canaliculi of gastric parietal cells. There it is converted to its active sulfenamide form, which irreversibly inhibits the Hโบ/Kโบ-ATPase enzyme (โproton pumpโ), blocking the final step of acid production.
Medical Uses.
Omeprazole treats a range of acid-related disorders, including:
- Gastroesophageal reflux disease (GERD) and erosive esophagitis.
- Peptic ulcer disease (gastric and duodenal ulcers).
- ZollingerโEllison syndrome and other pathological hypersecretory conditions.
- Helicobacter pylori eradication in combination with antibiotics to promote ulcer healing and reduce recurrence.
Over-the-counter omeprazole (20 mg) is approved for adults with frequent heartburn (โฅ2 days/week) as a 14-day continuous course.
Dosage and Administration.
- Adults: 20โ40 mg once daily, taken 30โ60 minutes before a meal.
- H. pylori eradication: 20 mg twice daily for 10โ14 days, combined with clarithromycin and amoxicillin or metronidazole.
- Hypersecretory states (e.g., ZollingerโEllison): Doses up to 240 mg/day in divided doses under specialist supervision.
- Special Populations: Pediatric, elderly, and hepatic-impaired patients require individualised dosing and monitoring by a healthcare provider.
Side Effects and Long-Term Risks.
- Common (โฅ1%): Headache, abdominal pain, nausea, diarrhoea, flatulence, constipation.
- Severe (rare): Clostridioides difficile infection, acute interstitial nephritis, subacute cutaneous lupus erythematosus, bone fractures with long-term use.
- Long-term (โฅ1 year): Hypomagnesemia, vitamin Bโโ deficiency, osteoporosis-related fractures, possible renal impairment, dementia, and marginally increased stomach cancer risk in observational studies.
Drug Interactions.
Omeprazole is metabolised primarily by CYP2C19 and CYP3A4. Potential interactions include reduced efficacy of clopidogrel and altered absorption of drugs requiring acidic pH (e.g., ketoconazole, atazanavir). A complete medication review is recommended when initiating therapy.
Warnings and Precautions.
- Hypersensitivity: Contraindicated in patients with known allergy to omeprazole or other PPIs.
- Laboratory Monitoring: Periodic checks of magnesium, calcium, and vitamin Bโโ levels during prolonged therapy.
- Rebound Acid Hypersecretion: Taper dose rather than abrupt discontinuation after long-term use.
- Delayed Onset: Not for immediate relief of acute heartburn; full effect may take 1โ4 days.
Conclusion.
Omeprazole remains a foundational therapy for acid-related gastrointestinal conditions due to its proven efficacy and generally favourable safety profile. Optimal use involvesย selecting patients appropriately, administering the correct dose at the right time, monitoring for adverse effects, and regularly reassessing the ongoing need.
Helpful video about PPI.
This video is from The Stealth Doctors YouTube channel.
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