Mepral (Omeprazole)

Omeprazole is a proton pump inhibitor used to manage acid‑related gastrointestinal disorders.

• Gastro‑esophageal reflux disease (GERD): provides symptomatic relief by decreasing reflux of gastric acid into the esophagus.
• Peptic ulcer disease: promotes ulcer healing by maintaining a higher gastric pH.
• Helicobacter pylori eradication regimens: enhances the effectiveness of antibiotic therapy by suppressing acid secretion.
• Zollinger‑Ellison syndrome: controls excessive gastric acid production associated with gastrin‑producing tumors.

• Omeprazole irreversibly binds to the H+/K+ ATPase enzyme (the gastric proton pump) located on the secretory surface of parietal cells. By inhibiting this final step of acid secretion, it markedly reduces the volume and acidity of gastric juice, allowing the gastric environment to become less hostile and facilitating mucosal healing.

Omeprazole is generally well tolerated, but a range of adverse reactions have been reported.

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Diarrhea: loose stools that may resolve with continued therapy.
• Nausea: occasional feeling of queasiness, usually mild.
• Abdominal pain: discomfort in the upper abdomen.
• Flatulence: increased intestinal gas.
• Constipation: reduced bowel movements.

Serious or Rare Side Effects

• Severe allergic reaction (anaphylaxis): rash, swelling, difficulty breathing.
• Clostridioides difficile infection: persistent watery diarrhea, abdominal cramping.
• Low serum magnesium (hypomagnesemia): muscle weakness, irregular heartbeat.
• Liver enzyme elevation: signs of hepatic dysfunction.
• Stevens‑Johnson syndrome/toxic epidermal necrolysis: severe skin blistering and detachment.

When prescribing or dispensing Omeprazole, consider the following safety measures.

• Assess renal function: adjust use in patients with severe renal impairment.
• Monitor for drug interactions: review concomitant medications that may affect acid suppression.
• Use the lowest effective dose: limit duration to the shortest period necessary.
• Avoid in known hypersensitivity: discontinue if allergic reactions occur.
• Use caution in the elderly: increased risk of fractures and electrolyte disturbances.
• Store at room temperature: keep in the original pack, protect from moisture and direct sunlight.

Omeprazole can alter the pharmacokinetics of several co‑administered drugs.

Major Interactions (Avoid)

• Clopidogrel: reduced antiplatelet effect, increasing cardiovascular risk.
• Atazanavir (and other protease inhibitors): markedly decreased antiviral absorption.
• Ketoconazole: impaired antifungal efficacy due to reduced gastric acidity.

Moderate Interactions (Monitor Closely)

• Warfarin: potential increase in INR, requiring closer anticoagulation monitoring.
• Digoxin: increased serum levels, may necessitate dose adjustment.
• Oral contraceptives: possible reduction in hormonal efficacy, advise alternative contraception.