Nexium (Esomeprazole Magnesium Trihydrate)

Nexium, a proton pump inhibitor, is used to manage disorders associated with excess gastric acid secretion.

• Gastro‑oesophageal reflux disease (GERD): alleviates heartburn and regurgitation by maintaining a higher gastric pH.
• Erosive oesophagitis: promotes healing of acid‑damaged esophageal tissue.
• Zollinger‑Ellison syndrome: controls hyper‑secretion of gastric acid caused by gastrin‑producing tumors.
• NSAID‑induced gastric ulcer: reduces ulcer formation in patients taking non‑steroidal anti‑inflammatory drugs.
• Helicobacter pylori eradication (as part of combination therapy): enhances the effectiveness of antibiotic regimens by suppressing acid.

• Esomeprazole 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 production, it markedly reduces both basal and stimulated gastric acid secretion, leading to an increased gastric pH and allowing damaged mucosa to heal.

Adverse reactions may occur with any medication and should be monitored by a healthcare professional.

Common Side Effects

• Headache: mild to moderate pain in the head region.
• Diarrhoea: loose, watery stools occurring intermittently.
• Nausea: sensation of unease and urge to vomit.
• Abdominal pain: discomfort or cramping in the stomach area.
• Flatulence: excess gas causing bloating.
• Constipation: difficulty passing stools.

Serious or Rare Side Effects

• Severe allergic reaction: rash, itching, swelling, or difficulty breathing.
• Clostridioides difficile infection: persistent diarrhoea with abdominal pain.
• Low magnesium levels: muscle cramps, irregular heartbeat, or seizures.
• Bone fractures: increased risk with long‑term use.
• Liver enzyme elevation: abnormal blood test results indicating hepatic stress.

Before initiating therapy, consider the following safety measures.

• Assess renal function: dose adjustment may be needed in severe impairment.
• Evaluate hepatic status: monitor liver enzymes in patients with liver disease.
• Review concomitant medications: avoid drugs that require gastric acidity for absorption.
• Long‑term use caution: consider bone health monitoring for osteoporosis risk.
• Pregnancy and lactation: use only if clearly needed after risk‑benefit assessment.
• Store at ambient temperature: keep below 25°C in the original container, protect from moisture and light.

Esomeprazole may affect the pharmacokinetics of several co‑administered drugs.

Major Interactions (Avoid)

• Ketoconazole or itraconazole: reduced antifungal absorption leading to therapeutic failure.
• Atazanavir: markedly decreased plasma concentrations, compromising HIV treatment.
• Clopidogrel: diminished activation, potentially reducing antiplatelet effect.

Moderate Interactions (Monitor Closely)

• Warfarin: possible increase in INR, requiring closer coagulation monitoring.
• Digoxin: elevated serum levels may occur, necessitating dose adjustment.
• Methotrexate (high dose): increased toxicity risk, monitor renal function and blood counts.