Lanso (Lansoprazole)

Lansoprazole is indicated for several acid‑related gastrointestinal conditions.

• Gastro‑oesophageal reflux disease (GERD): reduces reflux symptoms and promotes healing of esophageal erosion.
• Peptic ulcer disease: facilitates ulcer healing and prevents recurrence.
• Helicobacter pylori eradication (in combination therapy): enhances the effectiveness of antibiotic regimens.
• Zollinger‑Ellison syndrome: controls excessive gastric acid secretion.

• Lansoprazole 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 lowers both basal and stimulated gastric acidity, allowing ulcer healing and symptom relief. The inhibition is sustained for up to 72 hours because new enzyme synthesis is required for acid secretion to resume, providing prolonged acid control after each dose.

Lansoprazole may cause a range of adverse reactions, most of which are mild, transient, and dose‑independent.

Common Side Effects

• Headache: mild to moderate headache that usually resolves without treatment.
• Diarrhea: loose, watery stools that may occur during the first weeks of therapy.
• Nausea: transient feeling of sickness, often mild and self‑limiting.
• Abdominal discomfort: mild stomach pain or cramping.
• Flatulence: increased gas leading to bloating.

Serious or Rare Side Effects

• Clostridioides difficile infection: severe colitis that can develop after prolonged acid suppression.
• Acute interstitial nephritis: inflammation of the kidney interstitium presenting with fever, rash, and impaired renal function.
• Stevens‑Johnson syndrome: rare, life‑threatening skin reaction characterized by blistering and mucosal involvement.

When prescribing Lansoprazole, several precautions should be considered to ensure safe use.

• Assess renal function: adjust therapy in patients with severe renal impairment.
• Monitor for Clostridioides difficile infection: be vigilant for persistent diarrhea.
• Evaluate hepatic status: use with caution in moderate to severe liver disease.
• Review concomitant clopidogrel therapy: consider alternative antiplatelet agents due to reduced activation.
• Avoid abrupt discontinuation: taper the dose to prevent rebound acid hypersecretion.
• Store at room temperature: keep in the original container, protect from moisture and light.

Lansoprazole can affect the pharmacokinetics of several medicines, requiring attention to potential interactions.

Major Interactions (Avoid)

• Ketoconazole: reduced absorption due to increased gastric pH.
• Atazanavir: markedly decreased plasma concentrations, compromising antiviral efficacy.
• Clopidogrel: diminished conversion to active metabolite, reducing antiplatelet effect.

Moderate Interactions (Monitor Closely)

• Warfarin: possible increase in INR, requiring closer coagulation monitoring.
• Digoxin: modest increase in serum levels, may need dose adjustment.
• Methotrexate: increased exposure, especially at high doses, monitor for toxicity.