Lansoprazol Ciclum (Lansoprazole)

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

• Gastro‑esophageal reflux disease (GERD): reduces reflux symptoms and promotes healing of esophageal erosion.
• Peptic ulcer disease: facilitates ulcer healing by lowering gastric acidity.
• Helicobacter pylori eradication: enhances the effectiveness of antibiotic regimens by suppressing acid.
• Zollinger‑Ellison syndrome: controls excessive gastric acid secretion associated with gastrin‑producing tumors.

• 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 decreases basal and stimulated gastric acid secretion, leading to an increase in gastric pH. The inhibition persists until new enzyme molecules are synthesized, providing prolonged acid suppression with once‑daily dosing in most patients.

Lansoprazole may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Headache: mild pain often occurring at treatment onset.
• Diarrhea: loose stools that usually resolve with continued therapy.
• Nausea: feeling of sickness or urge to vomit.
• Abdominal pain: discomfort in the stomach area.
• Flatulence: increased intestinal gas.
• Constipation: difficulty passing stools.

Serious or Rare Side Effects

• Severe allergic reaction (anaphylaxis): swelling, rash, difficulty breathing.
• Clostridioides difficile infection: severe colitis presenting with watery diarrhea.
• Low serum magnesium (hypomagnesemia): muscle cramps, irregular heartbeat.
• Elevated liver enzymes: possible indication of hepatic stress.
• Stevens‑Johnson syndrome or toxic epidermal necrolysis: extensive skin blistering.
• Pancreatitis: acute abdominal pain with elevated enzymes.

Before initiating lansoprazole therapy, consider the following precautions.

• Assess renal function: dose adjustment may be needed in severe impairment.
• Monitor magnesium levels: long‑term use can lead to hypomagnesemia.
• Evaluate liver disease: use with caution in patients with hepatic impairment.
• Limit duration: avoid prolonged therapy without periodic reassessment.
• Use cautiously in the elderly: increased susceptibility to fractures and infections.
• Store at ambient temperature: keep below 25 °C in the original container, protected from moisture and light.

Lansoprazole can affect the pharmacokinetics of several medicines; interactions vary in clinical significance.

Major Interactions (Avoid)

• Atazanavir: reduced antiviral absorption; avoid co‑administration.
• Nelfinavir: decreased antiretroviral levels; avoid concurrent use.
• Rilpivirine: lowered exposure leading to treatment failure; avoid together.
• Clopidogrel: impaired activation, reducing antiplatelet effect; avoid combination.

Moderate Interactions (Monitor Closely)

• Warfarin: enhanced anticoagulant effect; monitor INR.
• Digoxin: increased serum concentration; check levels.
• Methotrexate: reduced clearance may cause toxicity; monitor renal function.
• Ketoconazole: decreased antifungal absorption; consider alternative dosing.
• Iron salts: reduced iron uptake; separate administration by at least 2 hours.