Lansoprazole

Proton Pump Inhibitor (PPI)

Generic Name

Lansoprazole

Drug Class

Proton pump inhibitor (PPI)

Indications

Gastroesophageal reflux disease (GERD)
Peptic ulcer disease (gastric and duodenal ulcers)
Helicobacter pylori eradication (combination therapy)
Zollinger–Ellison syndrome
Prevention of NSAID-induced ulcers

Dosage

Adults: 15–30 mg orally once daily before meals
Children (1–16 years): 15 mg/day (<30 kg) or 30 mg/day (≥30 kg)

Note: Dose adjustment may be required in severe hepatic impairment.

Route of Administration

Oral (capsule, orally disintegrating tablet, suspension)

Mechanism of Action

Lansoprazole irreversibly inhibits the H⁺/K⁺-ATPase enzyme in gastric parietal cells, leading to suppression of gastric acid secretion and increased gastric pH.

Common Adverse Effects

Headache
Diarrhea
Abdominal pain
Nausea
Dizziness

Serious Adverse Effects

Clostridioides difficile-associated diarrhea (rare)
Hypomagnesemia with long-term use
Bone fractures (long-term use)
Severe hypersensitivity reactions (rare)

Contraindications

Hypersensitivity to lansoprazole or other PPIs

Precautions

Use caution in hepatic impairment
Monitor magnesium levels if therapy exceeds 3 months
Avoid abrupt discontinuation after long-term use

Drug Interactions

Clopidogrel – reduced antiplatelet effect
Warfarin – monitor INR
Drugs requiring acidic pH for absorption (e.g., ketoconazole, atazanavir)

Pregnancy & Lactation

Use only if clearly needed. Limited human data available. Excreted into breast milk in small amounts.

Patient Counseling

Take 30–60 minutes before meals
Swallow capsules whole; do not crush or chew
Report persistent diarrhea or severe abdominal pain
Do not stop therapy abruptly if used long-term