Overview
Lansoprazole is a proton pump inhibitor that suppresses gastric acid secretion by inhibiting the H+/K+ ATPase enzyme system at the secretory surface of gastric parietal cells. It is used for treating conditions like gastroesophageal reflux disease (GERD), erosive esophagitis, and Helicobacter pylori infection. The drug provides symptomatic relief and promotes healing of acid-related damage to the esophagus and stomach.
Mechanism of Action
Lansoprazole is a proton pump inhibitor that suppresses gastric acid secretion by specifically inhibiting the H+/K+ ATPase enzyme system at the secretory surface of gastric parietal cells. This inhibition is dose-dependent and effectively reduces both basal and stimulated acid production.
Indications
- Treatment of active duodenal ulcer
- Maintenance of healed duodenal ulcers
- Treatment of active benign gastric ulcer
- Healing of erosive esophagitis
- Maintenance of healing of erosive esophagitis
- Treatment of symptomatic gastroesophageal reflux disease (GERD)
- Healing of NSAID-associated gastric ulcers
- Risk reduction of NSAID-associated gastric ulcers
- Treatment of pathological hypersecretory conditions including Zollinger-Ellison syndrome
- Helicobacter pylori eradication in combination with antibiotics
Common Doses
- 15 mg
- 30 mg
Dosage
Typical adult dosage is 15-30 mg once daily before eating. For H. pylori eradication, lansoprazole is combined with antibiotics (usually clarithromycin and amoxicillin) in specific regimens. Dosage adjustments may be needed for hepatic impairment. The delayed-release capsules should be swallowed whole and not chewed or crushed.
Contraindications
- Known hypersensitivity to any component of lansoprazole formulation
- Concomitant use with rilpivirine-containing products
Side Effects
- Headache
- Diarrhea
- Abdominal pain
- Nausea
- Constipation
- Dizziness
- Rash
- Acute tubulointerstitial nephritis
- Clostridium difficile-associated diarrhea
- Bone fractures
- Severe cutaneous adverse reactions
- Hypomagnesemia
- Vitamin B12 deficiency
Interactions
- Rilpivirine: Contraindicated
- Atazanavir: Decreased exposure, adjust dosing
- Warfarin: Increased INR, monitor closely
- Methotrexate: Increased concentrations, consider temporary withdrawal
- Digoxin: Increased exposure, monitor concentrations
- Theophylline: Increased clearance, may need dosage adjustment
- Drugs dependent on gastric pH for absorption (iron salts, erlotinib, dasatinib, etc.): Reduced absorption
- Tacrolimus: Increased exposure, monitor concentrations
- Clarithromycin/amoxicillin: See specific contraindications and warnings
- CYP2C19/CYP3A4 inducers: Decreased lansoprazole exposure
- Sucralfate: Decreased lansoprazole absorption, administer 30 minutes apart
Counseling Points
- Take once daily before eating, preferably in the morning
- Swallow capsules whole; do not chew, crush, or split
- Report severe diarrhea, abdominal pain, or signs of kidney problems
- Long-term use may increase risk of bone fractures; discuss calcium and vitamin D supplementation
- Report any new or worsening symptoms of lupus
- Inform healthcare provider of all medications being taken
- Be aware of potential false positive urine THC tests