Lansoprazole
Mechanism :
Lansoprazole inhibits the gastric H K ATPase (the proton pump) which catalyzes the exchange of H and K. It is effective in the inhibition of both basal acid secretion and stimulated acid secretion.
Indication :
- Gastric ulcer
- Duodenal ulcer
- Pathological hypersecretory conditions including Zollinger-Ellison syndrome
- Reflux esophagitis including patients with Barrett’s esophagus
- Eradication of H. pylori.
Contraindications :
In patients with known hypersensitivity to any component of the formulation.
Dosing :
1-3 mg/kg/day orally in two divided doses for 1-2 weeks.
Max: 60 mg/day. Give before meals; do not cut/crush/chew.
Adverse Effect :
Headache, diarrhea, nausea, flatulence, abdominal pain, constipation, and dry mouth.
Interaction :
Cytochrome P450: Lansoprazole does not have clinically significant interactions with other drugs metabolized by the cytochrome P450 system, such as warfarin, antipyrine, indomethacin, ibuprofen, phenytoin, propranolol, prednisone, diazepam, or clarithromycin in healthy subjects.
Theophylline: When lansoprazole was administered concomitantly with theophylline, a minor increase (10%) in the clearance of theophylline was seen.
Warfarin: increased International Normalized Ratio (INR) and prothrombin time in patients receiving proton pump inhibitors, including lansoprazole, and warfarin concomitantly. Patients treated with proton pump inhibitors and warfarin concomitantly may need to be monitored for increases in INR and prothrombin time.
Lansoprazole has also been shown to have no clinically significant interaction with amoxicillin.
Sucralfate: Absorption of the proton pump inhibitors was delayed, and their bioavailability was reduced. Therefore, proton pump inhibitors should be taken at least 30 minutes prior to sucralfate.
Lansoprazole causes a profound and long-lasting inhibition of gastric acid secretion; therefore, it is theoretically possible that lansoprazole may interfere with the absorption of drugs where gastric pH is an important determinant of bioavailability (e.g., ketoconazole, ampicillin esters, iron salts, digoxin).
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
20-50 | Dose as in normal renal function |
10-20 | Dose as in normal renal function |
<10 | Dose as in normal renal function |
Dose in Patients undergoing Renal Replacement Therapies
CAPD | Unlikely to be dialysed. Dose as in normal renal function |
HD | Not dialysed. Dose as in normal renal function |
HDF/High flux | Unknown dialysability. Dose as in normal renal function |
CAV/VVHD | Unknown dialysability, probably not removed. Dose as in normal renal function |
Hepatic Dose :
Specific recommendations for dose adjustments in hepatic impairment are not available. Consider dosage reduction in patients with severe hepatic disease.