Lansoprazole is used short-term (4-8 weeks) to treat duodenal ulcer and erosive esophagitis. It may used long term to treat Zollinger-Ellison syndrome, a problem with too much acid being secreted. Lansoprazole capsules should be taken before eating. The capsules are delayed release meaning they work over time. The capsules should be swallowed whole and not crushed, opened or chewed. If you are taking theophylline, you may need your dosage checked when you start and stop lansoprazole to ensure your dose is effective. If you are taking sucralfate, it should be taken 30 minutes after taking lansoprazole. The most common side effects reported were diarrhea, nausea and abdominal pain. These occurred in fewer than 5% of patients. If your symptoms return after completing your course of therapy, talk to your physician for further evaluation.
Lansoprazole is metabolized through the cytochrome P450 system, specifically through the CYP3A and CYP2C19 isozymes. Studies have shown that 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, clarithromycin, or terfenadine in healthy subjects. These compounds are metabolized through various cytochrome P450 isozymes including CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A. When lansoprazole was administered concomitantly with theophylline (CYP1A2, CYP3A), a minor increase (10%) in the clearance of theophylline was seen. Because the small magnitude and the direction of the effect on theophylline clearance, this interaction is unlikely to be clinical concern. Nonetheless, individual patients may require additional titration of their theophylline dosage when lansoprazole is started or stopped to ensure clinically effective blood levels.
Lansoprazole has also been shown to have no clinically significant interaction with amoxicillin.
In a single-dose crossover study examining lansoprazole 30 mg and omeprazole 20 mg each administered alone and concomitantly with sucralfate 1 gram, absorption of the proton pump inhibitors was delayed and their bioavailability was reduced by 17% and 16%, respectively, when administered concomitantly with sucralfate. Therefore, proton pump inhibitors should be taken at least 30 minutes prior to sucralfate. In clinical trials, antacids were administered concomitantly with lansoprazole delayed-release capsules; this did not interfere with its effect.
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).
Lansoprazole is contraindicated in patients with known hypersensitivity to any component of the formulation.
Lansoprazole delayed-release capsules are contraindicated in patients with known hypersensitivity to any component of the formulation.
Amoxicillin is contraindicated in patients with a known hypersensitivity to any penicillin. (Please refer to full prescribing information for amoxicillin before prescribing.)
Clarithromycin is contraindicated in patients with a known hypersensitivity to any macrolide antibiotic, and in patients receiving terfenadine therapy who have preexisting cardiac abnormalities or electrolyte disturbances. (Please refer to clarithromycin before prescribing.)