Loperamide: uses, dosing, side effects & brands

Clinical Trial Experience The adverse effects reported during clinical investigations of loperamide hydrochloride are difficult to distinguish from symptoms associated with the diarrheal syndrome. Adverse experiences recorded during clinical studies with loperamide hydrochloride were generally of a minor and self-limiting nature. They were more commonly observed during the treatment of chronic diarrhea. The adverse events reported are summarized irrespective of the causality assessment of the investigators. 1) Adverse events from 4 placebo-controlled studies in patients with acute diarrhea The adverse events with an incidence of 1.0% or greater, which were reported at least as often in patients on loperamide hydrochloride as on placebo, are presented in the table below. Acute Diarrhea Loperamide Hydrochloride Placebo No. of treated patients 231 236 Gastrointestinal AE% Constipation 2.6% 0.8% The adverse events with an incidence of 1.0% or greater, which were more frequently reported in patients on placebo than on loperamide hydrochloride, were: dry mouth, flatulence, abdominal cramp and colic. 2) Adverse events from 20 placebo-controlled studies in patients with chronic diarrhea The adverse events with an incidence of 1.0% or greater, which were reported at least as often in patients on loperamide hydrochloride as on placebo, are presented below in the table below. Chronic…

Loperamide hydrochloride capsules are contraindicated in: pediatric patients less than 2 years of age due to the risks of respiratory depression and serious cardiac adverse reactions (see WARNINGS ). patients with a known hypersensitivity to loperamide hydrochloride or to any of the excipients. patients with abdominal pain in the absence of diarrhea. patients with acute dysentery, which is characterized by blood in stools and high fever. patients with acute ulcerative colitis. patients with bacterial enterocolitis caused by invasive organisms including Salmonella , Shigella, and Campylobacter . patients with pseudomembranous colitis (e.g., Clostridium difficle ) associated with the use of broad-spectrum antibiotics.

Effects of Other Drugs on Loperamide Concomitant use of loperamide hydrochloride with inhibitors of CYP3A4 (e.g., itraconazole) or CYP2C8 (e.g., gemfibrozil) or inhibitors of P-glycoprotein (e.g., quinidine, ritonavir) can increase exposure to loperamide. The increased systemic exposure to loperamide may increase a risk for cardiac adverse reactions especially in patients who are taking multiple CYP enzyme inhibitors, or in patients with underlying cardiac conditions (see WARNINGS ). Monitor patients for cardiac adverse reactions. CYP3A4 Inhibitors Itraconazole Concomitant administration of multiple doses of 100 mg itraconazole twice daily, an inhibitor of both CYP3A4 and P-glycoprotein, with a single 4 mg dose of loperamide hydrochloride increased the peak plasma concentration and the systemic exposure to loperamide by 2.9-fold and 3.8-fold, respectively. CYP2C8 Inhibitors Gemfibrozil When a single 4 mg dose of loperamide hydrochloride was co-administered with 600 mg gemfibrozil, a strong inhibitor of CYP2C8, on day 3 of a 5-day treatment with gemfibrozil twice daily, the mean peak plasma concentration and the systemic exposure to loperamide was increased by 1.6-fold and 2.2-fold, respectively. CYP3A4 and CYP2C8 Inhibitors When multiple doses of both 100 mg itraconazole and 600 mg gemfibrozil twice daily were administered with a single 4 mg dose of loperamide hydrochloride, the mean peak plasma concentration and the systemic exposure to loperamide was increased by 4.2-fold and 12.6-fold, respectively. P-glycoprotein Inhibitors Concomitant administration of a 16 mg single dose of loperamide hydrochloride with a 600 mg single dose of quinidine or ritonavir, both of which are P-glycoprotein inhibitors, resulted in a 2- to 3-fold increase in loperamide plasma concentrations. Due to the potential for enhanced CNS adverse reactions when loperamide is co-administered with quinidine and with ritonavir, caution should be exercised when loperamide hydrochloride is administered at the recommended dosages (2 mg, up to 16 mg maximum daily dose) with P-glycoprotein inhibitors. Effects of Loperamide on Other Drugs Saquinavir When a single 16 mg dose of loperamide hydrochloride is coadministered with a 600 mg single dose of saquinavir, loperamide decreased saquinavir exposure by 54%, which may be of clinical relevance due to reduction of therapeutic efficacy of saquinavir. The effect of saquinavir on loperamide is of less clinical significance. Therefore, when loperamide hydrochloride is given with saquinavir, the therapeutic efficacy of saquinavir should be closely monitored.