LOPERAMIDE HYDROCHLORIDE

Loperamide hydrochloride, 4-(p-chlorophenyl)-4-hydroxy-N,N-dimethyl- a,a- diphenyl-1-piperidinebutyramide monohydrochloride, is a synthetic antidiarrheal for oral use. Loperamide hydrochloride capsules, USP are available in 2 mg capsules for oral administration. The inactive ingredients are: corn starch, lactose monohydrate, magnesium stearate and talc. The capsule shell contains gelatin, iron oxide red, iron oxide yellow and sodium lauryl sulfate. The capsules are imprinted with black ink containing black iron oxide, potassium hydroxide, propylene glycol and shellac. FDA approved dissolution test specifications differ from USP. str

Loperamide hydrochloride capsules are indicated for the control and symptomatic relief of acute nonspecific diarrhea in patients 2 years of age and older and of chronic diarrhea in adults associated with inflammatory bowel disease. Loperamide hydrochloride capsules are also indicated for reducing the volume of discharge from ileostomies.

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 CONTRAINDICATIONS ). Avoid loperamide hydrochloride capsule dosages higher than recommended in adult or pediatric patients 2 years of age and older due to the risk of serious cardiac adverse reactions (See WARNINGS , OVERDOSAGE ). (1 capsule = 2 mg) Patients should receive appropriate fluid and electrolyte replacement as needed. Acute Diarrhea Adults and Pediatric Patients 13 Years and Older: The recommended initial dose is 4 mg (two capsules) followed by 2 mg (one capsule) after each unformed stool. The maximum daily dose is 16 mg (eight capsules). Clinical improvement is usually observed within 48 hours. Pediatric Patients 2 Years to 12 Years of Age : In pediatric patients 2 years to 5 years of age (20 kg or less), the non-prescription liquid formulation (Imodium A-D 1 mg/5 mL) should be used; for ages 6 to 12, either loperamide hydrochloride capsules or Imodium A-D liquid may be used. For pediatric patients 2 to 12 years of age, the following schedule for capsules or liquid will usually fulfill initial dosage requirements: Recommended First Day Dosage Schedule Two to five years (13 to 20 kg): 1 mg three times daily (3 mg total daily dosage) Six to eight years (20 to 30 kg): 2 mg twice daily. (4 mg total daily dosage) Eight to twelve years (greater than 30kg): 2 mg three times daily (6 mg total daily dosage) Recommended Subsequent Daily Dosage Following the first treatment day, it is recommended that subsequent loperamide hydrochloride capsules doses (1 mg/10 kg body weight) be administered only after a loose stool. The total daily dosage should not exceed recommended dosages for the first day. Chronic Diarrhea Adults The recommended initial dose is 4 mg (two capsules) followed by 2 mg (one capsule) after each unformed stool until diarrhea is controlled, after which the dosage of loperamide hydrochloride capsules should be reduced to meet individual requirements. When the optimal daily dosage has been established, this amount may then be administered as a single dose or in divided doses. The average daily maintenance dosage in clinical trials was 4 to 8 mg (two to four capsules per day). The maximum daily dosage is 16 mg (eight capsules per day). If clinical improvement is not observed after treatment with 16 mg per day for at least 10 days, symptoms are unlikely to be controlled by further administration. Loperamide hydrochloride capsules administration may be continued if diarrhea cannot be adequately controlled with diet or specific treatment. Elderly No formal pharmacokinetic studies were conducted in elderly subjects. However, there were no major differences reported in the drug disposition in elderly patients with diarrhea relative to young patients. No dose adjustment is required for the elderly. In general, elderly patients may be more susceptible to drug-associated effects of the QT interval. Avoid loperamide hydrochloride capsules in elderly patients taking drugs that can result in prolongation of the QT interval (for example, Class IA or III antiarrhythmics) or in patients with risk factors for Torsades de Pointes (see WARNINGS ). Renal Impairment No pharmacokinetic data are available in patients with renal impairment. Since the metabolites and the unchanged drug are mainly excreted in the feces, no dosage adjustment is required for patients with renal impairment (see PRECAUTIONS ). Hepatic Impairment The pharmacokinetics of loperamide have not been studied in patients with hepatic impairment. Use loperamide hydrochloride capsules with caution in such patients because the systemic exposure may be increased due to reduced metabolism (see PRECAUTIONS ).

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.

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 Diarrhea Loperamide Hydrochloride Placebo No. of treated patients 285 277 Gastrointestinal AE% Constipation 5.3% 0.0% Central and peripheral nervous system AE% Dizziness 1.4% 0.7% 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: nausea, vomiting, headache, meteorism, abdominal pain, abdominal cramp and colic. 3) Adverse events from seventy-six controlled and uncontrolled studies in patients with acute or chronic diarrhea The adverse events with an incidence of 1.0% or greater in patients from all studies are given in the table below. Acute Diarrhea Chronic Diarrhea All Studies a No. of treated patients 1913 1371 3740 Gastrointestinal AE% 0.7% 3.2% 1.8% Nausea Constipation 1.6% 1.9% 1.7% Abdominal cramps 0.5% 3.0% 1.4% a. All patients in all studies, including those in which it was not specified if the adverse events occurred in patients with acute or chronic diarrhea. Postmarketing Experience The following adverse events have been reported: Cardiac disorders QT/QTc interval prolongation, Torsades de Pointes, other ventricular arrhythmias, cardiac arrest, syncope, and death (see WARNINGS , OVERDOSAGE ). Skin and subcutaneous tissue disorders Rash, pruritus, urticaria, and angioedema and extremely rare cases bullous eruption including erythema multiforme, Stevens-Johnson syndrome and Toxic Epidermal Necrolysis have been reported with use of loperamide hydrochloride. Immune system disorders Isolated occurrences of allergic reactions and in some cases severe hypersensitivity reactions including anaphylactic shock and anaphylactoid reactions have been reported with the use of loperamide hydrochloride. Gastrointestinal disorders Dry mouth, abdominal pain, distention or discomfort, nausea, vomiting, flatulence, dyspepsia, constipation, paralytic ileus, megacolon; including toxic megacolon (see CONTRAINDICATIONS , WARNINGS ). Renal and urinary disorders Urinary retention Nervous system disorders Drowsiness, dizziness General disorders and administrative site conditions Tiredness A number of the adverse events reported during the clinical investigations and post-marketing experience with loperamide are frequent symptoms of the underlying diarrheal syndrome (abdominal pain/discomfort, nausea, vomiting, dry mouth, tiredness, drowsiness, dizziness, constipation, and flatulence). These symptoms are often difficult to distinguish from undesirable drug effects.

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.