Overview
DESCRIPTION Each five-sided dye free MOTOFEN ® tablet contains: 1 mg of difenoxin (equivalent to 1.09 mg of difenoxin hydrochloride) and 0.025 mg of atropine sulfate (equivalent to 0.01 mg of atropine). Difenoxin hydrochloride, 1-(3-cyano-3,3-diphenylpropyl)-4-phenyl-4-piperidinecarboxylic acid monohydrochloride, is an orally administered antidiarrheal agent which is chemically related to the...
Mechanism of Action
CLINICAL PHARMACOLOGY Animal studies have shown that difenoxin hydrochloride manifests its antidiarrheal effect by slowing intestinal motility. The mechanism of action is by a local effect on the gastrointestinal wall. Difenoxin is the principal active metabolite of diphenoxylate. Following oral administration of MOTOFEN ® , difenoxin is rapidly and extensively absorbed. Mean peak plasma levels of approximately 160 ng/mL occurred within 40 to 60 minutes in most patients following an oral dose of 2 mg. Plasma levels decline to less than 10% of their peak values within 24 hours and to less than 1% of their peak values within 72 hours. This decline parallels the appearance of difenoxin and its metabolites in the urine. Difenoxin is metabolized to an inactive hydroxylated metabolite.
Indications
- INDICATIONS AND USAGE MOTOFEN ® is indicated as adjunctive therapy in the management of acute nonspecific diarrhea and acute exacerbations of chronic functional diarrhea.
Common Doses
- Refer to label
Dosage
DOSAGE AND ADMINISTRATION The recommended starting dose of MOTOFEN ® tablets in adults is 2 tablets then 1 tablet after each loose stool or 1 tablet every 3 to 4 hours as needed, but the total dosage during any 24-hour treatment period should not exceed 8 tablets. In the treatment of diarrhea, if clinical improvement is not observed in 48 hours, continued administration of this type of medication is not recommended. For acute diarrheas and acute exacerbations of functional diarrhea, treatment beyond 48 hours is usually not necessary.
Contraindications
- CONTRAINDICATIONS MOTOFEN ® is contraindicated in patients with diarrhea associated with organisms that penetrate the intestinal mucosa (toxigenic E. coli, Salmonella species, Shigella ) and pseudomembranous colitis associated with broad spectrum antibiotics. Antiperistaltic agents should not be used in the conditions because they may prolong and/or worsen diarrhea. MOTOFEN ® is contraindicated in children under 2 years of age because of the decreased margin of safety of drugs in this class in younger age groups.
Side Effects
- ADVERSE REACTIONS In view of the small amount of atropine present (0.025 mg/tablet), such effects such as dryness of the skin and mucous membranes, flushing, hyperthermia, tachycardia and urinary retention are very unlikely to occur, except perhaps in children. Many of the adverse effects reported during clinical investigation of MOTOFEN ® are difficult to distinguish from symptoms associated with the diarrheal syndrome.
Interactions
- Drug Interactions Since the chemical structure of difenoxin hydrochloride is similar to meperidine hydrochloride, the concurrent use of MOTOFEN ® with monoamine oxidase inhibitors may, in theory, precipitate a hypertensive crisis. MOTOFEN ® may potentiate the action of barbiturates, tranquilizers, narcotics, and alcohol. When these medications are used concomitantly with MOTOFEN ® , the patient should be closely monitored.