Imodium - General Information

One of the long-acting synthetic antidiarrheals; it is not significantly absorbed from the gut, and has no effect on the adrenergic system or central nervous system, but may antagonize histamine and interfere with acetylcholine release locally. [PubChem]


Pharmacology of Imodium

Imodium is a synthetic anti-diarrheal indicated for the control and symptomatic relief of acute nonspecific diarrhea and of chronic diarrhea associated with inflammatory bowel disease. Imodium is also indicated for reducing the volume of discharge from ileostomies. In man, Imodium prolongs the transit time of the intestinal contents. It reduces the daily fecal volume, increases the viscosity and bulk density, and diminishes the loss of fluid and electrolytes. Tolerance to the antidiarrheal effect has not been observed. Imodium is an opioid receptor agonist and acts on the mu opioid receptors in the myenteric plexus large intestines; it does not affect the central nervous system like other opioids. It works specifically by decreasing the activity of the myenteric plexus which decreases the motility of the circular and longitudinal smooth muscles of the intestinal wall. This increases the amount of time substances stay in the intestine, allowing for more water to be absorbed out of the fecal matter. Imodium also decreases colonic mass movements and suppresses the gastrocolic reflex.


Imodium for patients

Patients should be advised to check with their physician if their diarrhea does not improve after a couple of days or if they note blood in their stools or develop a fever.


Imodium Interactions

There was no evidence in clinical trials of drug interactions with concurrent medications.


Imodium Contraindications

Loperamide hydrochloride is contraindicated in patients with known hypersensitivity to the drug and in those in whom constipation must be avoided.


Additional information about Imodium

Imodium Indication: For the control and symptomatic relief of acute nonspecific diarrhea and of chronic diarrhea associated with inflammatory bowel disease or gastroenteritis. Also used for reducing the volume of discharge from ileostomies.
Mechanism Of Action: In vitro and animal studies show that Imodium acts by slowing intestinal motility and by affecting water and electrolyte movement through the bowel. Imodium inhibits peristaltic activity by a direct effect on the circular and longitudinal muscles of the intestinal wall. It is a non-selective calcium channel blocker and binds to opioid mu-receptors. Evidence also suggests that at higher concentrations it binds to NMDA receptors and to calmodulin.
Drug Interactions: Not Available
Food Interactions: Take without regard to meals. Increase liquid intake.
Generic Name: Loperamide
Synonyms: Not Available
Drug Category: Antidiarrheals
Drug Type: Small Molecule; Approved

Other Brand Names containing Loperamide: Apo-Loperamide; Diarr-Eze; Imodium; Imodium A-D; Imodium A-D Caplets; Ioperamide; Kaopectate II; Loperacap; Loperamida [INN-Spanish]; Loperamide HCL; Loperamidum [INN-Latin]; Maalox Anti-Diarrheal; Nu-Loperamide; PMS-Loperamide; Pepto Diarrhea Control; Rho-Loperamide;
Absorption: Not significantly absorbed from the gut
Toxicity (Overdose): Oral, mouse: LD50 = 105 mg/kg. Symptoms of overdose include constipation, drowsiness, lethargy, and nausea.
Protein Binding: 97%
Biotransformation: Hepatic
Half Life: 9.1 to 14.4 hours (average 10.8 hours)
Dosage Forms of Imodium: Tablet Oral
Solution Oral
Chemical IUPAC Name: 4-[4-(4-chlorophenyl)-4-hydroxypiperidin-1-yl]-N,N-dimethyl-2,2-di(phenyl)butanamide
Chemical Formula: C29H33ClN2O2
Loperamide on Wikipedia:
Organisms Affected: Humans and other mammals