Loperamide/simethicone Loperamide/simethicone Loperamide/simethicone is combination medication marketed under the trade name Imodium Multi-Symptom Relief (formerly Imodium A-D Advanced) used to treat diarrhea and gas simultaneously. It is manufactured by the McNeil Consumer Healthcare Division of McNeil PPC, Inc. Loperamide is a μ-opioid receptor agonist that works in the intestines. Although it is an opioid, it has no effects on the central nervous system. It reduces diarrhea by slowing the transit time of contents through the intestinal tract thereby allowing more water to be reabsorbed from the intestinal lumen. Simethicone reduces gas by allowing smaller gas bubbles to coalesce into larger bubbles
Loperamide on the μ-opioid receptors in the myenteric plexus of the large intestine. Loperamide works like morphine, decreasing the activity of the myenteric plexus, which decreases the tone of the longitudinal and circular smooth muscles of the intestinal wall. This increases the time material stays in the intestine, allowing more water to be absorbed from the fecal matter. Loperamide also decreases colonic mass movements and suppresses the gastrocolic reflex. Loperamide's circulation in the bloodstream is limited in two ways. Efflux by P-glycoprotein in the intestinal wall reduces passage of loperamide, and the fraction of drug crossing is then further reduced through