Loperamide/simethicone in the intestinal tract, making them easier to pass. Simethicone is not absorbed from the gastrointestinal tract so there are no systemic side effects. Anti-diarrheal medications should be avoided if diarrhea is secondary to an infection. Avoid using such products in the presence of fever, black stools, bloody stools, or stools containing mucus. 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
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