Loperamide bloody diarrhea. In 1990, all formulations for children of the antidiarrheal loperamide were banned in Pakistan. Loperamide is not recommended in the UK for use during pregnancy or by nursing mothers. In the US, loperamide is classified by the FDA as pregnancy category C. Studies in rat models have shown no teratogenicity, but sufficient studies in humans have not been conducted. One controlled, prospective study of 89 women exposed to loperamide during their first trimester of pregnancy showed no increased risk of malformations. This, however, was only one study with a small sample size. Loperamide can be present in breast
Loperamide milk, and is not recommended for breast-feeding mothers. Loperamide is a substrate of P-glycoprotein; therefore, the concentration of loperamide will increase when given with a P-glycoprotein inhibitor. Common P-glycoprotein inhibitors include quinidine, ritonavir, and ketoconazole, among others. Loperamide is capable of decreasing the absorption of some other drugs. As an example, saquinavir concentrations can decrease by half when given with loperamide. Loperamide is an antidiarrheal agent which decreases intestinal movement. As such, when combined with other antimotility drugs, the risk of constipation is increased. These drugs include other opioids, antihistamines, antipsychotics, and anticholinergics. Loperamide is an opioid-receptor agonist and acts