calcium carbonate + loperamide

**Calcium carbonate + loperamide** is a combination of two active pharmaceutical ingredients: calcium carbonate, an antacid and mineral supplement, and loperamide, a synthetic antidiarrheal agent. Calcium carbonate neutralizes gastric acid, providing relief from heartburn, acid indigestion, and upset stomach by increasing gastric pH through a simple acid-base reaction. Loperamide is a peripheral mu-opioid receptor agonist that acts on the intestinal wall to slow peristalsis, reduce gastrointestinal secretion, and increase the absorption of fluids and electrolytes, resulting in decreased stool frequency, consistency, and urgency. Their combination may theoretically be used for symptomatic relief in conditions presenting with both diarrhea and gastric hyperacidity, although no standard fixed-dose combination product of these two drugs appears widely available or approved.