Questran is a medication classified as a bile acid seQuestrant used to treat certain lipid disorders. Its active ingredient, cholestyramine, binds to bile acids in the intestinal lumen. By forming insoluble complexes, it reduces the reabsorption of bile acids. The bound bile acids are excreted in feces, prompting the liver to convert cholesterol into additional bile acid production. Increased cholesterol catabolism leads to a subsequent decrease in circulating low-density lipoprotein cholesterol levels. The lowered ldl cholesterol provides cardiovascular benefit in patients with hypercholesterolemia. Questran also serves as an adjunct therapy to reduce the absorption of dietary fat and to improve glycemic control in selected individuals with type 2 diabetes. Because the drug acts only in the gastrointestinal tract and is not systemically absorbed, its pharmacological effects are confined to the gut lumen.

Questran is a cholesterol-lowering resin taken orally to reduce ldl levels. It binds bile acids in the intestinal lumen to prevent their reabsorption. This binding increases bile acid loss in feces and prompts the liver to make more cholesterol for bile production. The extra cholesterol conversion raises expression of ldl receptors on cell surfaces. More ldl receptors improve clearance of ldl particles from the bloodstream. As a result plasma cholesterol concentrations fall without directly altering cholesterol synthesis. The drug therefore provides a lipid-lowering effect through intestinal sequestration of bile acids.

Constipation is one of the most frequently reported side effects of Questran. Some patients may experience mild abdominal discomfort or bloating. Headache can occur occasionally during treatment. Dizziness or light-headedness may be reported. Nausea or vomiting are less common but have been observed. Flatulence may increase in certain individuals. Rarely patients notice a change in taste sensation. These effects are generally mild and often improve with continued use.

Common side effects of Questran include constipation stomach discomfort and mild nausea. Some individuals may experience bloating or gas during treatment. Headache and dizziness are also reported in a minority of patients. Fatigue and muscle aches can occur but are generally mild. Changes in blood fat levels may be observed but typically do not cause symptoms. Serious adverse events are rare and not typically linked to standard dosing.