Effects of colesevelam HC1 on sterol and bile acid excretion in patients with type IIa hypercholesterolemia.

Colesevelam HC1 is a potent bile acid-binding polymer. This study's aim was to determine effects of colesevelam HCl on sterol and bile acid excretion in patients with type IIa hypercholesterolemia. Twenty-four patients (low-density lipoprotein cholesterol, 130 to 220 mg/dL) enrolled in an open-label, parallel-design study, entered an American Heart Association/National Cholesterol Education Program diet for 6 weeks and were randomized to colesevelam HCl, 2.3 or 3.8 g/day for 4 weeks. In an apparent dose-related manner, respective mean serum concentrations HCl of low-density lipoprotein cholesterol decreased by 10% (P < 0.01) and 13% (P = 0.05), mean total cholesterol levels decreased by 4.9% (P = 0.05) and 6.1% (P = 0.09), and total fecal bile acid excretion showed median changes of +324% (P < 0.05) and +316% (P < 0.05). Colesevelam HCl did not affect fecal neutral sterol or fecal fatty acid excretion; however, 24-hr urinary mevalonic acid levels significantly increased in both treatment groups (P < 0.05). The cholesterol-lowering action of colesevelam HCl appears to be mediated through increased bile acid excretion.