Colesevelam is a bile acid sequestrant preventing bile acid reabsorption. As the bile acid pool becomes depleted, hepatic conversion of cholesterol into bile acids is promoted, resulting in decreased serum low-density lipoprotein (LDL) cholesterol levels.
A study1 evaluated the efficacy of colesevelam in patients with primary hypercholesterolaemia, randomised to receive placebo or colesevelam for 24 weeks. In each colesevelam treatment group, end point LDL cholesterol levels were significantly decreased compared with baseline. Colesevelam lowered mean LDL cholesterol levels by nine to 18 per cent in a dose-dependent manner.
Another study2 evaluated the efficacy of colesevelam alone and in combination with simvastatin. The mean LDL cholesterol levels declined by 4 per cent in the placebo group, 26 per cent in the colesevelam (3.8g daily) group and 42 per cent in the colesevelam and simvastatin combination group (P<0.0001).
A third study3 evaluated the efficacy of colesevelam alone and in combination with atorvastatin. LDL cholesterol reductions with combination therapy (48 per cent) were statistically superior to colesevelam (12 per cent) or low-dose atorvastatin (38 per cent) alone, but similar to those achieved with atorvastatin 80mg daily (53 per cent).
1. Insull W, Toth P, Mullican W et al. Effectiveness of colesevelam hydrochloride in decreasing LDL cholesterol in patients with primary hypercholesterolemia: a 24-week randomised controlled trial. Mayo Clin Proc 2001: 76; 971–82.
2. Knapp H, Schrott H, Ma P et al. Efficacy and safety of combination simvastatin and colesevelam in patients with primary hypercholesterolemia. Am J Med 2001: 110; 352–60.
3. Hunninghake D, Insull W, Toth P et al. Coadministration of colesevelam hydrochloride with atorvastatin lowers LDL cholesterol additively. Atherosclerosis 2001: 158; 407–16.
Further information: Genzyme 01865 405200