Colesevelam + niacin

Absorption of certain drugs, including those with neutral or cationic charge as well as anions, may be impaired by the resins. These include digitalis glycosides, thiazides, warfarin, tetracycline, thyroxine, iron salts, pravastatin, fluvastatin, folic acid, phenylbutazone, aspirin, and ascorbic acid. Any additional medication (except niacin) should be given 1 hour before or at least 2 hours after the resin to ensure adequate absorption. Colesevelam does not bind digoxin, warfarin, or reductase inhibitors. 

Any additional medication (except niacin) should be given 1 hour before or at least 2 hours after the resin to ensure adequate absorption. Colesevelam does not bind digoxin, warfarin, or reductase inhibitors. 

The reduction in IDL-C by resins is dose-dependent. Doses of 8-12 g of cholestyramine or 10-15 g of colestipol are associated with 12-18% reductions in LDL-C. Maximal doses (24 g of cholestyramine, 30 g of colestipol) may reduce LDDC by as much as 25%, but will cause GI side effects that are poorly tolerated by most patients. One to two weeks is sufficient to attain maximal LDDC reduction by a given resin dose. In patients with normal triglyceride levels, triglycerides may increase transiently and then return to baseline. HDL-C levels increase 4-5%. Statins plus resins or niacin plus resins can reduce LDL-C by as much as 40-60%. Colesevelam, in doses of 3-3.75 g, reduces LDL-C levels by 9-19%. 

Bile acid sequestrants are indicated for the treatment of hypercholesterolemia in patients who do not adequately respond to dietary modifications. They may be used either alone or in combination with HMGRIs or niacin. These combinations often can achieve a 50% reduction in plasma LDL levels. Cholestyramine, but neither colestipol nor colesevelam, also is approved for the relief of pruritus associated with partial biliary obstruction. Bile acid sequestrants should not be used to treat hypertriglyceridemias or mixed hyperlipoproteinemias in which hypertriglyceridemia is the primary concern. These compounds also are contraindicated in patients with cholelithiasis or complete biliary obstruction because of the impaired secretion of bile acids caused by these conditions. Finally, cholestyramine and colestipol are contraindicated in patients with primary biliary cirrhosis, because this can further raise serum cholesterol (7,15,21). 

Davidson MH, Rooney M, Pohock E, Drucker J, Choy Y. Effect of colesevelam and niacin on low-density hpoprotein cholesterol and gjycemic control in subjects with dyshpidemia and impaired fasting glucose. J Chn lipid 2013 7 423-32. 

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