Safety of niacin and simvastatin combination therapy.

Niacin is the most potent lipid-altering agent for raising high-density lipoprotein (HDL) cholesterol levels. Niacin also lowers triglyceride (TG) levels, lowers low-density lipoprotein (LDL) cholesterol levels, and improves lipoprotein particle size and subclass distribution. Niacin's major adverse experience (AE) is flushing. Niacin may also increase glucose levels, liver enzymes, and uric acid levels and cause other AEs that may have clinical relevance in selected patients. Simvastatin is representative of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin) class of lipid-altering drugs, which are the most effective agents for lowering LDL cholesterol levels and also have modest benefits in raising HDL cholesterol and lowering TG levels. The most common AEs with statins are muscle AEs and modest liver enzyme elevations. Because niacin and statins have complementary lipid effects and because individually, niacin and statins have been shown in outcomes studies to reduce atherosclerotic coronary artery disease events, the combined use of these 2 agents has significant potential to not only improve the lipid values of patients but improve their lives as well. Equally important is ensuring that the combination of niacin and simvastatin has an acceptable safety profile, with no greater AEs than would otherwise be expected by adding 1 agent to the other.