What restricts the clinical use of nicotinic acid?

Nicotinic acid is the oldest hypolipidemic agent in use, since 1955. It possesses broad-spectrum lipidmodifying properties including reduction of total cholesterol, low density lipoprotein (LDL) cholesterol and triglycerides. In addition, nicotinic acid is the most potent available hypolipidemic agent for increasing plasma high density lipoprotein (HDL) cholesterol and decreasing lipoprotein (a) levels. Clinical trials have demonstrated that nicotinic acid can decrease cardiovascular morbidity and mortality. However, nicotinic acid is underused in the clinical setting due to its high rate of side effects, including flushing, gastrointestinal disorders, rash, hyperglycemia and hyperuricemia. The nicotinic acid-associated side effects and their management are the focus of this review.