Nicotinic acid, acipimox or niacin appear to exert their effects by inhibiting lipoprotein synthesis and decreasing the production of VLDL particles by the liver. They inhibit the peripheral mobilization of free fatty acids, thus reducing hepatic synthesis of triglycerides and the secretion of VLDL. It also reduces apoB. The net result is a reduction in VLDL particles secreted by the liver and thus less substrate to make LDL particles. It increases the production of apoA-I and thereby HDL through mechanisms that are not clear.
Niacin is the best
agent available for raising HDL-C and, in patients with mixed hyperlipidemia, shifts cholesterol from small LDL particles to larger ones.
Its primary limitation is its side effects. Niacin can cause flushing, itching, and headache, which limit the number of people who are willing or able to tolerate therapy on a long-term basis. Because of the risk of hepatotoxicity, daily doses of these products should not exceed 2 g, and close monitoring of liver function should accompany use of these products. Other side effects include activation of peptic ulcer, hyperglycemia, and gout, and worsening of diabetes. Niacin reduces insulin sensitivity and often worsens hyperglycemia in persons with type 2 diabetes. A new generation of slow release tablets decreases the side effects.
A patient with familial chylomicronemia syndrome (FCS) has the most benefit of treatment with
Extra info: FCS is characterized by very high triglyceride levels and mildly increased total cholesterol. Therefore, reduction of triglycerides is of high importance. Gemfibrozil is drug of choice in this case, because of its triglyceride-lowering and cholesterol-lowering properties. Acipimox has the same properties, but is more expensive. Fish oils also lower triglycerides, but are less effective and can be used as additional therapy.
Acipimox is prescribed for patients with hypertriglyceridemia when
Extra info: In case of hypertriglyceridemia, nicotinic acid or a fibrate is the drug of choice, not a statin. Acipimox is contraindicated for patients with gout. Acipimox can worsen diabetes, resulting in hyperglycemia.