Abstracts

Niacin (nicotinic acid) in large pharmacological doses (500 mg or more per day) favorably modifies the lipid profile. Niacin lowers total cholesterol, lowers low-density lipoprotein, raises high-density lipoprotein, lowers triglycerides, and lowers lipoprotein(a). It also modifies other known cardiovascular risk factors such as fibrinogen and C-reactive protein. Unfortunately the hypolipidemic effects of niacin increases plasma homocysteine levels, which would potentially increase the risk of cardiovascular events. A case report is presented to demonstrate niacin's hypolipidemic effects and its ability to markedly raise plasma homocysteine levels. Immediate-release preparations of niacin are safer than slow- or sustained-release preparations. Immediate-release preparations cause a transient cutaneous flush that is more pronounced than slow- or sustained-release preparations. Since niacin preparations can cause hepatic toxicity regular monitoring of transaminases are important. The first symptoms of toxicity typically include nausea and possibly vomiting necessitating discontinuation of the therapy. The rise in plasma homocysteine levels does not appear to be correctable by oral supplementation of B-vitamins. Regular parenteral administration of vitamin B12 seems to be required in order to lower plasma homocysteine when taking large pharmacological doses of niacin. More controlled trials are necessary in terms of primary end points if niacin is ever going to gain wider acceptance among both mainstream and complementary health practitioners. Investigation into the best and most cost-effective method for lowering plasma homocysteine while on niacin therapy requires further study.