By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New York.

Niacin (nicotinic acid) was the first medication shown to improve the pattern of lipid changes in the blood, which contribute to the development of atherosclerosis. However, in spite of its proven effectiveness, it has not been widely used because of concerns about its side effects, which are of two types - symptomatic (mainly flushing) and asymptomatic (changes that show up on blood tests). To avoid these problems, several long-acting slow-release preparations have been developed, with varying success.

One that does appear to be promising is Niaspan, which is formulated to be taken at night, the time when our bodies make most of the cholesterol that is in our blood. A trial investigated the effects of Niaspan given in doses starting at 375 milligrams every night and gradually increasing to 3,000 milligrams. It was given to 87 patients who had high blood lipids (cholesterol and triglycerides) and compared with 44 patients who were given inert placebo pills. The duration of the trial was 25 weeks, with the dose being increased every four weeks.

The main finding was that the Niaspan resulted in a steady improvement in the blood lipid profile that became progressively better with the higher doses, although the maximum benefit was achieved with the 2,500-milligram dose. At this dose, the following changes were seen:

• LDL cholesterol decreased 22%
• HDL cholesterol increased 30%
• Triglycerides decreased 39%

All of these are beneficial effects. Eight of the 84 patients discontinued the study because of flushing. The interesting thing here was that two-thirds (68%) of the patients reported some flushing with the 500-milligram dose but only 22% with the 3,000-milligram dose. The most likely explanation for this is that flushing wears off after people have been taking the pills for several weeks.

The asymptomatic side effects were generally slight. Although there were some increases in the liver enzymes, these did not reach more than three times the upper limit of the normal values for these tests, which is interpreted as meaning that there was no liver damage. Uric acid levels increased from 5.3 to 7.0 mg/dl. There was, however, a decrease of the blood platelet count of about 15%, which could be of concern in people who have low platelet counts to begin with.

Doctor's comments

This study suggests that when taken as Niaspan, niacin can be a very effective and reasonably well tolerated preparation for lowering cholesterol and triglyceride levels, as well as raising HDL cholesterol. People should be aware that some flushing is to be expected in the early days of taking Niaspan, but that this will wear off with time. As with the statin drugs, the most widely used drugs for lowering cholesterol, blood tests should be taken at regular intervals when taking Niaspan. It is reassuring that the changes in liver enzymes were not a problem.

Where it was published