Niacin Drug Interactions Explained
The following sections explain in detail the potentially negative interactions that can occur when
niacin is combined with any of the drugs listed above.
Alcohol
Drinking alcohol around the same time you take a dose of niacin may increase the risk of flushing. You may want to avoid alcohol near any niacin doses, especially if you experience bothersome flushing.
Alpha Blockers
Taking niacin with an alpha blocker may cause an unsafe drop in
blood pressure. Check with your healthcare provider before taking niacin with an alpha blocker.
Aspirin
Aspirin may increase the level of niacin in your blood (by decreasing its breakdown in the liver). However, this is probably not significant, especially at aspirin doses recommended for preventing the
niacin flush (such as 325 mg or less). Only much higher aspirin dosages would be expected to produce any significant changes.
Beta Blockers
Taking niacin with a
beta blocker may cause an unsafe drop in blood pressure. Check with your healthcare provider before taking niacin with a beta blocker.
Bile Acid Sequestrants
Bile acid sequestrants can bind to niacin in the digestive tract, preventing it from being absorbed into the bloodstream. This interaction can make niacin much less effective. In order to avoid this interaction, it is important to separate doses of niacin and a bile acid sequestrant by at least four to six hours. This might not be possible with immediate-release niacin (which is taken several times a day). In such cases, it may be best to switch to extended-release niacin (
Niaspan®), which is taken just once a day at bedtime.
Calcium Channel Blockers
Taking niacin with a
calcium channel blocker may cause an unsafe drop in blood pressure. Check with your healthcare provider before taking niacin with a
calcium channel blocker.