If you are currently being treated with any of the following medications, you
should not use niacin without first talking to your healthcare provider.
Niacin should not be taken at the
same time as the antibiotic tetracycline because it interferes with the
absorption and effectiveness of this medication. Niacin either alone or in
combination with other B vitamins should be taken at different times from
tetracycline. (All vitamin B complex supplements act in this way and should
therefore be taken at different times from tetracycline.)
Taking aspirin before taking niacin may reduce
flushing associated with this vitamin. This should only be done under the advice
of a healthcare practitioner.
Blood Pressure Medications, Alpha-blockers
When niacin is
taken with certain blood pressure medications known as alpha-blockers (such as
prazosin, doxazosin, and guanabenz), the likelihood of side effects from these
medications is increased.
Niacin binds bile-acid
sequestrants (cholesterol-lowering medications such as colestipol, colesevelam,
and cholestyramine) and may decrease their effectiveness. For this reason,
niacin and these medications should be taken at different times of the day.
As described earlier, recent scientific evidence suggests that taking niacin
with simvastatin (a drug that belongs to a class of cholesterol-lowering
medications known as HMG-CoA reductase inhibitors or statins including
atorvastatin and lovastatin as well), appears to slow down the progression of
heart disease. However, the combination may also increases the likelihood for
serious side effects, such as muscle inflammation or liver damage.
People taking insulin, metformin,
glyburide, glipizide, or other medications used to treat high blood sugar levels
should monitor their blood sugar levels closely when taking niacin supplements.
INH, a medication used to treat tuberculosis,
may deplete levels of niacin and cause a deficiency.
The use of nicotine patches with niacin may
worsen or increase the risk of flushing reactions associated with this vitamin
when used medicinally.