Aspirin (acetylsalicylic acid) prolongs the length of time that niacin is in
the body.
Niacin affects a class of cholesterol-lowering medications called bile-acid
sequestrants (such as colestipol and cholestyramine); therefore, niacin and
these medications should be taken at different times of the day. When niacin is
taken at the same time as certain cholesterol-lowering medications, the
likelihood for adverse effects, such as muscle inflammation or liver toxicity,
is increased.
When niacin is taken with certain blood pressure medications (such as
prazosin, doxazosin, and guanabenz), the likelihood for side effects from these
medications is increased.
