– Niacin could increase your uric
acid levels, increasing your chances of experiencing a gouty attack.
Gallbladder disease – Taking niacin with
gallbladder disease could increase the formation of gallstones, or worsen
your gallbladder disease.
– Diabetics taking niacin could note an increase in fasting blood sugar
levels. Although this is usually modest (about 5%), it may be noticeable in
cases of where blood sugar levels are well controlled.
Liver disease – Taking niacin could increase
liver enzyme levels, which could be even higher in individuals already
diagnosed with liver disease.
Kidney disease - Having poor kidney function may
cause niacin to accumulate in your blood, possibly toxic effects.
Pregnancy – There have not been enough studies
to adequately assess the safety of niacin on your baby. Therefore, you
should consult your healthcare provider if you are pregnant, or planning to
Breast feeding – Studies have shown that
niacin is excreted in breast milk, however, it is not fully known if doses
given to lower cholesterol could also harm the baby. Therefore, you should
consult your healthcare provider before taking niacin.
disease – Taking niacin could worsen certain cardiovascular
conditions, such as unstable angina.
- Taking multiple medications – just because it’s over-the-counter, it doesn’t mean that it’s completely safe. Certain medications could also interact with niacin, either decreasing the effectiveness of certain medications, or increasing toxic effects of other drugs.
If you have any of the above conditions, you should talk to your healthcare provider before starting niacin on your own. Having one or more of these conditions won’t necessarily prevent you from taking niacin, however, your healthcare provider may want to assess your condition before initiating it, and monitor for any complications after you've started taking niacin.
Micromedex Healthcare Series [Internet database].Greenwood Village, CO: Thomson Reuters (Healthcare) Inc. Updated periodically.
Dipiro JT, Talbert RL. Pharmacotherapy: A Pathophysiological Approach, 7th ed 2008.