Can a person be allergic to niacin?

Answer 1

Toxicity People taking pharmacological doses of niacin (1.5 - 6 g per day) often experience side-effects that can include dermatological complaints such as facial flushing and itching, dry skin, skin rashes including acanthosis nigricans. Gastrointestinal complaints, such as dyspepsia (indigestion) and liver toxicity (fulminant hepatic failure) have also been reported. Also reported include hyperglycemia, cardiac arrhythmias, birth defects, and orthostasis. * Facial flushing is the most commonly reported side effect.It lasts for about 15 to 30 minutes, and is sometimes accompanied by a prickly or itching sensation, particularly in areas covered by clothing. This effect is mediated by prostaglandin and can be blocked by taking 300 mg of aspirin half an hour before taking niacin, or by taking one tablet of ibuprofen per day. Taking the niacin with meals also helps reduce this side effect. After 1 to 2 weeks of a stable dose, most patients no longer flush. Slow- or "sustained"-release forms of niacin have been developed to lessen these side-effects.One study showed the incidence of flushing was significantly lower with a sustained release formulation though doses above 2 g per day have been associated with liver damage, particularly with slow-release formulations. * High-dose niacin may also elevate blood sugar, thereby worsening Diabetes mellitus. * Hyperuricemia is another side-effect of taking high-dose niacin, and may exacerbate gout. * Niacin at doses used in lowering cholesterol has been associated with birth defects in laboratory animals, with possible consequences for infant development in pregnant women. Niacin at extremely high doses can have life-threatening acute toxic reactions.Extremely high doses of niacin can also cause niacin maculopathy, a thickening of the macula and retina which leads to blurred vision and blindness. This maculopathy is reversible after stopping niacin intake.