Niacin

Commonly reported side effects of niacin include: pruritus, nausea, and flushing. Other side effects include: skin rash, and vomiting. See below for a comprehensive list of adverse effects.

Applies to niacin: oral capsule, oral capsule extended release, oral tablet, oral tablet extended release

Along with its needed effects, niacin may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking niacin:

Less common

• Darkening of urine
• light gray-colored stools
• loss of appetite
• severe stomach pain
• yellow eyes or skin

Some side effects of niacin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• Abdominal or stomach pain
• cough
• diarrhea
• feeling of warmth
• flushing or redness of the skin, especially on the face and neck
• headache
• nausea or vomiting
• rash or itching
• runny nose
• sneezing
• stuffy nose

Incidence not known

• Dizziness or faintness
• dryness of the skin
• fever
• frequent urination
• joint pain
• muscle aching or cramping
• side, lower back, or stomach pain
• swelling of the feet or lower legs
• unusual thirst
• unusual tiredness or weakness
• unusually fast, slow, or irregular heartbeat

Applies to niacin: compounding powder, oral capsule, oral capsule extended release, oral liquid, oral tablet, oral tablet extended release

Very common (10% or more): Flushing (i.e., warmth, redness, itching, and/or tingling) (up to 88%)

Frequency not reported: Tachycardia, palpitations, atrial fibrillation, other cardiac arrhythmias, syncope, hypotension, postural hypotension

Common (1% to 10%): Rash, pruritus

Frequency not reported: Sweating, skin burning sensation, maculopapular rash, dry skin

Postmarketing reports: Skin discoloration

Very common (10% or more): Diarrhea (up to 14%), nausea (up to 11%)

Common (1% to 10%): Vomiting

Frequency not reported: Peptic ulcers, eructation, flatulence

Postmarketing reports: Slight reductions in platelet counts, prothrombin time prolonged

Postmarketing reports: Hypersensitivity reactions (e.g., anaphylaxis, angioedema, urticaria, flushing, dyspnea, tongue edema, larynx edema, face edema, peripheral edema, laryngismus, vesiculobullous rash)

Postmarketing reports: Hepatitis, jaundice

Frequency not reported: Decreased glucose tolerance, gout

Frequency not reported: Myalgia, myopathy

Frequency not reported: Dizziness, syncope

Postmarketing reports: Migraine, asthenia, paresthesia

Postmarketing reports: Blurred vision, macular edema

Postmarketing reports: Insomnia, nervousness

Frequency not reported: Chills, edema

Common (1% to 10%): Cough increased

Frequency not reported: Dyspnea