Niaspan Side Effects Center

Last updated on RxList: 7/19/2022
Niaspan Side Effects Center

What Is Niaspan?

Niaspan (niacin) is a B-complex vitamin used along with dietary changes (restriction of cholesterol and fat intake) to reduce the amount of cholesterol and certain fatty substances in the blood. Niaspan is also used to prevent and treat pellagra, also known as niacin deficiency, a disease caused by inadequate diet and other medical problems. Niaspan is available in generic form.

What Are Side Effects of Niaspan?

Common side effects of Niaspan include:

  • headache,
  • dizziness,
  • flushing (warmth, redness, or tingly feeling under your skin),
  • itching,
  • dry skin,
  • sweating,
  • chills,
  • muscle pain,
  • leg cramps,
  • sleep problems (insomnia),
  • blurred vision,
  • nausea,
  • vomiting,
  • diarrhea,
  • belching,
  • gas.

Niaspan may cause serious side effects including:

  • lightheadedness,
  • irregular heartbeats,
  • severe warmth or redness under the skin,
  • vision problems, and
  • yellowing of the skin or eyes (jaundice)

Get medical help right away, if you have any of the symptoms listed above.

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheartedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Niaspan

Niaspan is available as a tablet or an extended-release tablet to be taken orally. It should be taken at bedtime, after a low-fat snack. Doses should be individualized according to patient response.

  • Therapy with Niaspan must be initiated at 500 mg at night to reduce the incidence and severity of side effects that may occur during early treatment.

What Drugs, Substances, or Supplements Interact with Niaspan?

Niaspan may interact with other cholesterol-lowering drugs, blood thinners, multivitamins or mineral supplements that contain niacin, blood pressure medications, bile acid sequestrants, aspirin, or heart medications such as statins. Tell your doctor all medications and supplements you use.

Niaspan During Pregnancy and Breastfeeding

If patients become pregnant, they should stop taking Niaspan and consult with their doctor. Women who are breastfeeding should not use Niaspan.

Additional Information

Our Niaspan Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Niaspan Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;
  • irregular heartbeats;
  • severe warmth or redness under your skin;
  • vision problems; or
  • jaundice (yellowing of the skin or eyes).

Common side effects may include:

  • flushing (sudden warmth, redness, or tingly feeling);
  • upset stomach, vomiting, diarrhea;
  • abnormal liver function tests;
  • itching, dry skin;
  • cough;
  • skin discoloration; or
  • headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Niaspan Professional Information


Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

Clinical Studies Experience

In the placebo-controlled clinical trials database of 402 patients (age range 21-75 years, 33% women, 89% Caucasians, 7% Blacks, 3% Hispanics, 1% Asians) with a median treatment duration of 16 weeks, 16% of patients on NIASPAN and 4% of patients on placebo discontinued due to adverse reactions. The most common adverse reactions in the group of patients treated with NIASPAN that led to treatment discontinuation and occurred at a rate greater than placebo were flushing (6% vs. 0%), rash (2% vs. 0%), diarrhea (2% vs. 0%), nausea (1% vs. 0%), and vomiting (1% vs. 0%). The most commonly reported adverse reactions (incidence >5% and greater than placebo) in the NIASPAN controlled clinical trial database of 402 patients were flushing, diarrhea, nausea, vomiting, increased cough and pruritus.

In the placebo-controlled clinical trials, flushing episodes (i.e., warmth, redness, itching and/or tingling) were the most common treatment-emergent adverse reactions (reported by as many as 88% of patients) for NIASPAN. Spontaneous reports suggest that flushing may also be accompanied by symptoms of dizziness, tachycardia, palpitations, shortness of breath, sweating, burning sensation/skin burning sensation, chills, and/or edema, which in rare cases may lead to syncope. In pivotal studies, 6% (14/245) of NIASPAN patients discontinued due to flushing. In comparisons of immediate-release (IR) niacin and NIASPAN, although the proportion of patients who flushed was similar, fewer flushing episodes were reported by patients who received NIASPAN. Following 4 weeks of maintenance therapy at daily doses of 1500 mg, the incidence of flushing over the 4-week period averaged 8.6 events per patient for IR niacin versus 1.9 following NIASPAN.

Other adverse reactions occurring in ≥5% of patients treated with NIASPAN and at an incidence greater than placebo are shown in Table 2 below.

Table 2: Treatment-Emergent Adverse Reactions by Dose Level in ≥ 5% of Patients and at an Incidence Greater than Placebo; Regardless of Causality Assessment in Placebo-Controlled Clinical Trials

Placebo-Controlled Studies NIASPAN [email protected]
(n=157) %
500 mg‡
(n=87) %
Recommended Daily Maintenance Doses†
1000 mg
(n=110) %
1500 mg
(n=136) %
2000 mg
(n=95) %
Gastrointestinal Disorders
Cough, Increased632< 28
Skin and Subcutaneous Tissue Disorders
Vascular Disorders
Note: Percentages are calculated from the total number of patients in each column.
† Adverse reactions are reported at the initial dose where they occur.
@ Pooled results from placebo-controlled studies; for NIASPAN, n=245 and median treatment duration=16 weeks. Number of NIASPAN patients (n) are not additive across doses.
‡ The 500 mg/day dose is outside the recommended daily maintenance dosing range [see DOSAGE AND ADMINISTRATION].
& 10 patients discontinued before receiving 500 mg, therefore they were not included.

In general, the incidence of adverse events was higher in women compared to men.

Atherothrombosis Intervention In Metabolic Syndrome With LOW HDL/High Triglycerides: Impact On Global Health Outcomes (AIM-HIGH)

In AIM-HIGH involving 3414 patients (mean age of 64 years, 15% women, 92% Caucasians, 34% with diabetes mellitus) with stable, previously diagnosed cardiovascular disease, all patients received simvastatin, 40 to 80 mg per day, plus ezetimibe 10 mg per day if needed, to maintain an LDL-C level of 40-80 mg/dL, and were randomized to receive NIASPAN 1500-2000 mg/day (n=1718) or matching placebo (IR Niacin, 100-150 mg, n=1696). The incidence of the adverse reactions of “blood glucose increased” (6.4% vs. 4.5%) and “diabetes mellitus” (3.6% vs. 2.2%) was significantly higher in the simvastatin plus NIASPAN group as compared to the simvastatin plus placebo group. There were 5 cases of rhabdomyolysis reported, 4 (0.2%) in the simvastatin plus NIASPAN group and one (<0.1%) in the simvastatin plus placebo group [see WARNINGS AND PRECAUTIONS].

Postmarketing Experience

Because the below reactions are reported voluntarily from a population of uncertain size, it is generally not possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The following additional adverse reactions have been identified during post-approval use of NIASPAN:

Hypersensitivity reactions, including anaphylaxis, angioedema, urticaria, flushing, dyspnea, tongue edema, larynx edema, face edema, peripheral edema, laryngismus, and vesiculobullous rash; maculopapular rash; dry skin; tachycardia; palpitations; atrial fibrillation; other cardiac arrhythmias; syncope; hypotension; postural hypotension; blurred vision; macular edema; peptic ulcers; eructation; flatulence; hepatitis; jaundice; decreased glucose tolerance; gout; myalgia; myopathy; dizziness; insomnia; asthenia; nervousness; paresthesia; dyspnea; sweating; burning sensation/skin burning sensation; skin discoloration, and migraine.

Clinical Laboratory Abnormalities


Elevations in serum transaminases [see WARNINGS AND PRECAUTIONS], LDH, fasting glucose, uric acid, total bilirubin, amylase and creatine kinase, and reduction in phosphorus.


Slight reductions in platelet counts and prolongation in prothrombin time [see WARNINGS AND PRECAUTIONS].

Read the entire FDA prescribing information for Niaspan (Niacin)

© Niaspan Patient Information is supplied by Cerner Multum, Inc. and Niaspan Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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