Health Guide


What is it?

Niacin is a vitamin used to treat high cholesterol, pellagra (not having enough niacin in the body), Raynaud's disease, and atherosclerosis (clogged arteries).

Other names for niacin include: inositol hexaniacinate, vitamin B3, niacinamide, nicotinamide, and nicotinic acid.

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement).
  • are pregnant or plan to become pregnant while using this medicine.
  • are breastfeeding.
  • have liver disease, a stomach ulcer, or bleeding problems (2,12,27).
  • have any other health problems, such as high blood pressure or heart or blood vessel disease.


Talk with your caregiver about how much niacin you should take. The amount depends on the strength of the medicine and the reason you are taking niacin. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take niacin without talking to your doctor first if you are taking:

  • Alcohol (11)
  • Cholesterol lowering medicine (examples: atorvastatin (Lipitor(R)), colestipol (Colestid(R)), cholestyramine (Questran(R)), pitavastatin (Livalo(R)), simvastatin (Zocor(R)), pravastatin (Pravachol(R))) (6,7,28)
  • Herbs such as chaparral, comfrey, germander, jin bu huan, kava, valerian, skullcap, or pennyroyal (even in a tea form) (20,21,22,25,26)
  • Medicine to lower blood pressure, such as atenolol, dilitiazem, nifedipine, propranolol, verapamil, Cartia(R), Coreg(R), Lotrel(R), Norvasc(R), Plendil(R), Tiazac(R), or Toprol(R) (27)
  • Nicotine (or if you are a smoker) (8)
  • Nitrates, such as nitroglycerin or isosobide (27)
  • Warfarin (Coumadin(R)) (29)


  • Before taking niacin, tell your doctor if you are pregnant or breastfeeding.
  • Do not take niacin if you have liver disease, kidney disease, or a stomach ulcer (9,10,12,25).
  • Before taking niacin, make sure your doctor knows if you have diabetes, angina (chest pain), low blood pressure, gallbladder disease, or gout (24,27).
  • Follow your doctor's instructions carefully if you are switching to this medicine from another form of niacinamide. The dose may be different if you switch from the regular tablet to the extended-release tablet (27).
  • Your doctor will need to check your blood at regular visits while you are using this medicine. Be sure to keep all appointments (27).
  • Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests (27).
  • This medicine may cause a warmth or redness in your face, neck, arms, or upper chest. This is called "flushing," and it usually improves after you have been taking niacin on a regular basis for a few weeks. To help prevent flushing, do not drink alcohol or hot drinks when you take this medicine, and do not take it on an empty stomach. You should also ask your doctor about taking aspirin or an anti-inflammatory medicine (such as ibuprofen) before you use this medicine (27).

Side Effects:

Call your doctor right away if you have any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hand, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash
  • Dark-colored urine or pale stools (12,13,27)
  • Fast, uneven, or pounding heartbeat (27)
  • Nausea, vomiting, loss of appetite, pain in your upper stomach (12,13,27)
  • Yellowing of your skin or the whites of your eyes (12,13,27)

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Blood sugar changes (12)
  • Blood pressure changes (1)
  • Dizziness (1)
  • Skin flushing (redness of skin) and a feeling of warmth (12)
  • Skin rash with or without itching and tingling (12)
  • Headache (27)
  • Lightheadedness or fainting (27)
  • Mild diarrhea, vomiting, or upset stomach (12,27)
  • Muscle pain, tenderness, or weakness (27)
  • Vision changes (27)


1. Product Information: Nicolar(R), niacin. Rhone-Poulenc Rorer Pharmaceuticals, Fort Washington, PA; 1996.

2. Patterson DJ, Dew EW, Gyorkey F et al: Niacin hepatitis. South Med J 1983; 76(2):239-241.

3. Cohen L & Morgan J: Effectiveness of individualized long-term therapy with niacin and probucol in reduction of serum cholesterol. J Fam Pract 1988; 26:145-150.

4. Taketomo CK, Hodding JH & Kraus DM: Pediatric Dosage Handbook, 5th ed. Lexicomp, Hudson, Ohio; 1998:783.

5. Darras BT, Ampola MG, Dietz WH et al: Intermittent dystonia in Hartnup disease. Pediatr Neurol 1989; 5:118-120.

6. Product Information: Lipitor(TM), atorvastatin. Parke-Davis, Morris Plains, NJ; 1996.

7. Product Information: Baycol(TM), cerivastatin sodium. Bayer Corporation, West Haven, CT; 1997.

8. Rockwell KA: Potential interaction between niacin and transdermal nicotine (letter). Ann Pharmacother 1993;27:1283-1284.

9. Patterson DJ, Dew EW, Gyorkey F et al: Niacin hepatitis. South Med J 1983; 76:240-241.

10. Crouse JR III: New developments in the use of niacin for treatment of hyperlipidemia: new considerations in the use of an old drug. Coronary Artery Disease 1996; 7:321-326.

11. Schwab RA & Bachhuber BH: Delirium and lactic acidosis caused by ethanol and niacin co-ingestion. Am J Emerg Med 1991; 9:363-365.

12. Figge HL, Figge J, Souney PF et al: Nicotinic acid: a review of its clinical use in the treatment of lipid disorders. Pharmacotherapy 1988; 8:287-294.

13. Product Information: Niaspan(R), niacin, extended release tablet. Kos Pharmaceuticals, Miami, FL; 1997.

14. Donowitz M, Wicks J & Sharp GW: Drug therapy for diarrheal diseases: a look ahead. Rev Infect Dis 1986; 8(suppl 2): S18-S20.

15. O'Hara JO, Jolly PN, Nicol CG: The therapeutic efficacy of inositol nicotinate (Hexopal(R)) in intermittent claudication: a controlled trial. Br J Clin Pract 1988; 42(9): 377-383.

16. Jonas WB, Rapoza CP & Blair WF: The effect of niacinamide on osteoarthritis: a pilot study. Inflamm Res 1996; 45(7): 330-334.

17. Pasternak RC, Brown LE, Stone PH et al: Effect of combination therapy with lipid-reducing drugs in patients with coronary heart disease and "normal" cholesterol levels: a randomized, placebo-controlled trial: Harvard Atherosclerosis Reversibility Project (HARP) study group. Ann Intern Med 1996; 125(7): 529-540.

18. Ding RW, Kolbe K, Merz B et al: Pharmacokinetics of nicotinic acid-salicylic acid interaction. Clin Pharmacol Ther 19889; 46(6): 642-647.

19. Anon: Lipid-lowering drugs. Med Lett Drugs Ther 1985; 27(695): 74-76.

20. Anon: Chaparral-induced toxic hepatitis - California and Texas, 1992. MMWR 1992; 41(43):812-814.

21. Anderson PC & McLean AEM: Comfrey and liver damage. Hum Toxicol 1989; 8:68-69.

22. Larrey D, Vial T, Pauwels A et al: Hepatitis after germander (Teucrium chamaedrys) administration: another instance of herbal medicine hepatotoxicity. Ann Intern Med 1992; 117:129-132.

23. Garg A & Grundy SM: Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990; 264(6):723-726.

24.Bennett WM, Aronoff GR, Golper TA et al: Drug prescribing in Renal Failure, 3rd ed. American College of Physicians, Philadelphia, PA, 1994.

25. Huxtable RJ: The myth of beneficent nature: the risks of herbal preparations Ann Intern Med 1992; 117:165-166.

26. Smith LW & Culvenor CCJ: Plant sources of hepatotoxic pyrrolizidine alkaloids. J Nat Products 1981; 44(2):129-152.

27. NIACOR(R), niacin (niacinamide). Upsher-Smith Laboratories, Minneapolis, MN, Feb 2000.

28. Product Information: Livalo oral film coated tablet, pitavastatin oral film coated tablet. Patheon Inc., Cincinnati, OH, 2009.

29. Christopher A: Critically elevated INR in a patient on warfarin after increase in extended-release niacin dose. Ann Pharmacother Nov, 2011; 45(11):e58.

Last Updated: 6/4/2018
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