Vitamin B3 (Niacin, Nicotinic Acid)

Category:

  • Vitamin

Description:

  • Dietary supplement; water-soluble vitamin

  Indications:

  • Vitamin B3 deficiency

    • necessary for cholesterol control, electron transfer

  • Pellegra (characterized by the three “Ds”: diarrhea, dermatitis, dementia)

  • Hyperlipidemia

Contraindications:

  • Hepatic dysfunction

  • Active peptic ulcer disease

Precautions:

  • Pregnancy category A, (pregnancy category C if given above RDA doses)

  • Do not administer with HMG-CoA reductase inhibitors (lovastatin, simvastatin, etc.) due to risk of rhabdomyolysis.

  • Monitor liver function tests and blood glucose (especially diabetic patients)

  • May increase uric acid levels and precipitate gout.

  • Flushing appears more frequently with oral therapy and generally occurs within the first two hours of administration.  Flushing may be decreased if 325mg aspirin is administered 30-60 minutes pre-niacin dosing.

Adverse Reactions (Side Effects):

  • Relatively non-toxic dietary doses

  • At higher doses:

    • facial and generalized flushing (within first 2 hours), rash, itching, dry skin, pruritis

    • GI distress, activation of peptic ulcers, nausea, vomiting, diarrhea

    • hepatotoxicity

Dosage:

  • Dietary sources: lean meat, fish, cereals, grains, legumes, conversion of dietary trytophan

  • Administered orally (tablets, capsules, sustained-release, elixir) or injection

  • Dietary supplementation (RDA: recommended daily allowance):

    • 6.6mg per 1000Kcal intake

    • Adult males: 19mg per day

    • Adults females: 15mg per day

  • Niacin deficiency: up to 100mg per day

  • Pellegra: up to 500mg per day

  • Hyperlipidemia: 1-2 grams tid (do not exceed 6 grams per day)

 
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