Medicine & USMLE

Nicotinic Acid (Niacin)

Cardio Drugs - Lipid Lowering
  1. Fibrates
  2. Statins
  3. Ezetimibe
  4. Nicotinic Acid (Niacin)
  5. Bile Acid Sequestrants


Nicotinic acid is a medication that is also referred to as niacin or vitamin B3.

It is a lipid-lowering drug used to treat patients with hyperlipidemia, and can also be given to treat patients with a vitamin B3 deficiency, called pellagra.

Nicotinic acid raises HDL levels, lowers LDL levels, and lowers triglyceride levels.

Nicotinic acid has several side effects, including flushing, which can be treated with NSAIDs. It also may cause itching and hyperglycemia. Patients taking nicotinic acid may experience nausea and vomiting, and should take the medication with food to minimize this side effect. Additional side effects include hepatotoxicity and hyperuricemia.

Key Points

  • Nicotinic Acid / Niacin (Vitamin B3)
    • Clinical Use
      • Lipid lowering drug
        • Also referred to as an “antilipemic”
        • Lowers cholesterol levels
      • Treats pellagra
        • Pellagra is a vitamin B3 deficiency
        • Symptoms of pellagra include diarrhea, dermatitis, and dementia.
    • Mechanism
      • Lowers LDL
        • LDL stands for low density lipoprotein
        • Often referred to as “bad” cholesterol
      • Raises HDL
        • HDL stands for high density lipoprotein
        • Often referred to as “good” cholesterol
        • Memory trick - think of H for Healthy!
      • Lowers triglycerides
        • A type of fat that circulates in the bloodstream
      • Decreases lipoprotein synthesis
        • Increases activity of lipase to breakdown lipids
      • Decreases liver production of VLDL
    • Side Effects
      • Nausea/Vomiting
        • As well as other GI side effects such as diarrhea
        • Take with food to help reduce GI side effects
      • Flushing
        • May last 1-2 hours
        • A common, expected side effect
        • NSAIDs (aspirin, ibuprofen, etc.) help prevent flushing
      • Hepatotoxicity
        • Monitor for elevated liver enzymes
        • Avoid alcohol
      • Hyperglycemia
        • Monitor blood sugar levels
      • Itching (pruritus)
      • Hyperuricemia
        • Increased uric acid levels in the blood
        • Puts patient at an increased risk for gout