Niacin

Summary

Niacin, also known as vitamin B3, is a lipid-lowering drug used to treat patients with hyperlipidemia. Niacin works by reducing hepatic VLDL synthesis and inhibiting lipolysis in adipose tissue. In laboratory testing, niacin causes a great rise in HDL levels, a great fall in LDL levels, and a fall in triglyceride levels. Side effects of niacin include flushing, which is caused by prostaglandins. This flushing may be prevented or treated with NSAIDs. Other side effects of taking niacin include hyperglycemia and hyperuricemia.

Key Points

• Niacin (Vitamin B3)
  • Clinical Use
    • Lipid Lowering drug
      • Generally used to treat hyperlipidemia by lowering cholesterol levels.
  • Mechanism
    • Inhibits lipolysis in adipose tissue
    • Reduces hepatic VLDL synthesis
  • Labs
    • ↓↓ LDL
    • ↑↑ HDL
      • Niacin is one of the more effective agents for raising HDL levels; most other agents work to reduce LDL levels
    • ↓ Triglycerides
  • Side Effects
    • Flushing
      • Mediated by Prostaglandins
        • Treated by NSAIDs or long-term use
    • Hyperglycemia
      • Occurs during chronic and high-dose treatments, mechanism not well understood
    • Hyperuricemia
      • May occasionally increase plasma uric acid levels and induce gout
      • Mechanism not well understood; niacin may inhibit uricase, which normally breaks down uric acid