What is the typical dosage of niacin (Vitamin B3) for managing high cholesterol in adults?

Niacin Dosing for High Cholesterol Management

For managing high cholesterol in adults, niacin should be started at a low dose of 500 mg daily at bedtime and gradually titrated to a maximum of 2,000 mg daily, with extended-release niacin increasing by no more than 500 mg every 4 weeks. 1

Dosing Recommendations

Initial Dosing and Titration

• Start with 500 mg at bedtime for 4 weeks 1, 2
• Increase by 500 mg every 4 weeks as tolerated 1, 2
• Maximum recommended dose: 2,000 mg daily 1, 2

Formulation-Specific Dosing

• Extended-release niacin (preferred):

  • Start at 500 mg at bedtime
  • Increase from 500 mg to maximum 2,000 mg/day over 4-8 weeks
  • Dose should not increase more than weekly 1

• Immediate-release niacin:

  • Start at 100 mg 3 times daily
  • Up-titrate to 3 g/day, divided into 2-3 doses 1

Monitoring and Safety

Baseline testing before initiating niacin therapy should include:

• Hepatic transaminases
• Fasting blood glucose or hemoglobin A1c
• Uric acid 1

These tests should be repeated during dose up-titration and every 6 months thereafter 1.

Contraindications

Niacin should not be used in patients with:

• Hepatic transaminase elevations higher than 2-3 times upper limit of normal
• Persistent severe cutaneous symptoms
• Persistent hyperglycemia
• Acute gout
• Unexplained abdominal pain or gastrointestinal symptoms
• New-onset atrial fibrillation or weight loss 1

Efficacy by Dose

Niacin demonstrates dose-dependent effects on lipid parameters:

• At 1,000 mg/day: 7% reduction in LDL-C, 14% increase in HDL-C, 16% reduction in triglycerides 2
• At 1,500 mg/day: 13% reduction in LDL-C, 19% increase in HDL-C, 25% reduction in triglycerides 2
• At 2,000 mg/day: 16% reduction in LDL-C, 22% increase in HDL-C, 38% reduction in triglycerides 2

Gender Differences

Women may respond at lower doses than men but may also experience more side effects 2, 3. Consider using lower doses in women while still achieving therapeutic goals 3.

Managing Side Effects

To reduce flushing and other cutaneous symptoms:

• Take niacin with food or a low-fat snack at bedtime 1, 2
• Premedicate with aspirin 325 mg 30 minutes before niacin dosing 1
• Start at a low dose and titrate slowly 1

Formulation Considerations

Extended-release niacin is preferred over sustained-release formulations due to:

• Better safety profile, particularly regarding hepatotoxicity 4
• Once-daily dosing convenience 3, 5
• Similar efficacy to immediate-release preparations 5

Important Cautions

• Sustained-release niacin formulations have been associated with higher rates of hepatotoxicity (52% in one study) compared to immediate-release formulations and should be restricted from use 4
• Never substitute equivalent doses of immediate-release niacin with extended-release preparations without proper titration 2
• Monitor for potential adverse effects including flushing, pruritus, hyperglycemia, and elevated liver enzymes 1, 2

Niacin remains an effective option for managing dyslipidemia, particularly for patients who need increases in HDL-C along with reductions in LDL-C, triglycerides, and lipoprotein(a) 2, 6.