niacin (vitamin B3, Niacor, Niaspan, nicotinic acid)
Classes: Lipid-Lowering Agents, Other; B Vitamins; Vitamins, Water-Soluble
Dosing and uses of Vitamin B3, Niacor (niacin)
Adult dosage forms and strengths
tablet
- 50mg
- 100mg
- 250mg
- 500mg
tablet, extended-release
- 250mg
- 500mg
- 750mg
- 1000mg
capsule extended-release
- 250mg
- 500mg
Nutritional Supplementation
Recommended daily allowance (RDA)
Males: ≥19 years: 16 mg/day
Females: ≥19 years: 14 mg/day
Pregnant women: 18 mg/day
Breastfeeding: 17 mg/day
Dietary supplement (OTC)
50 mg PO q12hr or 100 mg PO qDay; many formulations exist
Hyperlipidemia
Immediate-release: 250 mg PO once daily; dose or frequency adjusted every 4-7 days on basis of effect and tolerance to first-level therapeutic dose of 1.5-2 g PO divided q6-8hr, then adjusted every 2-4 weeks; not to exceed 6 g/day
Extended-release: 500 mg/day PO at bedtime initially; dose adjusted every 4 weeks on basis of effect and tolerance to therapeutic dose of 1-2 g once daily; not to exceed 1-2 g/day
Indications
- Reduce elevated TC, LDL-C, Apo B and TG levels, and to increase HDL-C in patients with primary hyperlipidemia and mixed dyslipidemia
- Indicated to reduce the risk of recurrent nonfatal myocardial infarction in patients with history of MI and hyperlipidemia
- Indicated in combination with a bile acid binding resin to slow progression or promote regression of atherosclerotic disease in patients with history of CAD and hyperlipidemia, and also to reduce elevated TC and LDL-C levels in adults with primary hyperlipidemia
- Indicated as adjunctive therapy for treatment of adult patients with severe hypertriglyceridemia who present a risk of pancreatitis and who do not respond adequately to a determined dietary effort to control them
- Extended release niacin did not reduce cardiovascular morbidity or mortality among patients treated with simvastatin in a large rantomized trial
Dosing Considerations
Limitations of use: Extended-release niacin did not reduce cardiovascular morbidity or mortality among patients treated with simvastatin in a large rantomized triaL
Nonsteroidal anti-inflammatory drug (NSAID) will decrease flushing when administered 30-60 minutes before dosing
Monitor liver function tests (LFTs)
Indication for use with statins withdrawn by FDA
- April 15, 2016: Based on several large cardiovascular outcome trials including AIM-HIGH, ACCORD, and HPS2-THRIVE, the FDA decided that "scientific evidence no longer supports the conclusion that a drug-induced reduction in triglyceride levels and/or increase in HDL-cholesterol levels in statin-treated patients results in a reduction in the risk of cardiovascular events"
- Consistent with this conclusion, the FDA has determined that the benefits of niacin ER tablets for coadministration with statins no longer outweigh the risks, and the approval for this indication should be withdrawn
Overdose management
- Symptoms of acute overdose include flushing, GI distress, and pruritus
- Chronic overdose has been associated with hepatitis
- Treatment is symptomatic
Pellagra (Off-label)
50-100 mg PO q6-8hr; not to exceed 500 mg/day
Pediatric dosage forms and strengths
tablet
- 50mg
- 100mg
- 250mg
- 500mg
tablet, extended-release
- 250mg
- 500mg
- 750mg
- 1000mg
capsule extended-release
- 250mg
- 500mg
Nutritional Supplementation
RDA
0-6 months: 2 mg/day
6-12 months: 3 mg/day
1-4 years: 6 mg/day
4-9 years: 8 mg/day
9-14 years: 12 mg/day
14-18 years: 16 mg/day (boys); 14 mg/day (girls)
Pellagra (Off-label)
50-100 mg PO q8hr
Monitor LFTs
Vitamin B3, Niacor (niacin) adverse (side) effects
Frequency not defined
Reversible increase in serum aminotransferase
Flushing (lower incidence with extended-release products)
Pruritus, rash
Diarrhea
Headache
Arrhythmias
Hepatic necrosis, hepatotoxicity (higher incidence with extended-release products)
Postural hypotension
Rhabdomyolysis
Abdominal pain
Dyspepsia
Nausea
Vomiting
Postmarketing Reports
Burning sensation of skin
Depression
Dermatomyositis
Peripheral nerve palsy
Progression of cataracts
Warnings
Contraindications
Hypersensitivity
Hepatic disease, active peptic ulcer, severe hypotension, arterial bleeding
Persistent, unexplained elevation of serum aminotransferase
Cautions
Flushing or pruritus may occur
Hepatotoxicity reported
Use with caution in patients with history of liver disease, gout or gouty diathesis, diabetes mellitus, gallbladder disease, cardiovascular disease, or renal or hepatic impairment
Use with caution if patients are taking anticoagulants or HMG-CoA reductase inhibitors or if symptoms of myopathy occur (monitor creatine phosphokinase)
Immediate release and extended release dosage forms are not interchangeable
Pregnancy and lactation
Pregnancy category: A; C (for doses exceeding RDA)
Lactation: Unknown if excreted in milk (consider risk vs benefit)
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Vitamin B3, Niacor (niacin)
Mechanism of action
Component of two coenzymes necessary for lipid metabolism, tissue respiration, glycogenolysis, inhibition of very low-density lipoprotein (VLDL) synthesis
May increaase chylomicron triglyceride removal from plasma
Absorption
Rapidly absorbed (60-76%)
Peak plasma time: Immediate release, 30-60 min; extended release, 4-5 hr
Metabolism
Metabolized in liver
Pharmacokinetics
Half-life: 20-45 min
Excretion: Urine (60-88% as unchanged drug)
