niacin (vitamin B3, Niacor, Niaspan, nicotinic acid)

Dosing and uses of Vitamin B3, Niacor (niacin)

• Adult
• Pediatric

 

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Indication for use with statins withdrawn by FDA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)