Niacin

A to Z Drug Facts

 Actions Necessary for lipid metabolism, tissue respiration and glycogenolysis. At pharmacologic doses, it reduces total cholesterol, LDL cholesterol, and triglycerides while increasing HDL cholesterol. Also causes peripheral vasodilation, especially cutaneous vessels.

 Indications Prevention and treatment of niacin deficiency or pellagra; treatment of hyperlipidemia (types IV and V); adjunct to diet for the reduction of elevated total and LDL levels in patients with primary hypercholesterolemia when the response to diet and other nonpharmacologic measures alone has been inadequate.

 Contraindications Significant liver disease; active peptic ulcer; severe hypotension; arterial hemorrhaging.

 Route/Dosage

Pellagra: ADULTS: PO Up to 500 mg daily in divided doses. Slow IV/SC/IM When oral route is not possible. Dietary Supplementation: ADULTS: PO RDA is 15 to 20 mg/day for adult men and 13 to 15 mg/day for adult women. Increase niacin to 17 to 20 mg/day during pregnancy and lactation. CHILDREN: PO RDA is 5 to 20 mg/day. Hyperlipidemia: ADULTS: PO Extended release: 500 mg at bedtime for 1 to 4 wk, then 1000 mg at bedtime during wk 5 to 8. If response is inadequate and patient tolerates dose, the dose may be increased by no more than 500 mg in a 4-wk period (max, 2000 mg/day). Immediate release: Initiate therapy at 250 mg with evening meal. The frequency of dose and total daily dose can be increased every 4 to 7 days until a dose of 1.5 to 2 g/day (in divided doses) is reached. If hyperlipidemia is not adequately controlled after 2 mo, increase dosage at 2- to 4-wk intervals to 1 g tid (max, 6 g/day).

 Interactions

Adrenergic-blocking agent: May potentiate hypotensive effect. HMG-CoA reductase inhibitors: Increased risk of myopathy and rhabdomyolysis.

 Lab Test Interferences May produce fluorescent substances, which may cause false elevation in some fluorometric measurements of urinary catecholamines. May produce false-positive reaction with cupric sulfate solution used for urinary glucose determination.

 Adverse Reactions

CARDIOVASCULAR: Hypotension; tachycardia. CNS: Dizziness; syncope; headache. DERMATOLOGIC: Flushing; pruritus; burning or tingling sensation; rash; hyperpigmentation (acanthosis nigricans); dry skin. EENT: Blurred vision; xerostomia. GI: Nausea; bloating; flatulence; hunger; vomiting; heartburn; diarrhea; activation of peptic ulcer; abdominal pain; dyspepsia. HEPATIC: Jaundice; liver damage; abnormal LFT results. OTHER: Hyperuricemia; hyperglycemia; decreased glucose tolerance test results; toxic amblyopia; atrial fibrillation and other cardiac arrhythmias; cystoid macular edema; orthostasis.

 Precautions

Pregnancy: Category A. (Category C if used in doses above RDA.) Lactation: Actively excreted in breast milk. CHILDREN: Safety and efficacy not established for doses exceeding nutritional requirements. Extended-release preparations not recommended for children. Special risk patients: Use drug with caution when administering to patients with gallbladder disease, history of jaundice, diabetes mellitus, gout, peptic ulcer, or allergy. Also, patients allergic to aspirin may be allergic to this product. Flushing: Commonly appears with oral therapy. Aspirin (325 mg) 30 min to 1 hr before niacin may decrease flushing. Long-acting dosage form: Increases risk of jaundice and hepatitis. Avoid use if possible. Heart disease: People who have recurrent chest pain (angina) or who recently suffered a heart attack should take niacin only under the supervision of a health care provider. Tartrazine sensitivity: Products containing FD&C yellow #5 may cause asthma in susceptible patients.

 Administration/Storage

• When giving orally, start with small doses, then increase gradually.
• Administer with food.
• Do not crush or break oral medication.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• If giving for hyperlipidemia, check baseline and monitor cholesterol level.
• Check blood glucose, LFTs, and uric acid level as ordered.
• Monitor vital signs.
• Assess for signs of jaundice, light-colored stools, dizziness, or faint feeling.
• Notify health care provider of changes from baseline assessment.

 Patient/Family Education

• Tell patient not to break up medication if taking orally.
• Explain that flushing may appear after taking medication but should dissipate with continued therapy.
• Tell patient to take medication with food.
• Identify specific elements of well-balanced, low-fat diet.
• Instruct patient to report the following symptoms to health care provider: jaundice, light-colored stools, excessive thirst, urinary frequency, dizziness, or faint feeling.
• Caution patient to avoid sudden position changes, especially lying to sitting, to prevent dizziness.
• Advise patient to avoid intake of alcoholic beverages or hot drinks and large doses of medication (more than 500 mg) at one time to minimize flushing and warmth sensation.
• Advise diabetic patients to notify health care provider if a change in blood glucose occurs.
• Instruct patient to inform health care provider if taking vitamins or other nutritional supplements containing niacin or a related compound such as nicotinamide.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts