Drug information of Nicotinic acid
Niacin, also called nicotinic acid, is a B vitamin (vitamin B3). It occurs naturally in plants and animals, and is also added to many foods as a vitamin supplement. It is also present in many multiple vitamins and nutritional supplements.
Niacin is used to treat and prevent a lack of natural niacin in the body, and to lower cholesterol and triglycerides (types of fat) in the blood. It is also used to lower the risk of heart attack in people with high cholesterol who have already had a heart attack. It is sometimes used to treat coronary artery disease (also called atherosclerosis).
Therapy with lipid-altering agents should be only one component of multiple risk factor intervention in individuals at significantly increased risk for atherosclerotic vascular disease due to hyperlipidemia. Niacin therapy is indicated as an adjunct to diet when the response to a diet restricted in saturated fat and cholesterol and other nonpharmacologic measures alone has been inadequate.
Mechanism of effect
Niacin (nicotinic acid) is bioconverted to nicotinamide which is further converted to nicotinamide adenine dinucleotide (NAD+) and the hydride equivalent (NADH) which are
coenzymes necessary for tissue metabolism, lipid metabolism, and glycogenolysis. The mechanism by which niacin (in lipid-lowering doses) affects
plasma lipoproteins is not fully understood. It may involve several actions including partial inhibition of release of free fatty acids from adipose tissue, and increased lipoprotein lipase
activity, which may increase the rate of chylomicron triglyceride removal from plasma. Ultimately, niacin reduces total cholesterol, apolipoprotein (apo) B, triglycerides, VLDL, LDL,
lipoprotein (a), and increases HDL and other important components and subfractions (eg, LPA-I)
Absorption: Immediate release formulation: Rapid and extensive. Protein binding: <20% bound to serum proteins
Metabolism: Extensive first-pass metabolism; converted to nicotinamide adenine dinucleotide, nicotinuric acid (after conjugation with glycine), and other metabolites. At doses used to
treat hyperlipidemia, metabolic pathways are saturable.
Half-life elimination: 20 to 48 minutes
Time to peak, serum: Immediate release formulation: 30 to 60 minutes; extended release formulation: 4 to 5 hours
Excretion: Urine 60% to 88% (unchanged drug [up to 12% recovered after multiple dosing] and metabolites)
Note: Formulations of niacin (regular release versus extended release) are not interchangeable.
Recommended daily allowances: Oral:
≥19 years: Females: 14 mg daily; Males: 16 mg daily
Pregnancy (all ages): 18 mg daily
Lactation (all ages): 17 mg daily
Dietary supplement (OTC labeling): Oral: 50 mg twice daily or 100 mg once daily.
Regular release formulation (Niacor): Initial: 250 mg once daily (with evening meal); increase frequency and/or dose every 4 to 7 days to desired response or first-level therapeutic
dose (1.5 to 2 g daily in 2 to 3 divided doses); after 2 months, may increase at 2- to 4-week intervals to 3 g daily in 3 divided doses (maximum dose: 6 g daily in 3 divided
Sustained release (or controlled release) formulations: Usual dosage is 250 to 750 mg once daily, taken morning or
evening, or as directed. Before using more than 500 mg daily, patient should consult health care provider.
Extended release formulation (Niaspan): Initial: 500 mg at bedtime for 4 weeks, then 1 g at bedtime for 4 weeks; adjust dose to response and tolerance; may increase daily dose
every 4 weeks by not more than 500 mg daily to a maximum of 2 g daily. Recommended maintenance dose: 1,000 to 2,000 mg at bedtime.
Pellagra (off-label use): Oral: 50 to 100 mg 3 to 4 times daily; maximum: 500 mg daily .Some experts
prefer niacinamide for treatment due to more favorable side effect profile.
Drug contraindicationshypersensitivity to this drug
Side effectsDiarrhea , Headache , nausea , vomiting , dyspepsia , itching , skin rash , Abdominal pain , Rash
InteractionsHydroxyprogesterone Caproate , Aspirin , Glipizide , Mitiglinide , Cerivastatin
- Flushing/pruritus: Flushing and pruritus, common adverse effects of niacin, may be attenuated with a gradual increase in dose, administering with food, avoidance of concurrent
ingestion of ethanol or hot liquids, and/or by taking aspirin (adults: 325 mg) 30 minutes before dosing
. Flushing associated with extended release preparation is significantly reduced. For immediate release preparations, may administer in 2 to 3
divided doses to reduce the frequency and severity. Niacin should not be used if patient experiences persistent severe cutaneous symptoms during therapy.
- May cause gastrointestinal distress, vomiting, diarrhea, or aggravate peptic ulcer; gastrointestinal distress may be attenuated with a gradual increase in
dose and administration with food. Use is contraindicated in patients with active peptic ulcer disease; use with caution in patients with a past history of peptic ulcer. Niacin
should not be used if patient experiences unexplained abdominal pain or gastrointestinal symptoms or unexplained weight loss during therapy .
- Hematologic effects: Dose-related reductions in platelet count and increases of prothrombin time may occur
- Hepatotoxicity: Cases of severe hepatotoxicity, including fulminant hepatic necrosis, have occurred when immediate release (crystalline) niacin products have been substituted
with sustained-release (modified release, timed-release) niacin products at equivalent doses. Patients should be initiated with low doses (eg, niacin extended-release 500 mg at
bedtime) with titration to achieve desired response. Liver function tests should be monitored in all patients receiving lipid-lowering doses of niacin. Niacin should not be used
if hepatic transaminase elevations >2 to 3 times upper limit of normal occur during therapy
- Hypophosphatemia: Has been associated with small but statistically significant dose-related reductions in phosphorus levels. Monitor phosphorus levels periodically in patients at
risk for hypophosphatemia.
- Cardiovascular disease: Use with caution in patients with unstable angina or in the acute phase of an MI.
- Diabetes: Niacin may increase fasting blood glucose. Use niacin with caution in patients
with diabetes. adjustment of diet and/or hypoglycemic therapy may be necessary. Niacin should not be used if patient experiences persistent hyperglycemia
- Gout: May be associated with hyperuricemia. Use with caution in patients predisposed to gout. Niacin should not be used if patient experiences acute gout during therapy.
- Hepatic impairment: Use with caution in patients with a past history of hepatic impairment; monitor liver function tests. Contraindicated with active liver disease or unexplained
persistent transaminase elevation.
- Renal impairment: Use with caution in patients with renal impairment.
- Alcohol use: Use with caution in patients who consume large amounts of ethanol due to the increased risk of liver dysfunction.
Points of recommendation
You should not take this medication if you are allergic to niacin, or if you have severe liver disease, a stomach ulcer, or active bleeding.
Niacin can cause certain side effects, such as flushing (warmth, itching, redness). These effects can be made worse if you drink alcohol or hot beverages shortly after you take niacin. These effects should disappear over time as you keep taking the medication.
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.
Avoid taking colestipol or cholestyramine at the same time you take niacin. If you take either of these other medications, take them at least 4 to 6 hours before or after you take this medicine.
Niacin is only part of a complete program of treatment that may also include diet, exercise, weight control, and other medications. Follow your diet, medication, and exercise routines very closely.
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