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).
Niacin may also be used for purposes not listed in this medication guide.
Important information
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, or tingly feeling under your skin). 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. Get up slowly and steady yourself to prevent a fall.
Avoid taking colestipol (Colestid) or cholestyramine (Locholest, Prevalite, Questran) 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.
Before taking this medicine
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.
To make sure you can safely take niacin, tell your doctor if you have any of these other conditions:
FDA pregnancy category C. Niacin may be harmful to an unborn baby when the medication is taken at doses to treat high cholesterol or other conditions. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Niacin can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.
See also: Pregnancy and breastfeeding warnings (in more detail)
How should I take niacin ?
Use niacin exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.
Niacin is sometimes taken at bedtime with a low-fat snack. Follow your doctor"s instructions.
Niacin can cause certain side effects, such as flushing (warmth, itching, redness, or tingly feeling under your skin). 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.
Take niacin with a full glass of cold or cool water. Taking the medication with a hot drink may increase your risk of side effects such as flushing. Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time. Extended-release tablets and capsules contain higher strengths of the medicine than the regular tablets. Take only the dose that is correct for the type of niacin tablet or capsule you are using.
Niacin can cause you to have unusual results with certain medical tests (urine tests). Tell any doctor who treats you that you are using this medicine.
If you stop taking niacin for any length of time, talk with your doctor before starting the medication again. You may need to restart the medication at a lower dose.
While using niacin, you may need blood tests at your doctor"s office. Your kidney or liver function may also need to be checked. Visit your doctor regularly.
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.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Be sure to take the missed dose with food if you normally take your niacin dose with a meal or snack.
Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include nausea, dizziness, itching, vomiting, upset stomach, and flushing (warmth, redness, or tingly feeling).
What should I avoid?
Avoid drinking hot beverages shortly after taking niacin. Hot drinks can worsen the flushing effect (warmth, itching, redness, or tingly feeling under your skin).
Avoid drinking alcohol while taking niacin. Alcohol may increase your risk of liver damage, and can also worsen the flushing effects of this medicine.
Avoid taking colestipol (Colestid) or cholestyramine (Locholest, Prevalite, Questran) 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 niacin.
Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
Niacin side effects
Get emergency medical help if you have any of these signs of an allergic reaction to niacin: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have any of these serious side effects:
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feeling like you might pass out;
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fast, pounding, or uneven heart beats;
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feeling short of breath;
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swelling;
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jaundice (yellowing of your skin or eyes); or
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muscle pain, tenderness, or weakness with fever or flu symptoms and dark colored urine.
If you are diabetic, tell your doctor about any changes in your blood sugar levels.
Less serious side effects of niacin include:
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mild dizziness;
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warmth, redness, or tingly feeling under your skin;
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itching, dry skin;
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sweating or chills;
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nausea, diarrhea, belching, gas;
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muscle pain, leg cramps; or
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sleep problems (insomnia).
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
Niacin dosing information
Usual Adult Dose for Hyperlipoproteinemia Type IV (Elevated VLDL):
Initial dose: 100 mg orally 3 times a day, with or after meals.
Maintenance dose: 1 to 2 g orally 3 times a day, with or after meals.
The maximum recommended dose is 6 g/day.
Extended Release (Niaspan):
Initial dose: 500 mg orally once a day at bedtime after a low fat snack. Maximum recommended dose is 2 g/day.
Extended Release (Slo-Niacin):
Initial dose: 250 to 750 mg orally once a day morning or evening.
Usual Adult Dose for Hyperlipoproteinemia Type V (Elevated Chylomicrons + VLDL):
Initial dose: 100 mg orally 3 times a day, with or after meals.
Maintenance dose: 1 to 2 g orally 3 times a day, with or after meals.
The maximum recommended dose is 6 g/day.
Extended Release (Niaspan):
Initial dose: 500 mg orally once a day at bedtime after a low fat snack. Maximum recommended dose is 2 g/day.
Extended Release (Slo-Niacin):
Initial dose: 250 to 750 mg orally once a day morning or evening.
Usual Adult Dose for Pellagra:
50 to 100 mg orally 3 to 4 times a day.
The maximum recommended dose is 500 mg orally each day.
Usual Adult Dose for Niacin Deficiency:
10 to 20 mg orally once a day. Niacin may also be administered parenterally as a component of injectable multivitamin additives contained in parenteral nutrition products.
The maximum recommended dose is 100 mg orally each day.
Usual Pediatric Dose for Pellagra:
50 to 100 mg orally 3 times daily.
Note: Some experts prefer niacinamide for treatment due to a more favorable side effect profile.
Usual Pediatric Dose for Niacin Deficiency:
Dosages are Recommended Daily Allowances (RDA):
1 to 5 months: 2 mg orally each day.
6 to 11 months: 3 mg orally each day.
1 to 3 years: 6 mg orally each day.
4 to 8 years: 8 mg orally each day.
9 to 13 years: 12 mg orally each day.
Males:
14 to 18 years: 16 mg orally each day.
Females:
14 to 18 years: 14 mg orally each day.
Niacin may also be administered parenterally as a component injectable multivitamin additives contained in parenteral nutrition products.
What other drugs will affect niacin?
Tell your doctor about all other cholesterol-lowering drugs you are taking with niacin, especially atorvastatin (Lipitor, Caduet), fluvastatin (Lescol), lovastatin (Mevacor, Altoprev, Advicor), pravastatin (Pravachol), or simvastatin (Zocor, Simcor, Vytorin, Juvisync).
Ask a doctor or pharmacist if it is safe for you to use niacin if you are also using any of the following drugs:
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a blood thinner such as warfarin (Coumadin, Jantoven);
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multivitamins or mineral supplements that contain niacin;
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blood pressure or heart medications such as amlodipine (Norvasc, Caduet, Exforge, Lotrel, Tekamlo, Tribenzor, Twynsta, Amturnide), diltiazem (Cardizem, Cartia, Dilacor, Diltia, Diltzac, Taztia, Tiazac), felodipine (Plendil), nicardipine (Cardene), nifedipine (Procardia, Adalat), nimodipine (Nimotop), nisoldipine (Sular), or verapamil (Calan, Covera, Isoptin, Verelan); or
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heart medications such as doxazosin (Cardura), isosorbide (Dilatrate, Imdur, Isordil, Monoket, Sorbitrate), nitroglycerin (Nitro-Bid, Nitro-Dur, Nitrostat), prazosin (Minipress), or terazosin (Hytrin).
This list is not complete and other drugs may interact with niacin. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.
