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niacin (Oral route)



Commonly used brand name(s)

In the U.S.

  • Niacinol
  • Niacor
  • Niaspan
  • Nicotinex
  • Slo-Niacin

Available Dosage Forms:

  • Tablet
  • Tablet, Extended Release
  • Capsule
  • Capsule, Extended Release
  • Elixir

Therapeutic Class: Antihyperlipidemic

Pharmacologic Class: Vitamin B (class)

Chemical Class: Nicotinic Acid (class)

Uses For niacin

Niacin is used alone or with other medicines to treat high cholesterol and triglyceride (fat-like substances) levels in the blood. This may help prevent the development of pancreatitis (inflammation of the pancreas) and other problems caused by high levels of cholesterol and triglycerides in the blood. Niacin is also used to help lower risk of heart attack in patients with a history of heart attack and hyperlipidemia.

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niacin is available only with your doctor's prescription.

Before Using niacin

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For niacin, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to niacin or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of niacin extended-release tablets in children. However, safety and efficacy have not been established in children 16 years of age and younger.

There is no specific information comparing the use of niacin for high cholesterol in children with use in other age groups. However, use is not recommended in children under 2 years of age since cholesterol is needed for normal development.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of niacin extended-release tablets in the elderly.


Pregnancy Category Explanation
All Trimesters C Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking niacin, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using niacin with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Atorvastatin
  • Cerivastatin
  • Lovastatin
  • Pitavastatin
  • Rosuvastatin
  • Simvastatin

Using niacin with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using niacin with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use niacin, or give you special instructions about the use of food, alcohol, or tobacco.

  • Ethanol

Other Medical Problems

The presence of other medical problems may affect the use of niacin. Make sure you tell your doctor if you have any other medical problems, especially:

  • Alcohol, excessive use or
  • Angina (severe chest pain) or
  • Glaucoma or
  • Gout or
  • Heart attack, acute or
  • Heart disease or
  • Hypotension (low blood pressure) or
  • Jaundice, history of or
  • Kidney disease or
  • Muscle pain or tenderness, history of or
  • Muscle weakness, history of or
  • Stomach ulcers, history of—Use with caution. May make these conditions worse.
  • Bleeding problems or
  • Liver disease or
  • Stomach ulcers—Should not be used in patients with these conditions.
  • Diabetes or
  • Hypothyroidism (underactive thyroid) or
  • Kidney failure—Use with caution. May cause side effects to become worse.

Proper Use of niacin

Use niacin only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. To do so may increase the chance of unwanted effects.

niacin should come with a patient information insert. Read and follow these instructions carefully. Ask your doctor if you have any questions.

Remember that niacin will not cure your condition but it does help control it. You must continue to take it as directed if you expect to keep your cholesterol levels down.

Carefully follow the special diet your doctor gave you. This is the most important part of controlling your condition, and is necessary if the medicine is to work properly.

If niacin upsets your stomach, it may be taken with meals or milk. If stomach upset continues, check with your doctor.

For patients taking the extended-release capsules:

  • Swallow the capsule whole. Do not crush, break, or chew it. If the capsule is too large to swallow, you may mix the contents of the capsule with jam or jelly and swallow without chewing.

For patients taking the extended-release tablets:

  • Swallow the tablet whole. If the tablet is scored, it may be broken, but not crushed or chewed, before being swallowed.
  • Niaspan® should be taken at bedtime after a low-fat snack.
  • To decrease flushing or redness of your face, take aspirin or ibuprofen (eg, Advil®, Motrin®) 30 minutes before taking Niaspan®.
  • Avoid drinking alcohol or hot drinks or eating spicy foods around the time you take Niaspan®. This helps decrease flushing of your face.
  • If you stop taking niacin for any period of time, contact your doctor prior to restarting taking niacin.

If you are also using cholestyramine, colestipol, or colesevelam, you must take niacin 4 to 6 hours after you take these medicines.


The dose of niacin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of niacin. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For high cholesterol and triglycerides:
    • For oral dosage forms (extended-release capsules, oral solution, or regular tablets):
      • Adults—500 to 2000 milligrams (mg) one to three times a day.
      • Children—Use and dose must be determined by your doctor.
    • For oral dosage form (extended-release tablets):
      • Adults and children older than 16 years of age—At first, 500 milligrams (mg) per day, taken at bedtime. After 4 weeks, your doctor will increase your dose to 1000 mg per day, taken at bedtime. However, the dose is usually not more than 2000 mg per day.
      • Children 16 years of age and younger—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of niacin, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions While Using niacin

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly to lower your cholesterol and triglycerides and if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

Check with your doctor right away if you have dark-colored urine, diarrhea, a fever, muscle cramps or spasms, muscle pain or stiffness, or feel very tired or weak. These could be symptoms of a serious muscle problem called rhabdomyolysis, which can cause kidney problems.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. These could be symptoms of a serious liver problem.

niacin may affect blood sugar levels. If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

niacin may cause you to feel dizzy or faint, especially when you get up from a lying or sitting position. Getting up slowly may help. This effect should lessen after a week or two as your body gets used to the medicine. However, if the problem continues or gets worse, check with your doctor.

Do not stop taking niacin without first checking with your doctor. When you stop taking niacin, your blood cholesterol levels may increase again. Your doctor may want you to follow a special diet to help prevent this from happening.

Before you have any medical tests, tell the medical doctor in charge that you are taking niacin. The results of some tests may be affected by niacin.

Do not take vitamins or other dietary supplements unless they have been discussed with your doctor. This especially includes vitamins or dietary supplements that contain niacin or similar ingredients.

niacin Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common
  • Darkening of urine
  • light gray-colored stools
  • loss of appetite
  • severe stomach pain
  • yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common
  • Abdominal or stomach pain
  • cough
  • diarrhea
  • feeling of warmth
  • flushing or redness of the skin, especially on the face and neck
  • headache
  • nausea or vomiting
  • rash or itching
  • runny nose
  • sneezing
  • stuffy nose
Incidence not known
  • Dizziness or faintness
  • dryness of the skin
  • fever
  • frequent urination
  • joint pain
  • muscle aching or cramping
  • side, lower back, or stomach pain
  • swelling of the feet or lower legs
  • unusual thirst
  • unusual tiredness or weakness
  • unusually fast, slow, or irregular heartbeat

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

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