Niacin is used with diet changes (restriction of cholesterol and fat intake) to reduce the amount of cholesterol (a fat-like substance) and other fatty substances in your blood and to increase the amount of high density lipoprotein (HDL; ”good cholesterol”). Niacin can be used in a number of situations including the following:

• Alone or in combination with other medications, such as HMG-CoA inhibitors (statins) or bile acid-binding resins;
• To decrease the risk of another heart attack in patients with high cholesterol who have had a heart attack;
• To prevent worsening of atherosclerosis (buildup of cholesterol and fats along the walls of the blood vessels) in patients with high cholesterol and coronary artery disease;
• To reduce the amount of triglycerides (other fatty substances) in the blood in patients with very high triglycerides who are at risk of pancreatic disease (conditions affecting the pancreas, a gland that produces fluid to break down food and hormones to control blood sugar).

Niacin is also used to prevent and treat pellagra (niacin deficiency), a disease caused by inadequate diet and other medical problems. Niacin is a B-complex vitamin. At therapeutic doses, niacin is a cholesterol-lowering medication.

Results of a clinical study in people with heart disease and well-controlled cholesterol levels that compared people who took niacin and simvastatin with people who took simvastatin alone and found similar results for the two groups in the rate of heart attacks or strokes. Taking niacin along with simvastatin or lovastatin also has not been shown to reduce the risk of heart disease or death compared with the use of niacin, simvastatin, or lovastatin alone. Talk to your doctor if you have questions about the risks and benefits of treating increased amounts of cholesterol in your blood with niacin and other medications.

Niacin comes as a tablet and an extended-release (long-acting) tablet to take by mouth. The regular tablet usually is taken two to three times a day with meals, and the extended-release tablet is taken once a day, at bedtime, after a low-fat snack. Follow the directions on your prescription label or package label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take niacin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow the extended-release tablets whole; do not split, chew, or crush them.

Your doctor will probably start you on a low dose of niacin and gradually increase your dose.

Continue to take niacin even if you feel well. Do not stop taking niacin without talking to your doctor.

Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.

This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking niacin,

• Tell your doctor and pharmacist if you are allergic to niacin, any other medications, or any of the ingredients in niacin tablets. Ask your pharmacist or check the manufacturer’s information for the patient for a list of the ingredients.
• Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: anticoagulants (‘blood thinners’) such as warfarin (Coumadin); aspirin; insulin or oral medications for diabetes; medications for high blood pressure; nutritional supplements or other products containing niacin; or other medications for lowering cholesterol or triglycerides. If you take insulin or oral diabetes medication, your dose may need to be changed because niacin may increase the amount of sugar in your blood and urine.
• If you are taking a bile acid-binding resin such as colestipol (Colestid) or cholestyramine (Questran), take it at least 4 to 6 hours before or 4 to 6 hours after niacin.
• Tell your doctor if you drink large amounts of alcohol and if you have or have ever had diabetes; gout; ulcers; allergies; jaundice (yellowing of the skin or eyes); bleeding problems; or gallbladder, heart, kidney, or liver disease.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking niacin, stop taking niacin and call your doctor.
• If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking niacin.
• Ask your doctor about the safe use of alcoholic beverages while you are taking niacin. Alcohol can make the side effects from niacin worse.
• You should know that niacin causes flushing (redness, warmth, itching, tingling) of the face, neck, chest, or back. This side effect usually goes away after taking the medicine for several weeks. Avoid drinking alcohol or hot drinks or eating spicy foods around the time you take niacin. Taking aspirin or another nonsteroidal anti-inflammatory drug such as ibuprofen (Advil, Motrin) or naproxen (Aleve, Naprosyn) 30 minutes before niacin may reduce the flushing. If you take extended-release niacin at bedtime, the flushing will probably happen while you are asleep. If you wake up and feel flushed, get up slowly, especially if you feel dizzy or faint.

Eat a low-fat, low-cholesterol diet. Be sure to follow all exercise and dietary recommendations made by your doctor or dietitian. You can also visit the National Cholesterol Education Program (NCEP) website for additional dietary information at http://www.nhlbi.nih.gov/health/public/heart/chol/chol_tlc.pdf.

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

If you stop taking niacin for any length of time, call your doctor before you start taking it again.

Niacin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Diarrhea
• Increased cough

If you experience any of the following symptoms, call your doctor immediately or get emergency medical treatment:

• Dizziness
• Faintness
• Fast heartbeat
• Nausea
• Vomiting
• Extreme tiredness
• Dark colored urine
• Light colored stools
• Unusual bleeding or bruising
• Lack of energy
• Loss of appetite
• Pain in the upper right part of the stomach
• Yellowing of the skin or eyes
• Flu-like symptoms
• Hives
• Rash
• Itching
• Difficulty breathing or swallowing
• Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
• Hoarseness
• Unexplained muscle pain, tenderness, or weakness

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to niacin.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking niacin.

Only use the brand and type of niacin that your doctor prescribed. Do not use another brand of niacin or switch between products without talking to your doctor. If you switch to a different brand or type of niacin, your dose may need to be changed.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.