Nicotinic acid, commonly known as niacin, is a form of vitamin B3. It is a naturally occurring vitamin that may be used to treat high cholesterol. Niacin may be referred to as a cholesterol-reducing drug, even though it is available over-the-counter. As a supplement, it is not subject to the same government regulation as prescription or over-the-counter medications.

Other cholesterol-reducing medications include statins, fibrates and bile acid resins. While statins are the considered the first line of defense for treating high cholesterol, nicotinic acid is effective at lowering blood levels of triglycerides and increasing blood levels of HDL (or “good” cholesterol). At a higher dosage, nicotinic acid is also effective at lowering blood levels of LDL (or “bad” cholesterol). Nicotinic acid may sometimes be prescribed in addition to other cholesterol-reducing medications.

High levels of cholesterol, triglycerides and other fats in the bloodstream increase the risk of hardening of the arteries (atherosclerosis), heart attack, stroke and other heart-related conditions.

Nicotinic acid is available over-the-counter (as niacin), but physicians often prefer to prescribe it in time-released pills. Side effects include flushing or hot flashes, which can be intense at large doses. As with other medications and supplements, patients should consult a physician before taking niacin. In addition, patients who use nicotinic acid should be closely monitored by their physician to avoid complications.

Nicotinic acid (niacin) is a form of vitamin B3 found naturally in meat, eggs and dairy products. It is also available as an over-the-counter supplement as vitamin B3 or niacin. Niacin is sometimes used in the treatment of high cholesterol (hypercholesterolemia). Because of this, it is often referred to as a cholesterol-reducing drug, along with statins, fibrates and bile acid resins.

There are two main forms of vitamin B3: nicotinic acid (niacin) and nicotinamide (niacinamide). When these substances are taken in low doses for nutritional purposes, they are virtually identical. However, when taken in the high doses necessary for the treatment of high cholesterol, the effects of these two substances vary. Nicotinamide (niacinamide) in high doses is generally used for the prevention or early treatment of type 1 (child onset) diabetes and for the reduction of symptoms associated with osteoarthritis. In comparison, nicotinic acid (niacin) is preferred for high dose use in the treatment of high cholesterol. Nicotinamide should not be used as a substitute for nicotinic acid as it does not lower cholesterol levels.

A special form of niacin (inositol hexaniacinate or IHN) may also be used in the treatment of high cholesterol, as well as certain peripheral venous disorders (e.g., Raynaud syndrome, claudication).

While statins are considered the first line of defense for treating high cholesterol, nicotinic acid has shown an ability to increase blood levels of HDLs (or “good” cholesterol). Nicotinic acid is also highly effective in lowering blood levels of triglycerides and lipoprotein “a”. Lipoprotein “a” – abbreviated Lp(a) – is a component of cholesterol that is associated with increased risk of heart disease. Nicotinic acid may be prescribed in addition to other cholesterol-reducing medications to further reduce triglyceride levels and increase HDL levels.

According to the National Institutes of Health, nicotinic acid may reduce LDL-cholesterol levels by 10 to 20 percent and triglycerides by 20 to 50 percent. In addition, nicotinic acid may raise HDL-cholesterol by 15 to 35 percent.

While nicotinic acid is available over-the-counter, physicians often prefer to prescribe it in time-released pills. Side effects of large doses of nicotinic acid can be intense and may include flushing, palpitations and nausea. Patients are often directed to slowly build up to the high doses of nicotinic acid needed to treat high cholesterol. Even with proper buildup, as many as 50 percent of patients find the side effects of this medication too difficult to tolerate. Because of the potentially intense side effects, patients should never begin taking large doses of niacin supplements without the supervision of a physician. Recent research has revealed an interaction with immune cells as the mechanism that causes the flushing or hot flashes. Researchers may be able to use this information to moderate nicotinic acid therapy to minimize the flushing response.

Various amounts of niacin may also be prescribed for a number of other conditions, including:

• Cancer
• Diabetes
• Prolonged diarrhea or fever
• Hartnup disease (a rare, inherited metabolic disorder)
• Persistent infection
• Stomach ulcer or intestinal problems
• Liver or pancreas disease
• Mouth or throat sores
• Hyperthyroidism (overactive thyroid)
• Chronic stress 
• Surgical removal of stomach.

Patients should not begin taking niacin for these or other conditions without consulting their physician.

Claims may be made that niacin is an effective treatment for other ailments, including acne, leprosy, motion sickness, poor circulation, mental disorders, leprosy, alcoholism and the unwanted effects of drug abuse. However, none of these claims have been scientifically proven. Recent studies suggest that the use of niacin may be helpful in reducing the risk of heart attack. Its main therapeutic use for the cardiovascular system remains to reduce blood cholesterol levels, and a reduction in blood cholesterol levels has been proven to reduce the risk of heart disease and heart-related death.

Flushing or hot flashes, particularly in the face, neck and ears, are the most common side effects. This warm sensation may occur when individuals first begin taking nicotinic acid or when the dose is increased.  To counteract this unpleasant effect, physicians may prescribe aspirin, a non-steroidal anti-inflammatory (NSAID) or an antihistamine to be taken before the niacin to reduce the risk of flushing.

Another common side effect is dizziness or lightheadedness, especially when rising from a seated position or after lying down. Getting up slowly may help reduce this side effect. This side effect usually lessens after a few weeks, as the body become more accustomed to the medication. Patients should notify their physician immediately if they experience any side effects such as:

Other potential side effects include:

• Headache
• Palpitations and/or an abnormal heartbeat (arrhythmia)
• Gas and/or indigestion
• Diarrhea
• Nausea and/or vomiting
• Dry and/or itchy skin
• Fever
• Frequent urination
• Pain in joints, side, lower back and/or stomach
• Muscle aching or cramping
• Swelling (edema) of the feet or lower legs
• Excessive thirst
• Tiredness, weakness and/or fatigue

Whenever vitamin B3 is taken in high doses (especially the time-release versions), there are concerns regarding a number of conditions that could develop, including:

• Liver inflammation
• Gout
• Peptic ulcers
• Elevated blood sugar (glucose) levels and insulin resistance

Since nicotinic acid (niacin) is a vitamin that occurs naturally in food, it does not generally cause problems with other medications. However, the amount of nicotinic acid needed to treat high cholesterol is significantly higher than what is ingested as part of a normal diet. Therefore, patients should consult their physician before taking any other medication, either prescription, over-the-counter or nutritional supplements. Vitamin E supplements, for example may block the effects of nicotinic acid and statins. Of particular concern for patients taking large doses of niacin are:

Whenever vitamin B3 is taken in high doses, there are concerns regarding liver inflammation. Because of this, patients taking high-dose nicotinic acid (niacin) may undergo regular blood testing, specifically liver enzyme tests. Patients should also be aware of any signs or symptoms of liver inflammation, including jaundice (yellowing of the eyes and/or skin).

When patients first begin taking nicotinic acid, they may feel periods of dizziness or lightheadedness, especially when rising from a seated position or after lying down. Getting up slowly may help reduce this symptom. This side effect usually lessens after a few weeks, as the body become more accustomed to the medication.

Those taking extended-relief (or time-released) capsules should be careful not to crush, break or chew the capsules. Those having difficulty swallowing a capsule may mix the contents of the capsule into some jam or jelly and then swallow without chewing. People taking time-release tablets may break the tablet only if it is scored (dented to allow for easy breaking). Tablets must not be crushed or chewed before swallowing.

Patients should carefully follow the directions for taking their medication provided by their physician and pharmacy. Those who miss a dose of this medication should take it as soon as possible, unless it is nearly time for the next dose. In that case, the missed dose should be skipped. Double doses of this medication should not be taken.

Nicotinic acid may be less effective in people who are significantly overweight. Therefore, in addition to lifestyle changes recommended to reduce blood fat levels, patients may be placed on a weight loss program. In many cases, the lifestyle changes needed to manage blood fats will be similar to those in a weight loss program (e.g., diet, exercise, stress management).

All patients taking nicotinic acid should inform their physician immediately of any side effects or concerns. Patients should not abruptly stop taking their medications without first consulting their physicians. It is also important that patients notify all physicians (including dentists) that they are taking nicotinic acid before undergoing any surgical procedure.

Most patients on medication to treat high cholesterol (hypercholesterolemia) will take it for the rest of their lives, provided no serious side effects occur. Patients should remember that medications may control high cholesterol, but they do not cure it. Even if all their symptoms are relieved, patients should continue to take their medication exactly as directed, eat a heart-healthy diet that is low in saturated fats and keep all scheduled follow-up appointments with their physician.

Niacin use during pregnancy has not been tested on humans, so it is not known for certain if nicotinic acid impairs fertility or causes harm to the fetus. However, it is recommended that women taking niacin to reduce high cholesterol discontinue the drug if they plan to – or believe they have – become pregnant. Niacin is excreted in breast milk, and is therefore not recommended for nursing mothers. Patients are encouraged to discuss their concerns with their physicians.

Preparing questions in advance can help patients have more meaningful discussions with their physicians about their condition. Patients may wish to ask their doctors the following questions related to nicotinic acid:

1. Will nicotinic acid help my condition?
2. What are the benefits of nicotinic acid over other medications?
3. What are the risks associated with this treatment?
4. What type of nicotinic acid should I take?
5. Will it interfere with any other medications or supplements I am taking?
6. What can I do to reduce the hot flashes?
7. What other side effects can I expect from nicotinic acid?
8. Will the side effects lessen with time?
9. What symptoms indicate the need for medical attention?
10. What are my alternatives if I cannot tolerate nicotinic acid?
11. How quickly will nicotinic acid improve my cholesterol levels?
12. How long will I need to take this medicine?
13. Do I have any conditions that prevent me from using nicotinic acid?
14. Will nicotinic acid help other problems like arthritis, in addition to cholesterol?