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. Niacin is also present in many multiple vitamins and nutritional supplements.

Lovastatin is in a group of drugs called HMG CoA reductase inhibitors, or "statins." Lovastatin reduces levels of "bad" cholesterol (low-density lipoprotein, or LDL) and triglycerides in the blood, while increasing levels of "good" cholesterol (high-density lipoprotein, or HDL).

The combination of lovastatin and niacin is used to lower cholesterol and triglycerides (types of fat) in the blood.

Lovastatin and niacin may also be used for other purposes not listed in this medication guide.

You should not take this medication if you are allergic to niacin (Niaspan, Niacor, and others) or lovastatin (Altoprev, Mevacor), if you are pregnant or breast-feeding, or if you have liver disease, severe bleeding, or a stomach ulcer.

Stop taking this medication and tell your doctor right away if you become pregnant.

Before taking lovastatin and niacin, tell your doctor if you have ever had liver or kidney disease, heart disease, diabetes, gout, or a thyroid disorder, if you have recently had a heart attack, or if you drink more than 2 alcoholic beverages daily.

In rare cases, lovastatin and niacin can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. Call your doctor right away if you have unexplained muscle pain, tenderness, or weakness especially if you also have fever, unusual tiredness, and dark colored urine.

There are many other drugs that can increase your risk of serious medical problems if you take them together with lovastatin and niacin. Tell your doctor about all medications you use. Keep a list of all your medicines and show it to any healthcare provider who treats you.

You should not take this medication if you are allergic to niacin (Niaspan, Niacor, and others) or lovastatin (Altoprev, Mevacor), if you are pregnant or breast-feeding, or if you have liver disease, severe bleeding, or a stomach ulcer.

If you have any of these other conditions, you may need a dose adjustment or special tests:

• history of liver or kidney disease;

• diabetes;

• gout;

• a thyroid disorder;

• heart disease, or if you have recently had a heart attack;

• if you drink more than 2 alcoholic beverages daily; or

• if you are switched to this medication from regular niacin, nicotinic acid, or nicotinamide (or vitamin supplements that contain niacin).

In rare cases, lovastatin and niacin can cause a condition that results in the breakdown of skeletal muscle tissue, leading to kidney failure. This condition may be more likely to occur in older adults and in people who have kidney disease or poorly controlled hypothyroidism (underactive thyroid).

Tell your doctor about all other medications you use. Certain other drugs can increase your risk of serious muscle problems, and it is very important that your doctor knows if you are using any of them:

• danazol (Danocrine);

• nefazodone (an antidepressant);

• gemfibrozil (Lopid), fenofibric acid (Fibricor, Trilipix), or fenofibrate (Antara, Fenoglide, Lipofen, Lofibra, Tricor, Triglide);

• antibiotics such as clarithromycin (Biaxin), erythromycin (E.E.S., EryPed, Ery-Tab, Erythrocin), or telithromycin (Ketek);

• antifungal medications such as fluconazole (Diflucan), itraconazole (Sporanox), or ketoconazole (Extina, Ketozole, Nizoral, Xolegal);

• HIV medications such as atazanavir (Reyataz), ritonavir (Norvir), lopinavir/ritonavir (Kaletra), saquinavir (Invirase), and others;

• other medicines that contain niacin (Advicor, Niaspan, Niacor, Slo-Niacin, and others); or

• drugs that weaken your immune system, such as steroids, cancer medicine, or medicines used to prevent organ transplant rejection, such as cyclosporine (Gengraf, Neoral, Sandimmune), sirolimus (Rapamune), or tacrolimus (Prograf).

FDA pregnancy category X. This medication can harm an unborn baby or cause birth defects. Do not take lovastatin and niacin if you are pregnant.Stop taking this medication and tell your doctor right away if you become pregnant. Use effective birth control to avoid pregnancy while you are taking lovastatin and niacin.

Lovastatin and niacin may pass into breast milk and could harm a nursing baby. Do not breast-feed while you are taking lovastatin and niacin.