• Statins and niacin (nicotinic acid, or vitamin B3) are medications used to treat high cholesterol. Both medications lower LDL (bad) cholesterol in the blood and triglycerides (fats), and raise HDL (good) cholesterol.
• Statins and niacin work by blocking the enzyme in the liver responsible for making cholesterol, and helping the liver remove the cholesterol already circulating in the blood.
• The difference is that statins do a better job than niacin of reducing LDL (bad) cholesterol in the blood, while niacin raises HDL (good) cholesterol more than statins.
• Examples of statins include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor, Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin calcium (Crestor), and simvastatin (Zocor).
• Common side effects of statins include:
  • Headache
  • Nausea
  • Vomiting
  • Constipation
  • Diarrhea
  • Rash
  • Weakness
  • Muscle Pain
• Side effects of niacin include:
  • Flushing
  • Itching
  • Stomach upset
• Dietary supplements containing niacin should not be used as prescription medications. Nonprescription forms of niacin are often immediate-release and have the potential for serious side effects, particularly at the higher doses required to treat high cholesterol.

Statins are used to lower cholesterol in the blood. They work by reducing the amount of cholesterol made by the liver and by helping the liver remove cholesterol circulating in the blood. Statins help lower LDL (bad) cholesterol and triglycerides (blood fats), while raising HDL (good) cholesterol. Statins can lower LDL cholesterol better than niacin can.

Niacin (nicotinic acid, or vitamin B3) is a vitamin that, when taken in high doses, can help lower LDL cholesterol and triglycerides while raising HDL cholesterol. Niacin can raise HDL levels more than statins can.

Statins

The most common side effects are:

• headache,
• nausea,
• vomiting,
• constipation,
• diarrhea,
• rash,
• weakness, and
• muscle pain.

The most serious side effects are liver failure and rhabdomyolysis (injury or death of muscle tissue). Serious liver damage caused by statins is rare. More often, statins cause abnormalities of liver tests. Abnormal tests usually return to normal even if a statin is continued, but if the abnormal test value is greater than three times the upper limit of normal, the statin usually is stopped. Liver tests should be measured before statins are started and if there is a medical concern about liver damage thereafter.

Rhabdomyolysis is a rare serious side effect which involves damage to muscles. Rhabdomyolysis often begins as muscle pain and can progress to loss of muscle cells, kidney failure, and death. It occurs more often when statins are used in combination with other drugs that themselves cause rhabdomyolysis or with drugs that prevent the elimination of statins and raise the levels of statins in the blood. Since rhabdomyolysis may be fatal, unexplained joint or muscle pain that occurs while taking statins should be brought to the attention of a health care professional for evaluation. Statins must not be used during pregnancy because of the risk of serious adverse effects to the developing fetus.

Statins have been associated with increases in HbA1c and fasting serum glucose levels that are seen in diabetes.
There are also post-marketing reports of memory loss, forgetfulness, amnesia, confusion, and memory impairment. Symptoms may start one day to years after starting treatment and resolve within a median of three weeks after stopping the statin.

Niacin

The most common side effects of niacin are:

• stomach upset,
• flushing,
• headache,
• reduced blood pressure upon standing (orthostatic hypotension),
• vomiting,
• diarrhea,
• itching and
• tingling sensations of the extremities.

Flushing may be reduced by taking 325 mg of aspirin 30 minutes before the niacin and by increasing the dose of niacin slowly. Drinking hot liquids or alcohol shortly before or after niacin is taken may increase the occurrence of flushing. Extended release formulations of niacin may cause flushing less frequently than immediate release formulations.

Rare cases of liver failure or muscle injury have occurred from the use of niacin. Blood tests to monitor for liver injury should be performed before niacin therapy begins, every 6-12 weeks for the first year, and then occasionally thereafter. Niacin should be discontinued if liver tests are greater than three times the upper limit of normal, are persistently elevated, or are accompanied by nausea, vomiting, or weakness.

Statins

Statins have some important drug interactions. The first type of interaction involves the enzymes responsible for the elimination of statins by the liver. Liver enzymes (specifically, the cytochrome P-450 liver enzymes) are responsible for eliminating all statins from the body with the exception of pravastatin and rosuvastatin. Therefore, drugs that block the action of these liver enzymes increase the levels of simvastatin, lovastatin, fluvastatin, and atorvastatin (but not pravastatin or rosuvastatin) in the blood and can lead to the development of rhabdomyolysis.

Drugs or agents that block these enzymes include:

• protease inhibitors, for example, indinavir (Crixivan), ritonavir (Norvir) used in treating AIDS)
• erythromycin (E-Mycin)
• itraconazole, (Sporanox)
• clarithromycin, (Biaxin)
• telithromycin (Ketek)
• cyclosporine (Sandimmune)
• boceprevir (Victrelis)
• telaprevir (Incivek)
• voriconazole (Vfend)
• diltiazem, (Cardizem, Dilacor, Tiazac)
• verapamil (Calan, Verelan, Verelan PM, Isoptin, Isoptin SR, Covera-HS)
• ombitasvir/paritaprevir/ritonavir and dasabuvir (Viekira Pak)
• grapefruit juice (> one quart daily)

Lovastatin and simvastatin should not be combined with the following drugs:

• erythromycin
• ketoconazole (Nizoral, Extina, Xolegel, Kuric)
• itraconazole
• clarithromycin
• telithromycin
• cyclosporine
• boceprevir
• telaprevir
• voriconazole
• danazol (Danocrine)
• protease inhibitors
• amiodarone (Cordarone)
• amlodipine (Norvasc)
• ranolazine (Ranexa)

Another important drug interaction occurs between statins and niacin and fibric acids, for example, gemfibrozil (Lopid), clofibrate (Atromid-S), and fenofibrate (Tricor). Niacin and the fibric acid drugs (lipid-lowering agents) can cause rhabdomyolysis or liver failure when used alone, and combining them with statins increases the likelihood of rhabdomyolysis or liver failure. Gemfibrozil should not be combined with statins. Other fibric acids and niacin are used, with caution, in combination with statins.

Cholestyramine (Questran) as well as colestipol (Colestid) bind statins in the intestine and reduce their absorption into the body. To prevent this binding within the intestine, statins should be taken one hour before or four hours after cholestyramine or colestipol.

Statins increase the effect of warfarin (Coumadin). Patients taking statins and warfarin should have their blood clotting ability monitored carefully.

Statins should not be combined with red yeast rice because red yeast rice contains a chemical that is similar to statins. Combining red yeast rice with statins can lead to serious side effects such as muscle breakdown (myopathy).

Niacin

Use of niacin with drugs that cause liver or muscle injury, for example, lovastatin (Mevacor) or simvastatin (Zocor) may increase the occurrence of liver or muscle injury.

Niacin may increase blood glucose levels in individuals with diabetes. Therefore, medications for controlling blood glucose may need to be adjusted when niacin is taken by those with diabetes.

Bile acid sequestrants (for example, cholestyramine [Questran]) bind and prevent absorption of niacin. Administration of bile acid sequestrants and niacin should be separated by 4-6 hours.