There are a number of side effects that could occur as a result of taking cholesterol drugs. Muscle aches can occur and must be immediately reported to a physician. These medicines can produce abnormal liver function in about 2 percent of the population, which can be diagnosed by periodic blood tests of liver enzymes. This liver dysfunction can rarely lead to liver failure. Patients with moderate or severe liver disease are generally advised not to take statins.

A rare but potentially fatal side effect of statins and certain fibrates is rhabdomyolysis, a severe muscle reaction in which muscle cells break down, releasing their contents into the bloodstream. Physicians can monitor patients for this complication by checking muscle enzyme levels (e.g., creatine phosphokinase, CPK) in the blood.

Rhabdomyolysis most often affects the muscles in the back or lower calves. Some patients report no symptoms. In rare cases rhabdomyolysis can lead to kidney failure or other organ failure and death. Patients should report any of the following symptoms of rhabdomyolysis to their physician immediately:

• Muscle cramps
• Pain
• Swelling (edema)
• Weakness
• Stiffness
• Tenderness
• Fever
• Dark urine
• Nausea or vomiting
• Malaise (a general feeling of illness or discomfort)

Risk of this severe complication appears to be higher in elderly patients, those taking high doses of statin and those taking statins in conjunction with a fibrate. In 2001, one statin, cerivastatin (Baycol), was voluntarily withdrawn from the market by its manufacturer because of reports that fatal cases of rhabdomyolysis had been significantly more common with cerivastatin than with other approved statin drugs. Statins carry a very low risk of side effects to the nervous system. Tingling, numbness and burning pain are some of the manifestations of peripheral neuropathy. Patients on any cholesterol-lowering drugs should also notify their physician if they experience any side effects such as:

• Allergic reaction (new onset of wheezing, respiratory congestion, itching or skin rashes)
  
  
• Abdominal pain, bloating, constipation, nausea, vomiting, heartburn or other gastrointestinal distress
  
  
• Headache
  
  
• Dizziness, lightheadedness or faintness
  
  
• Flushing of the face or neck
  
  
• Blurred vision
  
  
• Drowsiness, weakness or fatigue
  
  
• Fast or irregular heartbeat  
  
  
• Jaundice (yellowing of the skin and the whites of the eyes)
  
  
• Decreased sexual interest or sexual dysfunction
  
  
• Hair loss