Although these drugs have been successful in managing the cardiac health of many patients, all of the statins have been associated with myopathy (any disease of the muscles with symptoms including muscle weakness, primarily in the arms and legs.) Additionally, there are factors that may increase the risk of myopathy when using statins. They include the following:

• Age greater than 80 years
  
• Being female, small body frame and frailty
  
• Having diseases that involve many body systems
  
• Immediately after having surgery
  
• Using many medications, or the combination of specific medications with statins
  

Using one or more of the below medications in conjunction with statins, are a risk factor for myopathy.

• Fibrates (cholesterol-lowing drugs)
  
• Nicotinic acid (a B-complex vitamin)
  
• cyclosporine
  
• Azole antifungals
  
• Macrolide antibiotics
  
• Erythromycin and clarithromycin
  
• HIV protease inhibitors
  
• Nefazodone (antidepressants)
  
• Verapamil (calcium channel blockers)
  
• Amiodarone (antiarrhythmic)
  
• Warfarin
  
• Digoxin
  
• Large quantities of grapefruit juice (>1 quart/day)
  
• Alcohol abuse
  

The potential for myopathy is dependent on the dose. This is of great concern because more aggressive therapy using higher statin doses have been shown to significantly reduce the occurrence of death or a major coronary event, compared with those receiving a moderate therapy protocol.

The clinical presentation of statin-associated myopathies includes pain in the legs, weakness when climbing stairs, inability to open jars, weakness in the muscles closest to the shoulder, hip, and knee joints, and severe muscle cramps. These symptoms can occur at any time after starting statin therapy. Myalgia, myositis, and rhabdomyolysis are myopathies associated with statin use. Myalgia is muscle pain, aching, weakness, or stiffness without elevated CK levels (creatine kinase levels are used to measure muscle damage.) Myositis refers to muscle symptoms with increases CK levels. Rhabdomyolysis is serious muscle damage with CK levels more than ten times the normal limit, and cause possible damage to the kidneys. In addition to myalgia, symptoms of rhabdomyolysis include fever, nausea, vomiting, and dark urine.

For patients that are only using statin drugs, the incidence of myopathy is reported as 0.1% - 0.2%. The incidence increases to 1% - 7% for patients taking multiple medications and for those with multiple risk factors that were listed above. If you are on statins, it is extremely important to communicate if you experience any of the above symptoms to your health care provider, as they can be reversed with early detection.

References

Dorland’s Illustrated Medical Dictionary, 27th Ed. W.B. Saunders Company, Philadelphia, PA, 1988.
Tomlinson, SS, Mangione KK. “Potential Adverse Effects of Statins on Muscles,” Physical Therapy. 2005;85:459-465.

www.wikipedia.org