UPDATE 4-US warns of muscle damage when heart drugs combined

(Adds Abbott Laboratories comment, paragraph 11)

By Lisa Richwine

WASHINGTON, Aug 8 (Reuters) - U.S. health officials warned the public on Friday about the risk of a rare type of muscle injury seen when the cholesterol drug simvastatin is combined with the anti-arrhythmia medicine amiodarone.

The Food and Drug Administration said it continued to receive reports of rhabdomyolysis, a type of muscle injury that can lead to kidney failure or death, despite a 2002 warning about combining the drugs.

Simvastatin is an ingredient in Merck & Co's (MRK.N: Quote, Profile, Research, Stock Buzz) Zocor and Abbott Laboratories Inc's (ABT.N: Quote, Profile, Research, Stock Buzz) Simcor, and is sold generically. It also is one of two components in Merck and Schering-Plough Corp's (SGP.N: Quote, Profile, Research, Stock Buzz) Vytorin.

Amiodarone is an ingredient in Wyeth's (WYE.N: Quote, Profile, Research, Stock Buzz) Cordarone and is also sold generically. Upsher-Smith sells a version under the name Pacerone. The drug is used to control a life-threatening type of abnormal heart beat.

All drugs in the statin class of medicines, which include simvastatin, Pfizer Inc's Lipitor (PFE.N: Quote, Profile, Research, Stock Buzz) and others, carry a potential risk of rhabdomyolysis.

But compared with other statins, the risk is "more pronounced" when simvastatin is given with amiodarone, the FDA said. The risk increased with simvastatin doses greater than 20 milligrams per day.

"Prescribers should be aware of the increased risk of rhabdomyolysis when simvastatin is prescribed with amiodarone, and they should avoid doses of simvastatin greater than 20 mg per day in patients taking amiodarone," the FDA said in a notice on its website.  Continued...