* FDA probing Sanofi heart drug, Takeda diabetes pill
* List does not mean drug causes problem, FDA says
* Sanofi says confident in safety profile of Multaq (Adds Takeda comment)
WASHINGTON, Jan 31 (Reuters) - U.S. regulators have launched early investigations into potential risks of drugs from Sanofi-Aventis (SASY.PA), Takeda Pharmaceutical Co (4502.T) and other companies, the Food and Drug Administration said on Monday.
The FDA released its quarterly list of investigations into possible drug-safety problems. The newest list covers probes launched between July and September 2010.
Appearing on the list does not mean the FDA has concluded a drug causes the listed problem, the agency said. It also "does not mean that FDA is suggesting that healthcare providers should not prescribe the drug or that patients taking the drug should stop taking the medication."
The list was posted on the FDA's website at: bit.ly/eKC2cp.
Among the probes, the agency is reviewing a possible interaction between Sanofi's heart drug Multaq and the bloodthinner warfarin that could lead to an "increased anticoagulant effect."
Sanofi said in a statement it was "confident in the overall safety profile of Multaq," a drug used to treat abnormal heart rhythms called atrial fibrillation or atrial flutter.
"It is important to note that the FDA has not identified a causal relationship between Multaq use" and clotting time in patients taking warfarin, the company said.
Takeda's diabetes drug Actos also is under FDA review for rhabdomyolysis, a potentially serious type of muscle injury.
The company said it was aware of 67 reports of rhabdomyolysis among about 15 million Actos patients. Most were reported in Japan, "where the condition is more broadly defined" than in the United States or Europe, Takeda spokeswoman Elissa Johnsen said.
"We will work closely with the FDA to better understand the risk of rhabdomyolysis in patients treated with Actos," Johnsen said.
The FDA provided little detail on the cases. For most of the drugs, the agency said it was "continuing to evaluate this issue to determine the need for regulatory action." (Reporting by Lisa Richwine; Editing by Gerald E. McCormick, Tim Dobbyn and Sofina Mirza-Reid)