WASHINGTON U.S. regulators are investigating potential risks from Abbott Laboratories Inc's HIV drug Kaletra, GlaxoSmithKline Plc's prostate drug Avodart and other medicines.
The Food and Drug Administration said on Monday it was probing reports of liver toxicity with patients who used Kaletra to prevent HIV infection after exposure to the AIDS virus.
The agency also said it was investigating cases of male breast cancer in patients treated with Avodart as well as Merck & Co's prostate drug Proscar and baldness treatment Propecia.
The FDA releases a quarterly list of safety probes to inform the public about early investigations of potential side effects that have been reported. The list released on Monday covered issues identified between October and December 2009.
Being on the list does not mean the FDA has concluded the drug causes the specific risk, the agency said.
Abbott spokeswoman Elizabeth Hoff said the company added information to Kaletra's label last week noting that patients who took the drug to prevent HIV infection were among those who should undergo liver monitoring tests.
The label says some reported cases of liver dysfunction were serious. "However, a definitive causal relationship with Kaletra therapy has not been established," the drug label says.
Merck spokeswoman Pam Eisele said the prescribing instructions for Proscar and Propecia already mention cases of male breast cancer seen in clinical trials. Both drugs contain the same active ingredient.
"A causal relationship has not been established," she said.
Glaxo spokeswoman Sarah Alspach said the company evaluates all reported cases of breast cancer in men taking Avodart.
"Based on reports evaluated to date, there is not conclusive evidence of a causal association between Avodart and male breast cancer," she said.
The FDA posted the list here