Novartis last week issued a warning that its breast cancer drug, Femara (letrozole), has been associated with birth defects, a caution prompted by reports that the drug was being used to help a woman become pregnant.
Femara is approved for use only in postmenopausal women with breast cancer. But there is evidence some doctors have prescribed it as a fertility treatment because it suppresses estrogen and can promote ovulation.
Novartis is sending letters to fertility doctors worldwide to reiterate a warning that the drug should not be given to women who may be pregnant, a company spokeswoman said in published reports.
The FDA has not taken any action, but a spokeswoman told the Associated Press that the agency was reviewing the matter. Novartis reportedly plans to send a letter to U.S. fertility specialists in coming days.