The Food and Drug Administration Wednesday strengthened warnings on certain drugs used to treat epilepsy, bipolar disorder and nerve pain, discussing the possibility of rare skin disorders and recommending that patients of Asian ancestry undergo genetic testing before using the drugs.
The drug, carbamazepine, is available as a generic and is sold under the brand names Carbatrol by Shire PLC, Tegretol by Novartis AG and Equetro by Validus Pharmaceuticals Inc., a privately held firm.
The FDA said prescribing information for the drugs already carried a warning about the possibility of rare but severe — and sometimes life-threatening — skin reactions for all patients starting carbamazepine therapy.
However, the warning will be moved to a more prominent location on the drugs' labels and be placed in an existing black box warning that discusses risks for developing anemia. A black-box warning is the FDA's toughest drug warning and appears at the top of a drug's label.
The new recommendation that health care providers give patients with Asian ancestry a genetic test before starting treatment will also be added to the boxed warning section.
The FDA said studies have found a strong association between certain serious skin reactions and an inherited variant of a gene that is found almost exclusively in people of Asian ancestry.