Genetic test prior to carbamazepine recommended for Asians

December 13, 2007

Asians should receive genetic test prior to initiating carbamazepine

An increased risk of serious skin reactions in Asians taking carbamazepine has prompted the FDA to include a recommendation for genetic testing prior to beginning treatment. According to the agency, the risk of life-threatening skin reactions in Caucasians is about one to six per 10,000 new users, but Asians? risk is some 10 times higher. Studies have found that there is a strong association between severe skin reactions and presence of inherited gene variant, HLA-B* 1502, found almost exclusively in people of Asian decent. Skin reaction warnings will now be included in the black box warning section of the prescribing information, along with a recommendation to healthcare providers to perform a genetic test in Asian patients prior to initiating therapy. Patients who do test positive for the variant should not receive the drug unless the benefit clearly outweighs the increased risk. Patients who have already taken carbamazepine for more than a few months without any skin reaction are unlikely to ever experience one, regardless of ancestry or genetic test results. See