According to the prescribing information, the patients, who are designated as poor metabolizers, represent nearly 2% of whites, 4% of blacks, and 14% of Chinese. The percentage of poor metabolizers is estimated to be approximately 3% of the population, based on published studies.
The US FDA added a boxed warning to the anti-blood clotting drug Plavix (clopidogrel), alerting patients and health care professionals that the drug can be less effective in people who cannot metabolize the drug to convert it to its active form.
Mary Ross Southworth, a clinical analyst in the division of cardiovascular and renal products in the FDA’s center for drug evaluation and research, said: “We want to highlight this warning to make sure health care professionals use the best information possible to treat their patients.”