Racial Differences in Drug Response

To the Editor: Dr. Zhou and colleagues have elegantly demonstrated that Chinese subjects are more sensitive to the cardiovascular effects of propranolol than white subjects (March 2 issue). 1 However, I am not persuaded that the values in their Table 2 reflect real differences of such magnitude in the pharmacokinetics of propranolol in the two groups. In computing the total systemic clearance (C T ) of propranolol from the dose (D) and the area under the concentration–time curve (AUC), Zhou et al. used the formula C T = FD/AUC, but assumed that F (bioavailability) was equal to 1.0 in both groups. . . .