Effect of charcoal-broiled beef on antipyrine and theophylline metabolism.

Eight healthy volunteers were sequentially fed a control diet, a charcoal-broiled beef--containing diet, and the control diet a second time. The mean plasma half-lives (t1/2) of antipyrine and theophylline were each decreased by 22% after the subjects were fed the charcoal-broiled beed--containing diet. The main plasma t1/2s for these drugs returned to control values when the subjects were fed the control diet for a second time. Considerable individuality occurred in the responsiveness of the subjects to the charcoal-broiled beef--containing diet. The decreases in antipyrine plasma t1/2s among the 8 subjects ranged from 5% to 39%, and the decreases in theophylling t1/2s ranged from 0% to 42%.