Sex dependent pharmacokinetics and bioequivalence--time for a change.

Bioequivalence studies have historically been performed largely in young males and then extrapolated to be applicable to both sexes at any age. This tendency continues today, yet a number of studies have shown that drug pharmacokinetics can be significantly different in women than in men, even as regards intra-patient variability. Some of our assumptions when treating women may not be accurate if we base our decisions on information obtained from studies conducted in men. Furthermore, women can have various physiological states that can affect drug disposition, and one of the most significant is pregnancy.