Quinidine
The most commonly reported
anticholinergic medication with a focus on sex-related differences was
quinidine, exploring drug induced QT interval prolongation (table
2)74–76. The findings of both Benton and
Vicente74,76 suggest that women clear quinidine at a
faster rate than men. Unexpectedly, women have a more rapid onset of ECG
changes in response to drug activity than men, which is not entirely
explained by increased quinidine clearance. These studies demonstrate
sex-differences in quinidine pharmacokinetics, however the mechanism of
this difference is not clear74–76. It is possible
hormonal influences or rapid distribution after IV infusion contribute
to the faster onset of activity in women which normalizes over time to
reach equilibrium between the sexes.