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.