Effect of sex on the distribution of anticholinergic
medications
In general, males are larger than females across the lifespan, with
increased height, body mass index and waist circumference.
Comparatively, women have increased adiposity45. This
difference in body composition has failed to show much difference in
actual drug distribution and any differences attributable to this can
largely be explained by differences in total body
mass46. Distribution of drugs to the brain is
dependent upon the lipophilic nature of the blood-brain barrier which
favours passage and accumulation of lipophilic drugs. At this time, no
statistically significant difference has been found between similarly
aged women and men with respect to albumin permeability of the blood
brain barrier47 which likely can be extrapolated to at
least some medications. The brain is also protected by p-glycoprotein,
which prevents drugs from accumulating in the brain by pumping them from
brain capillary endothelial cells to the blood48.
These mechanisms have not demonstrated any sex difference.