Effect of sex on the renal elimination of anticholinergic
medications
Kidney function is integral to drug elimination. Glomerular filtration
is related to body mass. Males typically have a greater body weight than
females45, so generally glomerular filtration is
greater in males than females. This likely explains the majority of
sex-differences in renal drug clearance, though this has not been
observed for all drugs. Sex has been found to be a significant factor in
methotrexate clearance, with a 17% reduction in females after
standardizing doses for body weight70. Some authors
have reasoned that for narrow therapeutic index drugs the sex-related
effect on kidney function may be clinically
relevant70,71. Pharmacokinetic studies have confirmed
sex-differences in renal clearance for many drugs including the weakly
anticholinergic drug digoxin, which has slower clearance in
females72 and the moderately anticholinergic drug
amantadine, which has been shown to have significantly higher renal
clearance in men due to putative sex differences in renal tubule
secretion by organic cation transporters73.
Summary of Studies Showing Sex-Differences in
Pharmacokinetics: