Gender effect on diuretic response to hydrochlorothiazide and furosemide

Gender has been shown to elicit differences in drug disposition and response to therapeutic agents. We measured the diuretic response to oral hydrochlorothiazide, oral and intravenous furosemide in 6 male and 6 female normal volunteers. After fasting overnight, each subject received single doses of the individual diuretics or no treatment on 4 separate days. Total urine output was collected over the next 24 hours for volume measurement and determination of sodium and potassium concentrations. There was no statistically significant difference found between male and female subjects with respect to urine flow rate, sodium, and potassium excretion rates among the treatments. However, when natriuretic response was adjusted for mg/kg of the intravenous furosemide dose received, male subjects had a higher peak sodium excretion rate than the female subjects. Results of this study reveal a gender-related difference on the natriuretic response to diuretics. Further studies are necessary to identify if this gender-related difference is caused by differences in drug metabolism, disposition, or intrinsic diuretic responsiveness at the site of action.