Diuretic resistance: reduced bioavailability and effect of oral frusemide.

Diuretic resistance: reduced bioavailability and effect of oral frusemide Some patients respond poorly to diuretics.This could be due to changes in the pharmacokinetics or the pharmacodynamics of the diuretic.We report a case in which frusemide given by mouth to an oedematous patient had little effect owing to a much reduced bioavailability.