RESUMEN
To assess whether the effect of chewing Khat leaves [Catha edulis] on the urodynamics of healthy males is altered by the selective [alpha]1-adrenergic blocking agent indoramin in a prospective randomized double- blind controlled trial. Eleven male subjects aged between 22 and 52 years [mean 38.4] attended Khat chewing sessions in Sana'a, Republic of Yemen. Each was studied on two, separate days within the same week. Subjects were excluded if they had previously undergone surgery on the lower urinary tract or were taking treatment that might affect the urinary system [such as hypolensive or broncho- dilator drugs]. Khat chewing produces a fall in average and maximum urine flow rate. This effect was inhibited by indoramin. Conclusions: The urinary side-effects of Khat chewing are probably mediated through stimulation of [alpha]1- adrenergic receptors