[Treatment of obstruction caused by prostatic hypertrophy with prazosin. 1-year follow-up]

Since Caine demonstrated the presence of alpha-adrenergic receptors in prostate tissue in 1975, an alpha-blocker capable of producing maximum relaxation of prostatic tissue with minimum side effects has been sought. Prazosin, a selective alpha-1 blocking agent, must meet these requirements. We report the results of a study undertaken in 28 patients with benign hyperplasia of the prostate demonstrated by flowmetry, clinically and by ultrasound. A significant improvement was observed in all patients except for the ultrasound measured prostate size, which remained unchanged. Undesired effects were observed in 36% of the patients. Despite the initial improvement, 89.3% had abandoned treatment at 1 year principally owing to deterioration of the clinical picture and because they were submitted to surgery (the majority) or treatment with other drugs. We can conclude from our results that prazosin is useful for short-term therapy; i.e., until the patient can be referred for surgery.