TERAZOSIN AND DOXAZOSIN IN NORMOTENSIVE MEN WITH SYMPTOMATIC PROSTATISM - A PILOT-STUDY TO DETERMINE THE EFFECT OF DOSING REGIMEN ON EFFICACY AND SAFETY

In this pilot study, the effect of dosing schedule on the efficacy and safety of the long-acting al-adrenergic blockers, terazosin (TER) and doxazosin (DOX), was evaluated in 43 consecutive normotensive men (mean age 59.6 years) with symptoms of prostatism. Patients were randomized to one of four treatment groups: (I)TER 5 mg once in the morning (AM; n = 10), (2) TER 5 mg once in the evening (PM; n = 11), (3) DOX 4 mg once AM (n = 11), and (4) DOX 4 mg once PM (n = 11). Patients were titrated to their final dose over 3 weeks. Parameters evaluated included Boyarsky symptom score (Sx), peak uroflow (Qmax), blood pressure and occurrence of adverse events. Once stabilized, patients were seen at 3-month intervals; follow-up ranged from 4 to 17 months (mean 9.7). Clinical improvement as determined by Sr and Qmax was similar for all four treatment groups. Mean decreases in Sr at 3 months were 4.6, 5.4, 4.9, and 5.0 for TER-AM, TER-PM, DOX-AM, and DOX-PM, respectively. Mean peak uroflow increased 3.0, 3.1, 2.8, and 3.1 ml/s for TER-AM, TER-PM, DOX-AM, and DOX-PM, respectively (p < 0.05 vs. baseline). Eight patients (18%) were withdrawn from the study because of adverse events (fatigue 1, asthenia 1,headache 3, dizziness 4): 5 during the titration phase TER-AM: 2, DOX-AM: 2, TER-PM: 1) and 3 during the treatment phase (TER-AM: 2, DOX-AM: 1). In these 8 patients, the mean decreases in sitting and standing blood pressure were approximately 7/5 and 10/8 mm Hg, respectively. These data suggest that efficacy of TER and DOX was similar at the dosages employed and not affected by the dosing schedule. Adverse events in this small population were significantly decreased (p < 0.05) by dosing in the PM. These preliminary results suggest that a larger prospective study is warranted to determine (I) the comparative efficacy of TER and DOX in the treatment of symptomatic benign prostatic hyperplasia and (2) optimal timing of the medication.