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

Objectives. In this pilot study, the effect of dosing schedule on the efficacy and safety of the long-acting alpha,-adrenergic blocker doxazosin (DOX) was evaluated in 48 consecutive, normotensive men (mean age, 61.2 years) with symptoms of prostatism. Methods. In this titration to fixed dose study, patients were randomized into 1 of 4 treatment groups: (1) 4 mg DOX once in the AM (n = 12); (2) 4 mg DOX once in the PM (n = 12); (3) 8 mg DOX once in the AM (n = 12); and (4) 8 mg DOX once in the PM (n = 12). Parameters evaluated included Boyarsky symptom score (Sx), peak uroflow (Q(max)), blood pressure, and occurrence of side effects. Once stabilized, patients were seen at 5-month intervals; follow-up ranged from 3 to 19 months (mean, 7.7). Results. Clinical improvement as determined by Sx and Q(max) was similar for AM and PM groups with either 4 or 8 mg of DOX. Mean decreases in Sx at 3 months were 4.6, 4.2, 5.1, and 5.2 and at 6 months were 4.7, 4.7, 5.3, and 5.4 for the 4 mg AM, 4 mg PM, 8 mg AM, and 8 mg PM, respectively. Mean peak uroflow at 3 months increased 2.7, 2.9, 3.2, and 3.3 mL/s and at 6 months increased 2.6, 3.0, 3.4, and 3.5 mL/s for the 4 mg AM, 4 mg PM, 8 mg AM, and 8 mg PM, respectively (p < 0.05). Six patients (13%) were dropped from the study because of side effects (2 for fatigue, 2 for headache, 2 for dizziness): 5 during the titration phase (4 mg AM: 2; 8 mg AM: 2; 8 mg PM: 1), and 1 during the treatment phase (8 mg AM). Conclusions. These data suggest that evening dosing does not diminish efficacy yet may enhance toleration of DOX. These preliminary results suggest that a larger prospective study is warranted to determine the optimal dosing and timing of DOX in the management of symptomatic benign prostatic hyperplasia.