A randomized double-blind study assessing 4 versus 8 mg. doxazosin for benign prostatic hyperplasia

Purpose: We compare the efficacy of 4 versus 8 mg. doxazosin for benign pro static hyperplasia. Materials and Methods: A total of 82 patients with benign prostatic hyperpl asia successfully treated with 4 mg. doxazosin were randomized in a double- blind fashion to take 4 or 8 mg. Patients were evaluated with American Urol ogical Association (AUA) symptom score, Boyarsky score, uroflowmetry and si de effect profile before, and 1 and 3 months following randomization. Results: Of the patients 42 and 40 were randomized to receive 4 and 8 mg. d oxazosin, respectively. Both groups were similar with respect to patient ag e, baseline Boyarsky and AUA symptom scores, and baseline maximum urinary f low rate. At 3 months mean improvement from baseline plus or minus standard deviation in Boyarsky score was 0.6 +/- 6.5 and 4.9 +/- 6.6 in the 4 and 8 mg. groups (p <0.05), respectively, mean improvement in AUA symptom score was 1.6 +/- 5.3 and 5.3 +/- 8.0 (p <0.05), and mean maximum flow rate diffe rence was -0.6 +/- 6.4 and + 1.4 + 7.9 (p >0.05). Of the patients 7 and 8 i n the 4 and 8 mg. groups dropped out of the study, and there were no statis tical differences in side effects between dosages. Conclusions: PI dose of 8 mg. doxazosin was more efficacious than 4 mg. and the side effects associated with both dosages appeared to be similar. The 8 mg. dose should be tried in patients who have not achieved an adequate th erapeutic response to 4 mg. and are tolerating the medication. Consideratio n should be given to increasing the dosage to 8 mg. in patients who are cli nically improved at lower dosages.