Effect of dutasteride on intraprostatic androgen levels in men with benign prostatic hyperplasia or prostate cancer.

OBJECTIVES: Dutasteride exerts its beneficial effects on the prostate through suppression of intraprostatic dihydrotestosterone (DHT). The aim of this analysis was to assess the effects of the approved dose of dutasteride (0.5 mg/d), given for 2 weeks to 4 months, on the serum and intraprostatic DHT and testosterone levels in 3 randomized studies. METHODS: Intraprostatic androgen levels were measured in benign prostatic tissue collected during transurethral resection of the prostate (benign prostatic hyperplasia studies, n = 256) or radical prostatectomy (prostate cancer study, n = 51), performed after 2 weeks, or 1, 3, or 4 months of treatment with dutasteride or with placebo or surgery alone. The serum androgen levels were assessed at the same points during treatment. Data from the control groups were pooled to provide 1 comparison group. RESULTS: Dutasteride reduced the intraprostatic DHT levels by 83%, 90%, 92%, and 93% after 2 weeks and 1, 3, and 4 months of treatment, respectively, compared with placebo/surgery alone. Dutasteride reduced the serum DHT levels from baseline by 84% at 2 weeks and by approximately 90% at 1, 2, 3, and 4 months compared with a 5.2% increase in the control group. The decrease in DHT levels with dutasteride was accompanied by a reciprocal increase in the serum and intraprostatic testosterone levels. However, the intraprostatic testosterone levels in the dutasteride groups generally remained lower than the intraprostatic DHT levels in the control group. CONCLUSIONS: The results of our study have shown that dutasteride provides near-maximal suppression of both serum and intraprostatic DHT levels in men with benign prostatic hyperplasia or prostate cancer at all points assessed.

A 24-hour feasibility study of intraurethral valved catheter for bladder management in males with spinal cord injury.

This feasibility study was conducted to evaluate design features of the novel intraurethral valved catheter, Surinate (Urovalve, Inc; Newark, New Jersey). The device extends from the bladder neck to just beyond the external sphincter and contains a valve that can be activated by an external magnet for bladder emptying. Five patients were recruited from the Edward Hines Jr Department of Veterans Affairs Hospital spinal cord injury population. We conducted cystometry and cystoscopy to evaluate the lower urinary tract. Then, the device was inserted for 24 hours with careful monitoring. The catheter was removed from the first patient because he developed autonomic dysreflexia during implantation. The next four patients used the catheter overnight and tolerated it well: one with independent use and two with increased abdominal pressure. Emptying time was 208 +/- 99 s, residual was 42 +/- 33 mL, and the first-stream flow rate was 1.8 +/- 0.7 mL/s. The safety tether was used in three patients because the extraction device did not work. Results showed effective implantation and stability of the device in the urethra. However, objectives for use and extraction were not met. This feasibility study provided important information that will help guide design improvements for the intraurethral valved catheter.