Systemic Augmentation of Nitric Oxide: Is There an Immediate Effect on the Urinary Flow Rate in Healthy Men?

Comparison of the efficacy of isosorbide mononitrate and doxazosin in the treatment of lower urinary tract symptoms and benign prostatic hyperplasia: a randomized clinical trial

OBJECTIVE

We aimed to compare the efficacy of isosorbide mononitrate and doxazosin in the treatment of lower urinary tract symptoms (LUTS).

PATIENTS AND METHODS

80 patients with LUTS were included in this randomized clinical study. All patients were evaluated with uroflowmetry, post-void residual (PVR) urine, prostate volume, International Prostate Symptom Score (IPSS), serum PSA, urinalysis and culture. 40 patients were prescribed doxazosin for 4 weeks, another 40 were prescribed isosorbide mononitrate for 4 weeks. Urologic re-evaluation was done at the end of the study.

RESULTS

74 patients completed the study. The mean age of patients was 59.6 ± 0.7 years, the mean PSA value was 1.7 ± 0.1 ng/ml and the mean prostate volume was 41.9 ± 1.7 ml. Doxazosin markedly improved IPSS (from 16.2 ± 0.7 to 9.5 ± 0.5), maximum urinary flow rate (from 10.9 ± 0.7 to 12.8 ± 0.6 ml/s) and PVR urine (from 68.1 ± 9.4 to 39.0 ± 4.4 ml) (p < 0.0001, p < 0.0001, p = 0.0004, respectively). Isosorbide only improved IPSS (from 16.5 ± 0.9 to 14.6 ± 0.8) (p = 0.032).

CONCLUSIONS

Daily administration of isosorbide does not seem to be an alternative to α-blocker therapy. Controlled, randomized novel studies are required to establish that whether nitric oxide donors are an effective alternative in LUTS treatment.

Systemic Nitric Oxide Augmentation Leads to a Rapid Decrease of the Bladder Outlet Resistance in Healthy Men

OBJECTIVE

We examined the immediate effect of a systemic nitric oxide augmentation on the bladder outlet resistance in healthy men.

METHODS

Eleven healthy male volunteers with a mean age of 25.5 yr were included in the study. They were prepared for a standard urodynamic study, and a baseline pressure-flow study was obtained. The subjects were then given 20 mg isosorbide dinitrate sublingually, and after refilling their bladder a second pressure-flow study was done after 20 min. The pressure-flow studies were then compared in regard to the average flow rate, the average detrusor pressure during micturition, and the detrusor pressure at maximum flow rate.

RESULTS

One of the subjects was unable to void and had to be excluded from the study. In the remaining 10 men, the mean average flow rate increased from 16.7 ml/s before to 20.2 ml/s after the intake of the NO donor (P=0.013). Concomitantly, the average detrusor pressure during micturition decreased from a mean of 57 to 52 cm H2O (P=0.004) and the mean detrusor pressure at maximum flow rate decreased from 60 to 52 cm H2O (P=0.013).

CONCLUSIONS

Systemic NO augmentation can lower the functional bladder outlet resistance very rapidly in men. Our results support the concept that the NO-cGMP pathway may be a promising target for medical treatment of lower urinary tract symptoms.