Evaluation of the effect of sildenafil and/or doxazosin on Benign prostatic hyperplasia–related lower urinary tract symptoms and erectile dysfunction

PURPOSE: To verify the association between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED) and evaluate the influence of sildenafil and doxazosin either as single agents or combined on both symptoms. MATERIAL AND METHODS: A prospective randomized study including 150 patients presented with LUTS caused by BPH in association with clinically diagnosed ED, with age equal or more than 45 years from April 2010 to April 20011. They were categorized into three comparative groups each one containing 50 patients. These groups were comparable regarding pretreatment international prostate symptoms score (IPSS) and international index of erectile function (IIEF). The patients of the first group were given sildenafil 50 mg as monotherapy, those of the second group were given doxazosin 2 mg and those of the third group were given combination of both drugs for 4 months for each group. The main post-treatment parameters for assessment and comparison include assessment of patient's symptoms by repeated IPS Sand IIEF, uroflowmetry and assessment of PVR. The statistics was done by use of the Qui--square test. RESULTS: Pre-treatment parameters were assessed and compared between the three groups. After 4 months of treatment, the comparative parameters were applied to all groups and the differences were measured post-treatment regarding IPSS, erectile function score, uroflowmetry, and post-void residual (PVR) urine. Sildenafil alone caused mild improvement in IPSS, more improvement in IIEF score, and little effect on flow rate and PVR urine. Doxazosin alone caused more improvement in IPSS, flow rate and PVR urine and less improvement in IIEF score. A combination of both sildenafil and doxazosin caused more improvement in all of the comparative parameters than when each drug was given alone. CONCLUSIONS: There is a strong relationship between LUTS and ED. Doxazosin or sidenafil as a single drug could be used in treating mild or mild to moderate symptoms but more severe symptoms may usually need a combination of both drugs.