Long-term follow-up study to evaluate the efficacy and safety of the doxazosin gastrointestinal therapeutic system in patients with benign prostatic hyperplasia with or without concomitant hypertension

Clinical Efficacy and Safety of Naftopidil Treatment for Patients with Benign Prostatic Hyperplasia and Hypertension: A Prospective, Open-Label Study

PURPOSE

To investigate the efficacy and safety of naftopidil for benign prostatic hyperplasia (BPH) patients, mainly focusing on changes in blood pressure (BP).

MATERIALS AND METHODS

Of a total of 118 patients, 90 normotensive (NT) and 28 hypertensive (HT) patients were randomly assigned to be treated with naftopidil 50 mg or 75 mg for 12 weeks, once-daily. Safety and efficacy were assessed by analyzing changes from baseline in systolic/diastolic BP and total International Prostate Symptom Score (IPSS) at 4 and 12 weeks. Adverse events (AEs), obstructive/irritative subscores, quality of life (QoL) score, maximum urinary flow rate (Qmax), and benefit, satisfaction with treatment, and willingness to continue treatment (BSW) questionnaire were also analyzed.

RESULTS

Naftopidil treatment decreased mean systolic BP by 18.7 mm Hg for the HT 50 mg group (p<0.001) and by 18.3 mm Hg for the HT 75 mg group (p<0.001) and mean diastolic BP by 17.5 mm Hg for the HT 50 mg group (p<0.001) and by 14.7 mm Hg for the HT 75 mg group (p=0.022). In the NT groups (both naftopidil 50 mg and 75 mg), naftopidil elicited no significant changes in BP from baseline values. After 12 weeks, naftopidil 50 and 75 mg groups showed significant improvements in IPSS scores (total, obstructive/irritative subscores, QoL score) and Qmax from baseline. AEs were reported in 7.8% (50 mg group) and 2.9% (75 mg group) of patients. In both the 50 mg and 75 mg groups, >86% of all patients agreed to continue their current medications.

CONCLUSION

Our results suggest that naftopidil treatment in BPH patients with hypertension allows for optimal management of BP within the normal range.

Comparison of the clinical efficacy of medical treatment of symptomatic benign prostatic hyperplasia between normal and obese patients

We aimed to investigate the difference in efficacy of medical treatment of symptomatic benign prostatic hyperplasia (BPH) between normal and obese patients with BPH; obesity was determined by either body mass index (BMI) or waist circumference (WC). In this 12-week prospective observational study, a total of 175 patients aged ≥40 years with International Prostate Symptom Scores (IPSS) ≥12 points and prostate volume ≥20 ml were prospectively enrolled. The patients were divided into two groups according to BMI or WC. Patients received the doxazosin gastrointestinal therapeutic system (GITS) at a dose of 4 mg once per day for 12 weeks. The changes from baseline in the IPSS, maximal urinary flow rate (Q(max)), post-void residual volume, quality of life (QoL) scores and adverse events (AEs) were analysed. Of the 175 enrolled patients, 132 completed the study. Sixty-seven patients had BMI >23 kg m⁻², and 43 had WC >90 cm. Obese patients represented by WC >90 cm or BMI ≥23 kg m⁻² had a significantly greater prostate volume compared with non-obese patients at baseline. Total IPSS was significantly higher in the WC >90 cm group compared to the WC ≤90 cm group. Total IPSS was positively correlated with prostate volume (P=0.031) and WC (P=0.045). All groups showed significant improvements in total IPSS and QoL at 12 weeks. However, the improvement of total IPSS was greater in the high-BMI and high-WC groups. The most frequent AE was dizziness (n=13), and it was significantly lower in the obese BPH patients. Obesity was associated with increased prostate volume and lower urinary tract symptoms. Alpha-blockers appear to be efficacious for controlling symptoms, especially in obese men.

Effects of α-blocker 'add on' treatment on blood pressure in symptomatic BPH with or without concomitant hypertension

We investigated the effects of ‘add on' treatment of α-blocker (AB) on blood pressure (BP) and the safety of ABs in men with symptomatic BPH with or without hypertension. We retrospectively reviewed 2,924 BPH outpatients who took ABs at our institution between 2005 and 2009. BPH symptom severity, prostate volume and BP were determined for 953 patients with their baseline data. BP level and International Prostate Symptom Score were measured within 2 months after AB treatment. Patients were assigned to four groups: group 1 had 272 normotensive patients on concomitant hypertensive medication; group 2 had 293 normotensive patients not on the medication; group 3 had 216 hypertensive patients on concomitant medication; and group 4 had 172 hypertensive patients not on the medication. The addition of AB lowered the mean systolic BP by 16.6 mm Hg for group 3 and by 8.6 mm Hg for group 4, and diastolic BP by 18.0 mm Hg for group 3 (P&lt;0.05). However, normotensive groups on entry, irrespective of antihypertensive medication, showed no significant BP changes from baseline after AB medication. In the hypertensive groups on entry, the doxazosin gastrointestinal therapeutic system (GITS) resulted in significant reductions in systolic BP from 142.2 to 134.9 mm Hg and in diastolic BP from 97.6 to 84.6 mm Hg. When analyzed by AB regimen, the incidence of BP-related adverse events was comparable. AB therapy for BPH can have an appropriate and beneficial effect on BP, especially in baseline hypertensive patients. Doxazosin GITS treatment resulted in optimal management of BP within the normal range, especially in pharmacologically or physiologically hypertensive patients.

Pharmacology of α1-adrenoceptor antagonists in the lower urinary tract and central nervous system

The main use of alpha(1)-adrenoceptor (AR) antagonists in urology has been to treat lower urinary tract symptoms (LUTS) in men with benign prostatic obstruction (BPO). The beneficial effects of these agents are primarily assumed to be because of relaxation of prostatic and urethral smooth muscle. The weak correlation between LUTS and prostatic enlargement, outflow obstruction, or both, however, has refocused interest on the role of extraprostatic alpha-ARs in the pathogenesis of LUTS and their treatment. The alpha(1)-ARs present in the bladder, urethra, vas deferens, peripheral ganglia, nerve terminals, and in the central nervous system could all potentially influence LUTS and, when the receptors are blocked, contribute to both the therapeutic and adverse effects of alpha(1)-AR antagonists. The relevance of alpha(1)-AR-subtype selectivity on the clinical usefulness of existing drug therapies has not been firmly established but it seems that blockade of both alpha(1A/L)- and alpha(1D)-ARs is necessary for the optimum balance between clinical efficacy and adverse effects.