Rapid efficacy of the highly selective α(1A)-adrenoceptor antagonist silodosin in men with signs and symptoms of benign prostatic hyperplasia: pooled results of 2 phase 3 studies.

PURPOSE: We evaluated the efficacy and safety of silodosin for treatment of benign prostatic hyperplasia symptoms in 2 randomized, placebo controlled, phase 3 studies. MATERIALS AND METHODS: Men 50 years or older with an International Prostate Symptom Score of 13 or greater and peak urinary flow rate of 4 to 15 ml per second received placebo or 8 mg silodosin daily with breakfast for 12 weeks. The primary end point was International Prostate Symptom Score change from baseline to last observation. Change in peak urinary flow rate was a secondary end point. Differences in treatment efficacy were assessed by ANCOVA. RESULTS: Of 923 patients (mean age 65 years) 466 received silodosin and 457 placebo. After 0.5 week (range 3 to 4 days) of treatment patients receiving silodosin vs placebo achieved significant improvement in total International Prostate Symptom Score (difference -1.9, p <0.0001) and irritative (-0.5, p = 0.0002) and obstructive (-1.4, p <0.0001) subscores. The mean ± SD change from baseline in total International Prostate Symptom Score was -4.2 ± 5.3 for silodosin vs -2.3 ± 4.4 for placebo. Differences (silodosin vs placebo) in International Prostate Symptom Score and subscores increased by week 12 (p <0.0001). Mean change from baseline in peak urinary flow rate (ml per second) 2 to 6 hours after initial dose was greater (p <0.0001) with silodosin (2.8 ± 3.4) than placebo (1.5 ± 3.8). Differences remained significant (p <0.001) through week 12. The most common treatment emergent adverse event was (mostly mild) retrograde ejaculation (silodosin 28.1% of patients, placebo 0.9%). Few patients receiving silodosin (2.8%) discontinued because of retrograde ejaculation. Proportions of patients with treatment emergent orthostatic hypotension were similar for silodosin (2.6%) and placebo (1.5%). CONCLUSIONS: Treatment with silodosin produced rapid improvement in urinary symptoms that was sustained for 12 weeks. Silodosin was well tolerated with a low incidence of orthostatic hypotension.

Efficacy and safety of oxybutynin chloride topical gel for women with overactive bladder syndrome.

OBJECTIVE: This subgroup analysis of a phase-3 study evaluated the efficacy and safety of oxybutynin chloride topical gel (OTG) in women with overactive bladder syndrome (OAB). STUDY DESIGN: Women (n = 704) with urgency-predominant urinary incontinence received OTG or placebo for 12 weeks. The primary endpoint was change from baseline to last observation in number of daily incontinence episodes. Treatments were compared with the use of analysis of covariance. RESULTS: OTG significantly reduced the number (mean ± standard deviation) of daily incontinence episodes (OTG, -3.0 ± 2.8 episodes; placebo, -2.5 ± 3.0 episodes; P < .0001), reduced urinary frequency (P = .0013), increased voided volume (P = .0006), and improved select health-related quality-of-life domains (P ≤ .0161) vs placebo. Dry mouth was the only drug-related adverse event significantly more common with OTG (7.4%) than with placebo (2.8%; P = .0062). CONCLUSION: OTG was well tolerated and provided significant improvement in urinary symptoms and health-related quality of life in women with OAB.

Silodosin for men with chronic prostatitis/chronic pelvic pain syndrome: results of a phase II multicenter, double-blind, placebo controlled study.

PURPOSE: We evaluated the efficacy and safety of 2 doses of silodosin vs placebo in men with moderate to severe abacterial chronic prostatitis/chronic pelvic pain syndrome who had not been treated previously with α-blockers for chronic prostatitis/chronic pelvic pain syndrome. MATERIALS AND METHODS: In this multicenter, randomized, double-blind, phase II study, men 18 years old or older with chronic prostatitis/chronic pelvic pain syndrome, a total National Institutes of Health Chronic Prostatitis Symptom Index score of 15 or greater and a National Institutes of Health Chronic Prostatitis Symptom Index pain score of 8 or greater received 4 or 8 mg silodosin, or placebo once daily for 12 weeks. The primary efficacy end point was change from baseline to week 12 in National Institutes of Health Chronic Prostatitis Symptom Index total score. RESULTS: Of 151 patients (mean age 48 years) 52 received 4 mg silodosin, 45 received 8 mg silodosin and 54 received placebo. Silodosin 4 mg was associated with a significant decrease in total National Institutes of Health Chronic Prostatitis Symptom Index score (mean ± SD change -12.1 ± 9.3) vs placebo (-8.5 ± 7.2, p = 0.0224), including a decrease in urinary symptom (-2.2 ± 2.7, placebo -1.3 ± 3.0, p = 0.0102) and quality of life (-4.1 ± 3.1, placebo -2.7 ± 2.5, p = 0.0099) subscores. The 4 mg dose of silodosin also significantly increased Medical Outcomes Study Short Form 12 physical component scores (4.2 ± 8.1, placebo 1.7 ± 9.0, p = 0.0492). During global response assessment 56% of patients receiving 4 mg silodosin vs 29% receiving placebo reported moderate or marked improvement (p = 0.0069). Increasing the dose of silodosin to 8 mg resulted in no incremental treatment effects. CONCLUSIONS: Silodosin 4 mg relieved symptoms and improved quality of life in men with chronic prostatitis/chronic pelvic pain syndrome but its efficacy requires confirmation in additional studies.

Rapid efficacy of the highly selective alpha1A-adrenoceptor antagonist silodosin in men with signs and symptoms of benign prostatic hyperplasia: pooled results of 2 phase 3 studies.

PURPOSE: We evaluated the efficacy and safety of silodosin for treatment of benign prostatic hyperplasia symptoms in 2 randomized, placebo controlled, phase 3 studies. MATERIALS AND METHODS: Men 50 years or older with an International Prostate Symptom Score of 13 or greater and peak urinary flow rate of 4 to 15 ml per second received placebo or 8 mg silodosin daily with breakfast for 12 weeks. The primary end point was International Prostate Symptom Score change from baseline to last observation. Change in peak urinary flow rate was a secondary end point. Differences in treatment efficacy were assessed by ANCOVA. RESULTS: Of 923 patients (mean age 65 years) 466 received silodosin and 457 placebo. After 0.5 week (range 3 to 4 days) of treatment patients receiving silodosin vs placebo achieved significant improvement in total International Prostate Symptom Score (difference -1.9, p <0.0001) and irritative (-0.5, p = 0.0002) and obstructive (-1.4, p <0.0001) subscores. The mean +/- SD change from baseline in total International Prostate Symptom Score was -4.2 +/- 5.3 for silodosin vs -2.3 +/- 4.4 for placebo. Differences (silodosin vs placebo) in International Prostate Symptom Score and subscores increased by week 12 (p <0.0001). Mean change from baseline in peak urinary flow rate (ml per second) 2 to 6 hours after initial dose was greater (p <0.0001) with silodosin (2.8 +/- 3.4) than placebo (1.5 +/- 3.8). Differences remained significant (p <0.001) through week 12. The most common treatment emergent adverse event was (mostly mild) retrograde ejaculation (silodosin 28.1% of patients, placebo 0.9%). Few patients receiving silodosin (2.8%) discontinued because of retrograde ejaculation. Proportions of patients with treatment emergent orthostatic hypotension were similar for silodosin (2.6%) and placebo (1.5%). CONCLUSIONS: Treatment with silodosin produced rapid improvement in urinary symptoms that was sustained for 12 weeks. Silodosin was well tolerated with a low incidence of orthostatic hypotension.

Efficacy and safety of oxybutynin chloride topical gel for overactive bladder: a randomized, double-blind, placebo controlled, multicenter study.

PURPOSE: We assessed the efficacy and safety of oxybutynin chloride topical gel vs placebo in adults with overactive bladder. MATERIALS AND METHODS: Men and women 18 years or older with urge predominant urinary incontinence were enrolled in randomized, parallel group, double-blind, placebo controlled Study OG05009 done at 76 clinics in the United States. Eligible patients were assigned to receive 1 gm oxybutynin chloride topical gel (10% weight per weight ethanol based formulation of oxybutynin) or matching placebo once daily for 12 weeks. Efficacy was assessed using data from 3-day urinary diaries and the primary outcome was the change from baseline in the number of urge incontinence episodes. Safety was monitored through adverse event reporting. Efficacy results in the oxybutynin chloride topical gel and placebo groups were compared by ANCOVA with last observations carried forward. RESULTS: A total of 789 randomized patients, including 704 women (89.2%), with a mean age of 59 years were assigned to treatment with oxybutynin chloride topical gel (389) or placebo (400). The mean number of urge incontinence episodes decreased significantly more in patients treated with oxybutynin chloride topical gel than in those given placebo (-3.0 vs -2.5 per day, p <0.0001). Mean urinary frequency decreased (-2.7 per day, p = 0.0017) and voided volume increased (21.0 ml, p = 0.0018) significantly more in the oxybutynin chloride group than in the placebo group (-2.0 per day and 3.8 ml, respectively). Treatment related dry mouth was more frequent in the oxybutynin chloride group than in the placebo group (27 of 389 patients or 6.9% vs 11 of 400 or 2.8%). Application site reactions were infrequently observed in the oxybutynin chloride and placebo groups (21 of 389 patients or 5.4% and 4 of 400 or 1.0%, respectively). No serious treatment related adverse events occurred. CONCLUSIONS: Oxybutynin chloride topical gel was efficacious in improving overactive bladder symptoms and was well tolerated in adult patients.

Efficacy and safety of transdermal and oral oxybutynin in children with neurogenic detrusor overactivity.

PURPOSE: We evaluated the efficacy and safety of transdermal and oral oxybutynin in children with neurogenic detrusor overactivity. MATERIALS AND METHODS: Children with neurogenic detrusor overactivity 6 to 15 years old and previously receiving oxybutynin were assigned randomly at a 3:1 ratio to treatment with transdermal or oral oxybutynin. Initial dosages (transdermal 1.3, 2.9 or 3.9 mg daily; oral 5, 10 or 15 mg daily), based on pre-study dosages, were adjusted after 2 weeks and then maintained for 12 weeks. The primary efficacy end point was change from baseline to last observation in average urine volume collected by clean intermittent catheterization. RESULTS: A total of 57 patients were randomized to receive transdermal (41) or oral (16) oxybutynin. Safety data were available for 55 patients and efficacy data were available for 52. Mean +/- SD urine volume increased from 95 +/- 64 ml to 125 +/- 74 ml (p <0.001) with transdermal oxybutynin and from 114 +/- 75 ml to 166 +/- 92 ml (p = 0.002) with oral oxybutynin. Transdermal oxybutynin resulted in significant improvement in all measured urodynamic parameters. Similar trends and a significant increase in maximal cystometric bladder capacity were observed in the smaller oral oxybutynin group. There were 12 treatment related adverse events noted with transdermal oxybutynin (mild skin reaction) and 1 with oral oxybutynin (vasodilatation). The ratio of N-desethyloxybutynin-to-oxybutynin plasma concentrations was substantially lower with transdermal (1.4) than with oral (6.7) oxybutynin. CONCLUSIONS: Transdermal oxybutynin was a well tolerated and effective alternative to oral oxybutynin in treating neurogenic detrusor overactivity in children who previously tolerated oxybutynin.

Effect of baseline symptom severity on continence improvement mediated by oxybutynin chloride topical gel.

BACKGROUND: In a recent placebo-controlled Phase III study, oxybutynin chloride topical gel (OTG) significantly improved urinary continence in patients with overactive bladder. In this post hoc analysis, the effect of incontinence severity on OTG-mediated improvement in continence was evaluated. METHODS: Change from baseline in the number of incontinence episodes was evaluated in patients with two to three incontinence episodes/day (moderate incontinence) and those with more than three incontinence episodes/day (severe incontinence). RESULTS: In patients with moderate (n = 171) and severe (n = 556) incontinence, reduction in incontinence episodes (mean ± standard deviation) was greater (P < 0.01) with OTG (moderate, -1.7 ± 1.4; severe, -3.6 ± 3.0) than with placebo (moderate, -1.2 ± 1.3; severe, -3.1 ± 3.4). Continence achievement rate with OTG was 48.2% (placebo, 24.4%) among patients with moderate incontinence and 17.8% (placebo, 12.1%) among those with severe incontinence. CONCLUSION: Absolute placebo-adjusted reduction in incontinence episodes with OTG was not affected by baseline incontinence severity. Continence achievement was more likely if symptoms were less severe.

Pharmacokinetics of oxybutynin chloride topical gel: effects of application site, baths, sunscreen and person-to-person transference.

BACKGROUND: Oxybutynin chloride topical gel (OTG; Gelnique®) is an approved formulation for the transdermal administration of oxybutynin, an established antimuscarinic therapy for overactive bladder (OAB). Transdermal administration of oxybutynin minimizes plasma concentrations of the active metabolite N-desethyloxybutynin (N-DEO), which can have anticholinergic adverse effects. OBJECTIVES: In four phase I studies, we separately assessed the effects of OTG application site selection on oxybutynin bioavailability (site-to-site study); the effects of post-application showering on oxybutynin steady-state pharmacokinetics (showering study); the effects of sunscreen application on oxybutynin absorption (sunscreen study); and the person-to-person transfer of oxybutynin through skin-to-skin contact at the application site (transference study). METHODS: All four studies were open-label, randomized, phase I studies. The site-to-site and showering studies involved repeated administration of OTG to establish steady-state plasma concentrations of oxybutynin and N-DEO; the other two studies involved single doses. Clinical visits were required for pharmacokinetic sampling, supervision of OTG self-application on pharmacokinetic sampling days, showering, sunscreen application and transference experiments. The study included healthy subjects aged 18-45 years. Subjects with conditions requiring medical therapy or interfering with the application of OTG or the interpretation of pharmacokinetic results were excluded. Participants applied OTG (1 g containing oxybutynin chloride 10%, 1.14 mL/dose) once daily to the abdomen, upper arm/shoulder or thigh. Showering occurred 1-6 hours after dosing. Sunscreen was applied 30 minutes before or after OTG application. Abdomen-to-abdomen contact with movement for 15 minutes between treated and untreated participants was conducted 1 hour after dosing. Time points of serial blood sampling for pharmacokinetic analyses varied among studies. Plasma concentrations of oxybutynin and N-DEO (except transference study) were measured. Bioequivalence was tested with ANOVA models for log(e)-transformed plasma exposure (area under the plasma concentration-time curve [AUC]) and maximum plasma concentration (C(max)) to generate 90% confidence intervals (CIs). RESULTS: Oxybutynin and N-DEO exposures (AUCs) from time zero to 24 hours (AUC(24)) were similar for the three application sites, with N-DEO/oxybutynin mean AUC(24) ratios of approximately 0.9. The 90% CIs for thigh-to-abdomen ratios of oxybutynin AUC(24) (0.93, 1.23) and C(max) (0.85, 1.16) were within the interval required for bioequivalence (0.8, 1.25); the other application site ratios for oxybutynin had boundaries slightly outside this interval. Showering 1-6 hours and sunscreen application 30 minutes before or after OTG application had minor effects on oxybutynin concentrations. After vigorous skin contact between treated and untreated participants at the application site, the mean ± SD AUC from time zero to 48 hours (AUC(48)) of oxybutynin in 12 untreated participants was 29.8 ± 24.5 ng · h/mL, approximately one-quarter of the exposures generally seen in subjects treated with a single dose of OTG. Oxybutynin AUC(48) after clothing-to-skin contact was undetectable in 12 of 14 untreated participants and very low (mean ± SD 0.4 ± 0.8 ng · h/mL) in two untreated female participants. CONCLUSION: The bioavailability of oxybutynin and its pharmacokinetic profile are not greatly affected by application site selection, post-application showering or sunscreen use shortly before or after dosing with OTG. Oxybutynin transference to untreated persons is essentially prevented by avoiding direct skin-to-skin contact with the application site.

Lack of pharmacodynamic interaction of silodosin, a highly selective alpha1a-adrenoceptor antagonist, with the phosphodiesterase-5 inhibitors sildenafil and tadalafil in healthy men.

OBJECTIVES: To evaluate the orthostatic effects and safety of coadministration of silodosin with the phosphodiesterase-5 inhibitors sildenafil and tadalafil. METHODS: In this placebo-controlled, open-label crossover study, 22 healthy men aged 45-78 years received 8 mg silodosin for 21 days. On days 7, 14, and 21, subjects also received a single dose of sildenafil 100 mg, tadalafil 20 mg, or placebo in random sequence. Orthostatic tests were performed before (baseline) and 1-12 hours after single-dose treatment. A positive orthostatic test was defined as decrease in systolic blood pressure (SBP) >30 mm Hg, decrease in diastolic blood pressure (DBP) >20 mm Hg, increase in heart rate (HR) >20 bpm, or presence of orthostatic symptoms. Treatment effects were compared by analysis of covariance. RESULTS: In comparison with placebo, sildenafil or tadalafil caused small but statistically significant reductions in blood pressure; however, no statistically significant orthostatic changes in SBP, DBP, or HR (P >.05) were caused. Time-matched maximum mean difference (95% confidence interval) vs placebo in 1-minute orthostatic change was -2.3 (-6.8-2.2) mm Hg for SBP, -2.2 (-5.6-1.2) mm Hg for DBP, and 1.7 (-1.5-4.9) bpm for HR. The number of postdose positive orthostatic tests was similar for all treatments (sildenafil, 57; tadalafil, 59; placebo, 53). Adverse events (in 7 subjects) were mild (26) or moderate (2). No orthostatic symptoms occurred. CONCLUSIONS: Coadministration of silodosin and maximum therapeutic doses of sildenafil or tadalafil in healthy men caused no clinically important orthostatic changes in blood pressure or HR and no orthostatic symptoms.

Effect of silodosin on specific urinary symptoms associated with benign prostatic hyperplasia: analysis of international prostate symptom scores in 2 phase III clinical studies.

PURPOSE: Pooled results from 2 randomized, placebo-controlled, US phase III studies (NCT00224107, NCT00224120) showed that silodosin, a uroselective α-blocker, significantly improved International Prostate Symptom Scores (IPSS) in men with symptomatic benign prostatic hyperplasia (BPH). This analysis evaluated the effect of silodosin on each symptom assessed by IPSS questionnaire. MATERIALS AND METHODS: Study participants (N = 923) were men aged ≥50 years with IPSS ≥13 and Qmax 4-15 mL/s. They received silodosin 8 mg or placebo once daily for 12 weeks. Patient responses to 7 IPSS questions were collected at weeks 0 (baseline), 0.5, 1, 2, 4, and 12 and scored on a 6-point scale. Efficacy of silodosin versus placebo was assessed by analysis of covariance. RESULTS: For each symptom, the 2 treatment groups had similar mean baseline scores. Decrease in score from baseline (mean ± standard deviation) to last observation was significantly greater with silodosin than with placebo for all symptoms (P < 0.005); symptom improvement with silodosin (versus placebo) was greatest for weak stream (silodosin, -1.1 ± 1.4 versus placebo, -0.5 ± 1.2; P < 0.0001) and smallest for nocturia (silodosin, -0.6 ± 1.1 versus placebo, -0.4 ± 1.2; P = 0.0037). Compared with placebo, silodosin significantly improved nocturia within 1 week (silodosin, -0.5 ± 1.07 versus placebo, -0.3 ± 1.05; P = 0.009) and all other symptoms within 3 to 4 days (P < 0.01). CONCLUSIONS: Silodosin significantly improved all BPH-associated symptoms assessed by IPSS questionnaire within the first week of treatment. All improvements were maintained over the 12-week study period.

Silodosin in the treatment of the signs and symptoms of benign prostatic hyperplasia: a 9-month, open-label extension study.

OBJECTIVES: To evaluate long-term safety of the highly selective alpha(1A)-adrenoceptor antagonist silodosin in men with signs and symptoms of benign prostatic hyperplasia (BPH). METHODS: Patients enrolled in this open-label extension study had completed 1 of 2 identical double-blind, placebo-controlled 12-week studies of silodosin treatment for symptomatic BPH. For 40 weeks, patients received silodosin 8 mg once daily with breakfast. Adverse events (AEs) were recorded to evaluate safety. Change in International Prostate Symptom Score was a secondary variable. RESULTS: Of the 661 participants, 435 (65.8%) completed the study; 431 patients (65.2%) experienced 924 AEs. No serious AEs that were considered drug-related by investigators occurred. AEs reported most often (percentage of patients) were retrograde ejaculation (20.9%), diarrhea (4.1%), and nasopharyngitis (3.6%). Orthostatic hypotension and dizziness occurred in 2.6% and 2.9% of patients, respectively. The percentage of patients with treatment-emergent AEs, stratified by preceding double-blind treatment (placebo or silodosin), was higher for de novo (previous treatment with placebo, 71.5%) than for continuing silodosin treatment (58.3%). More patients receiving de novo (7.5%) vs continuing treatment (1.9%) discontinued study participation because of retrograde ejaculation. Mean International Prostate Symptom Score change (standard deviation) from baseline to week 40 (observed cases) was -4.5 (6.7) for de novo treatment (P <.0001) and -1.6 (6.0) for continuing treatment (P <.01). CONCLUSIONS: Silodosin was well tolerated by men with BPH-related symptoms and was associated with low incidences of dizziness and orthostatic hypotension. Discontinuation because of retrograde ejaculation was more common among patients receiving silodosin de novo than in those who continued silodosin treatment.