Tadalafil Alone or in Combination with Tamsulosin for the Management for LUTS/BPH and ED.

PURPOSE OF REVIEW: Aim of our systematic review is to evaluate and summarize the efficacy and safety of tadalafil alone or in combination with tamsulosin for the management of lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) and erectile dysfunction (ED). RECENT FINDINGS: Daily tadalafil, in particular 5 mg, according to retrieved studies, appears to be both safe and effective in treating LUTS/BPH and ED, compared with placebo or tamsulosin. The combination of daily tadalafil 5 mg and tamsulosin 0.4 mg allows a better improvement of LUTS compared with both the monotherapies, even if with an increased, but acceptable and tolerated, adverse events rate. After discontinuation of tamsulosin or tadalafil in patients previously treated with their combination, the improvement of LUTS retains significance compared with baseline. Tadalafil 5 mg should be considered a primary treatment option for patients with LUTS/BPH and ED. Evidence highlight an excellent tolerability, safety, and effectiveness profile, both alone or in combination with tamsulosin 0.4 mg. A better efficacy on LUTS relief has been observed for combination therapy, preserving also sexual function. The further switch to monotherapy allows to preserve LUTS relief, but tadalafil only is able to retain ED improvement. Our results support the evidence for a more and more tailored and modular LUTS treatment.

Do baseline estrogen and testosterone affect lower urinary tract symptoms (LUTS) prior to or after pharmacologic treatment with tadalafil?

Little is known about how total testosterone and estradiol-17ß influence lower urinary tract symptoms (LUTS) in men with benign prostatic hypertrophy (BPH). We analyzed data from a subset of men aged ≥18 years randomized to tadalafil 5 mg once-daily or placebo who had ≥6 month history of LUTS and an International Prostate Symptom Score (IPSS)≥13 enrolled in one of three randomized, placebo-controlled tadalafil clinical trials (N = 958). Three specific aims were addressed, as follows: (i) To characterize enrolled men by treatment randomization and testosterone level; (ii) to assess cross-sectional associations of estradiol-17ß, testosterone, and LUTS prior to treatment with tadalafil; and, (iii) to assess longitudinal associations between baseline estradiol-17ß and testosterone and improvements or worsening of LUTS during a 12-week period of tadalafil or placebo administration. LUTS were assessed by total IPSS, IPSS voiding sub-score (IPSS-V) and IPSS storage sub-score (IPSS-S) for cross-sectional analyses, and change in total IPSS (ΔIPSS), ΔIPSS-V, and ΔIPSS-S between baseline and 12-week visit for longitudinal analyses. Correlation analyses and linear regression examined associations. Baseline testosterone was not significantly associated with IPSS. In contrast, estradiol-17ß was inversely correlated with IPSS (r = -0.08; p < 0.05) and IPSS-S (r = -0.14; p < 0.05). Tadalafil treatment resulted in greater IPSS improvements in men with lower baseline estradiol-17ß versus those with higher baseline estradiol-17ß. Lower baseline estradiol-17ß was significantly associated with modestly improved ΔIPSS-V (p = 0.04) and Δtotal IPSS (p = 0.05) but not with ΔIPSS-S, following treatment which may substantiate the role of bladder dysfunction because of nerve and smooth muscle changes in the bladder in addition to benign prostatic enlargement in LUTS. Circulating baseline testosterone did not predict ΔIPSS. Men with lower baseline estradiol-17ß levels showed greater responsiveness to tadalafil 5 mg treatment than those with higher baseline estradiol-17ß levels when responsiveness was measured using total IPSS and IPSS-V.

Rural vs. urban disparities in association with lower urinary tract symptoms and benign prostatic hyperplasia in ageing men, NHANES 2001-2008.

OBJECTIVE: The objective of this study was to investigate rural/urban and socio-demographic disparities in lower urinary tract symptoms and benign prostatic hyperplasia (LUTS/BPH) in a nationally representative population of men. METHODS: Data on men age ≥40 years (N = 4,492) in the 2001-2008 National Health and Nutrition Examination Surveys were analysed. Self-report of physician-diagnosed enlarged prostate and/or BPH medication use defined recognised LUTS/BPH. Urinary symptoms without BPH diagnosis/medications defined unrecognised LUTS/BPH. Rural-Urban Commuting Area Codes assessed urbanisation. Unadjusted and multivariable associations (odds ratios (OR)) between LUTS/BPH and covariates were calculated using logistic regression. RESULTS: Recognised and unrecognised LUTS/BPH weighted-prevalence estimates were 16.5% and 9.6%. There were no significant associations between LUTS/BPH and rural/urban status. Significant predisposing factors for increased adjusted odds of recognised and unrecognised LUTS/BPH included age, hypertension (OR=1.4;1.4), analgesic use (OR=1.4;1.4) and PSA level >4 ng/mL (OR=2.3;1.9) when adjusted for rural/urban status, race, education, income, alcohol, health insurance, health care and proton pump inhibitor (PPI) use (all p ≤ 0.1). Restricting to urban men only (N = 3,371), healthcare use (≥4visits/year) and PPI's increased adjusted odds of recognised LUTS/BPH (OR=2.0;1.6); no health insurance and

Management of benign prostatic hyperplasia: role of phosphodiesterase-5 inhibitors.

Several studies have highlighted a strong association between benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED), particularly in elderly men. Many epidemiological trials, such as in vitro and in vivo studies, have reported the emerging role of metabolic syndrome, including abdominal obesity, impaired glucose metabolism, hypertriglyceridemia, low high-density lipoprotein cholesterol, and hypertension, in the development and progression of urinary and sexual symptoms. Moreover, many authors have focused their studies on the identification of all the shared pathogenetic mechanisms of LUTS/BPH and ED, including alteration of cyclic guanosine monophosphate and RhoA-ROCK pathways or vascular and neurogenic dysfunction. All these are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Therefore, several trials have recently been designed to evaluate the role of PDE5-Is alone or in combination with conventional treatment for BPH, such as α-adrenergic blockers, in men affected by LUTS/BPH, with or without ED. Different PDE5-Is are in clinical use worldwide and currently six of them are licensed for the oral treatment of ED. All these compounds differ in pharmacokinetic factors, with influence on drug action, and subsequently in the overall safety and efficacy profile.

PDE5-Is for the Treatment of Concomitant ED and LUTS/BPH.

Epidemiologic data in adult men exhibit a strong relationship between erectile dysfunction (ED) and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH), indicating that men affected by ED should also be investigated for LUTS/BPH and those presenting with storage or voiding LUTS should be investigated for co-morbid ED. Common pathophysiolgical mechanisms underlying both LUTS/BPH and ED, including alteration of NO/cGMP or RhoA/Rho-kinase signaling and/or vascular or neurogenic dysfunction, are potential targets for proposed phosphodiesterase type 5 inhibitors (PDE5-Is). Several randomized controlled trials and only a few reviews including all commercially available PDE5-Is demonstrated the safety and efficacy of these drugs in the improvement of erectile function and urinary symptoms, in patients affected either by ED, LUTS, or both conditions.

Outcomes of lateral retroperitoneal reservoir placement of three-piece penile prosthesis in patients following radical prostatectomy.

While placement of a three-piece inflatable penile prosthesis (IPP) with a midline reservoir can be performed with favorable outcomes after radical prostatectomy (RP), postoperative fascial scarring can introduce surgical complexity, increase intra-operative complications and/or potential obstacles for future inguinal and/or perineal surgeries. We describe the implantation of the IPP with lateral reservoir placement through a separate incision to avoid surgical complications. We obtained clinical characteristics of all patients (1998-2009) who underwent RP before IPP placement with lateral reservoir placement (cases). For comparison, patients who underwent IPP placement with midline reservoir placement were also identified (controls). Thirty-one patients with a history of RP underwent IPP placement using the lateral placement technique without intra-operative or post-operative complications. There were no significant differences in the intra-operative complication rate among 31 control patients. However, at a median follow-up of >2 years, there was a significantly higher rate of post-operative complications in controls, likely reflecting the increased co-morbidities in this group. The results of this study suggest that three-piece IPP with lateral retroperitoneal reservoir implantation is associated with comparable long-term outcomes and can be performed safely in patients who have previously undergone RP.

PDE5 inhibitors for LUTS.

To review the current literature regarding the relationship between lower urinary tract symptoms (LUTS) and erectile dysfunction (ED), and the role of phosphodiesterase-5 (PDE5) inhibitors for the treatment of LUTS. Review of recently published (1990-2009) data regarding epidemiologic and pathophysiologic mechanisms are involved in LUTS-ED, focusing on PDE5 inhibitors particularly evidenced from level 1 clinical trials. Search terms included phosphodiesterase inhibitors, nitric oxide, autonomic hyperactivity, Rho-kinase, atherosclerosis, LUTS, benign prostatic hypertrophy, and ED. Results of several epidemiologic studies show a possible causal relationship between LUTS and ED. Four possible mechanisms have been proposed to explain this association. Multiple large clinical trials have shown a benefit in LUTS after PDE5-inhibitors treatment. PDE5 inhibitors show promise as a future treatment for LUTS, either in conjunction with existing therapies or as a primary treatment.

The role of combination medical therapy in benign prostatic hyperplasia.

To review key trials of monotherapy and combination therapy of alpha(1)-adrenergic receptor antagonists (alpha(1)-ARAs), 5alpha-reductase inhibitors (5alphaRIs) and anti-muscarinic agents in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). To assess the safety and efficacy of combination therapies for LUTS associated with BPH, a search of the MEDLINE and Cochrane databases (1976-2008) was conducted for relevant trials and reviews using the terms benign prostatic hyperplasia, lower urinary tract symptoms, alpha(1)-adrenergic receptor antagonists, 5alpha-reductase inhibitors, anti-muscarinics, anticholinergics, combination therapy, alfuzosin, doxazosin, tamsulosin, terazosin, dutasteride, finasteride, tolterodine, flavoxate, propiverine, oxybutynin, erectile dysfunction, sildenafil, vardenafil and tadalafil. Data from the Medical Therapy of Prostatic Symptoms (MTOPS) study indicated a role for long-term use of alpha(1)-ARAs and 5alphaRIs in combination. In the MTOPS study, combination therapy with the alpha(1)-ARA doxazosin and the 5alphaRI finasteride was significantly more effective than either component alone in reducing symptoms (P=0.006 vs doxazosin monotherapy; P<0.001 vs finasteride monotherapy) and in lowering the rate of clinical progression (P<0.001 vs either monotherapy). These findings were confirmed by the 2-year preliminary results of the Combination of Avodart and Tamsulosin study. In this study, combination therapy of the alpha(1)-ARA tamsulosin and the 5alphaRI dutasteride resulted in a significantly greater decrease in International Prostate Symptom Score (IPSS) when compared with either monotherapy. Several recent trials have studied the efficacy of combining alpha(1)-ARAs and anti-muscarinic agents in the treatment of BPH. These studies have found this combination to result in statistically significant benefits in quality of life scores, patient satisfaction, urinary frequency, storage symptoms and IPSS scores. Studies have not shown an increased risk of urinary retention associated with the use of anti-muscarinics in a highly select cohort of men with BPH. The available data suggest that combination therapy can be beneficial in the treatment of BPH and associated LUTS. The greatest efficacy for the alpha(1)-ARA and 5alphaRI combination was shown in patients with larger prostate size and more severe symptoms. The combination of alpha(1)-ARAs and 5alphaRIs appears to prevent disease progression in these patients. The combination of alpha(1)-ARAs with anti-muscarinic agents is useful for relieving symptoms of bladder outlet obstruction and detrusor overactivity. Theoretic concerns regarding the risk of acute urinary retention have been refuted in several recent clinical trials; however, it must be noted that the patients in these trials were a highly select cohort of men. Men with overactive bladder and BPH who are not receiving adequate alleviation of symptoms from the first-line alpha(1)-ARAs may benefit from the addition of an anti-muscarinic agent.

Sildenafil citrate improves erectile function: a randomised double-blind trial with open-label extension.

AIMS: To evaluate once-daily 100-mg sildenafil for the treatment of erectile dysfunction (ED) in men with ED and lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). METHODS: This was a 12-week, randomised, double-blind, placebo-controlled (DBPC) trial, with an 8-week open-label (OL) extension, in men > or = 45 years of age who scored < or = 25 on the erectile function (EF) domain of the International Index of Erectile Function (IIEF) and > or = 12 on the International Prostate Symptom Score. RESULTS: At DBPC end of treatment (EOT), the sildenafil group (n = 189, vs. placebo, n = 180) had improved EF (IIEF), improved emotional well-being [Self-Esteem And Relationship questionnaire (SEAR)], and greater treatment satisfaction (Erectile Dysfunction Inventory of Treatment Satisfaction) (p < 0.0001). At OL EOT, IIEF and SEAR scores improved slightly in the group previously randomised to sildenafil (n = 168), but much more in the group previously randomised to placebo (N = 155), such that total improvement over the 20-week trial was comparable between the groups. Erections at baseline were hard enough for penetration on approximately half of occasions and lasted long enough for successful intercourse on less than one quarter of occasions, increasing at sildenafil DBPC and OL EOT to approximately 90% (penetration) and 80% (intercourse success) vs. 61% (penetration) and 39% (intercourse success) for DBPC placebo. At sildenafil DBPC and OL EOT, > or = 90% of men were taking sildenafil 100 mg. Sildenafil was generally well tolerated. CONCLUSIONS: In this trial of men with ED and BPH-associated LUTS, sildenafil treatment for ED was efficacious, effective and generally well tolerated.

Sonic hedgehog, the penis and erectile dysfunction: a review of sonic hedgehog signaling in the penis.

The sinusoid anatomy of the penis is complex and requires complicated interaction between smooth muscle and endothelium in order to maintain homeostasis in the adult. The morphogen, Sonic hedgehog (Shh), is a crucial regulator of these processes, along with its down stream targets patched (Ptc), Hox, bone morphogenetic proteins (BMP's), vascular endothelial growth factor (VEGF) and nitric oxide synthase (NOS). Shh is critical for patterning and establishing tissue identity of the penis during embryonic development, is a crucial regulator of penile postnatal differentiation of the sinusoid morphology of the corpora cavernosa, and plays a fundamental role in maintaining sinusoidal structures pertinent to erectile function in the adult rat. Shh and its targets are active in human penes, and decreased in human diabetic penes in parallel with observations in the rat, thus lending clinical significance to the role of abnormal Shh signaling in erectile dysfunction (ED). Application of exogenous Shh protein to rat corpora cavernosa, induces VEGF and NOS proteins, suggesting a potential mechanism through which decreased Shh protein can cause ED. The studies outlined in this review provide in depth analysis of the Shh pathway and signal transduction, its role in penile development, how Shh signaling is altered in a rat model of ED and neuropathy, how abnormal Shh signaling can cause ED, and the clinical significance of the Shh pathway to human ED. These studies will provide valuable insight, at the molecular level, into understanding the mechanisms that under lie ED and lead to new treatment strategies for diabetic impotence.

Smoking and erectile dysfunction: evidence based analysis.

PURPOSE: We examined available evidence concerning the role of smoking in the development of erectile dysfunction. This task involved a complete review of the smoking literature as it pertained to erectile dysfunction and select endothelial diseases. MATERIALS AND METHODS: We comprehensively reviewed the literature, including PubMed and recent abstract proceedings from national meetings relevant to smoking, erectile dysfunction and endothelial diseases. The quality of the evidence was assessed by methods used to develop clinical practice guidelines. Our review involved an objective evaluation of the basic science literature and clinical studies. When necessary, we examined studies of endothelial diseases other than erectile dysfunction because of obvious gaps in the literature. RESULTS: There are strong parallels and shared risks among smoking, coronary artery disease, atherosclerosis and erectile dysfunction. Clinical and basic science studies provide strong indirect evidence that smoking may affect penile erection by the impairment of endothelium dependent smooth muscle relaxation. The association of erectile dysfunction with risk factors such as coronary artery disease and hypertension appears to be amplified by cigarette smoking. Smoking may increase the likelihood of moderate or complete erectile dysfunction 2-fold. The prevalence of erectile dysfunction in former smokers was no different from that in individuals who had never smoked, implying that smoking cessation may decrease the risk of erectile dysfunction. Case studies and retrospective series have shown an association of smoking with erectile dysfunction. CONCLUSIONS: Available evidence on the association of smoking with erectile dysfunction is not complete insofar as association linking factors are concerned. However, the evidence of such an association is likely due to the consistency of the relationship of smoking and endothelial disease, and the strength of the association of erectile dysfunction with other endothelial diseases.

Characterization and localization of nitric oxide synthase isoforms in the BB/WOR diabetic rat.

PURPOSE: Erectile dysfunction is a common pathological development in individuals with diabetes mellitus. Nitric oxide synthase (NOS) is essential for regulation of normal penile erection and NOS protein activity has been shown to be altered with diabetes. Several different isoforms and subtypes of NOS exist. However, little is known about how the distribution and abundance of these isoforms are altered with diabetes. We characterized the distribution and abundance of NOS isoforms and explored how they are altered with diabetes and result in erectile failure. MATERIALS AND METHODS: In situ hybridization and quantitative reverse transcriptase-polymerase chain reaction were done to measure the abundance and distribution of NOS-Ia, NOS-Ib, NOS-Ic, NOS-II and NOS-III in control and diabetic (BB/WOR) rats. Protein was localized by immunohistochemical analysis and alterations in protein abundance with diabetes were examined by Western blot analysis. RESULTS: NOS-I, NOS-II and NOS-III were observed in the endothelium lining the cavernous spaces and in the epithelium of the urethra. NOS-I protein was also present in the nerves of control and diabetic penes. We observed an increase in NOS-II expression around the dorsal nerves of diabetic penes, a decrease in NOS-III expression in diabetic pelvic ganglia and a decrease in NOS-Ib expression in the diabetic penis. NOS-I protein abundance was significantly decreased in diabetic pelvic ganglia. CONCLUSIONS: To our knowledge this is the first report of regional differences in the distribution of NOS-III in the urethra and altered NOS-Ib gene expression with diabetes.

Protein and gene expression of nitric oxide synthase isoforms I and III in the rat penile shaft.

Nitric oxide synthase (NOS) plays a key role in penile smooth muscle relaxation through the regulation of nitric oxide (NO). NO is a major neurotransmitter in the autonomic nervous system, and alteration of its activity has been implicated in erectile dysfunction. The objectives of this study were twofold: 1) to demonstrate and localize the NOS protein isoforms I and III in the normal rat penis, and 2) to identify and quantitate NOS I and III gene expression in the normal rat penis. The gene and protein product of NOS isoforms I and III are expressed in rat penile tissue. Protein expression of NOS I was confined primarily to neuronal tissue, while NOS III protein expression was identified primarily in both cavernosal smooth muscle and endothelium. The presence of both NOS I and III was confirmed in the penile shaft by Western blot. Quantitation of NOS I and III gene expression by reverse transcription-polymerase chain reaction revealed NOS III to be more highly expressed than that of NOS I in the rat penile shaft. NOS I and III protein and gene products are both expressed in normal rat penile tissue. Protein expression is localized primarily to neuronal tissue for NOS I, whereas NOS III is localized primarily to cavernosal smooth muscle and endothelium. NOS III gene expression is greater than that of NOS I in the normal rat penile shaft. These findings support the possibility that penile erection is regulated by different NOS isoforms released from neural, endothelial, and smooth muscle sources.

Analysis of NOS isoform changes in a post radical prostatectomy model of erectile dysfunction.

Optimal treatment of erectile dysfunction (ED) following radical prostatectomy remains a subject of much controversy and is a significant concern for prostate cancer patients requiring surgical intervention. Neural stimulation involving nitric oxide synthase (NOS) is a crucial aspect of the normal erection process. In this study NOS isoform interaction was evaluated to improve our understanding of molecular changes pertaining to erection post radical prostatectomy. Bilateral cavernous nerve (CN) resected and control adult male Sprague-Dawley rats were killed 7, 14 and 21 days after injury. RT-PCR, in situ hybridization, Western blot and immunohistochemical analysis were used to evaluate changes in NOS isoform expression and distribution. NOS-I protein was dramatically decreased after CN injury while NOS-III and NOS-II remained unchanged. A profound decrease in smooth muscle and endothelium was observed in the corpora. To our knowledge this is the first report of differential altered NOS isoform protein abundance under conditions which mimic radical prostatectomy. These results show the importance of maintaining at least partial innervation of the penis after surgical intervention and that endothelial and smooth muscle changes resulting from loss of innervation may account for the ED observed in prostatectomy patients.

Testosterone supplementation for erectile dysfunction: results of a meta-analysis.

PURPOSE: To our knowledge a causal relationship between altered levels of androgens and erectile dysfunction has not yet been established. We reviewed the literature to assess the usefulness of androgen replacement for erectile dysfunction. MATERIALS AND METHODS: Meta-analysis was chosen as the method of evaluating the literature. Study inclusion criteria were testosterone given as the only therapy for erectile dysfunction and a clearly stated definition of response for evaluating treatment success or failure. RESULTS: We evaluated 73 articles obtained by a MEDLINE search of 1966 to 1998 and included 16 in our study. The overall response rate was 57%. In the 9 series with response rate by etiology patients with primary versus secondary testicular failure had a response rate of 64% versus 44% (p <0.001). Intramuscular and oral methods of delivery were equivalent with a response rate of 51.3% and 53.2%, respectively. However, the response to transdermal therapy was significantly different from that of intramuscular and oral treatment (80.9% versus 51.3% and 53.2%, respectively, p <0.001). The mean confidence level response for testosterone treatment was 16. 7% in the placebo and 65.4% in the treated group (p <0.0001). CONCLUSIONS: Our meta-analysis of the usefulness of androgen replacement therapy for erectile dysfunction indicates that the response rate for a primary etiology was improved over that for a secondary etiology, transdermal testosterone therapy was more effective than intramuscular or oral treatment, and intramuscular and oral treatments were equivalent. In addition, there was a statistically significant difference in favor of testosterone over placebo, implying a role for supplementation in select groups.

Sildenafil causes a dose- and time-dependent downregulation of phosphodiesterase type 6 expression in the rat retina.

OBJECTIVES: Some authors have advocated the daily use of sildenafil for prophylaxis against, or treatment of, erectile dysfunction. However, no information has been published to support such a dosage regimen. The safety profile of uninterrupted use of sildenafil has not been evaluated as it pertains to alteration of PDE type 6 in the retina. In the present study we investigated whether short- or long-term exposure to a variety of sildenafil doses affect the expression of an enzyme important in the normal phototransduction cascade. METHODS: Sustained-release sildenafil pellets were implanted in 120-day-old male rats with concentrations from 1-200mg. Rat retinal tissue was harvested 7, 14, and 29 days after implantation. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) using GAPDH as an endogenous internal standard was used to quantitate PDE type 6 gene expression. RESULTS: Expression of PDE type 6 was upregulated after 7 days with dosages < or =5 mg (P<0.02). Significant downregulation of PDE type 6 expression was first noted with high dose sildenafil 14 days after implantation (P<0.02). Expression of PDE type 6 was significantly and profoundly downregulated 29 days after implantation for all pellet formulations > or =10 mg (P<0.01). CONCLUSIONS: Sildenafil downregulates PDE type 6 expression in a dose- and time-dependent fashion. These findings support the explanation that PDE type 6 inhibition causes the dose-dependent clinical effects of visual disturbance in men taking sildenafil. Implications for long-term, daily use of sildenafil in men are not clear.

Topical prostaglandin E1 SEPA gel for the treatment of erectile dysfunction.

PURPOSE: We compare the systemic effects, local tolerance and effectiveness of topical gel formulations on the penis containing alprostadil (prostaglandin E1) plus 5% SEPA versus SEPA alone (placebo) in men with erectile dysfunction. MATERIALS AND METHODS: Erectile response, skin discomfort and erythema were measured in 48 men with erectile dysfunction secondary to vascular, neurogenic, psychogenic or mixed etiologies in this single-blind, placebo controlled trial. RESULTS: Application of prostaglandin E1 gel correlated positively with erectile response as 67 to 75% of patients had an erection compared to 17% of controls (p<0.001). Blood pressure and heart rate varied minimally. No serious adverse effects were observed in the 48 patients, although the majority had skin discomfort. CONCLUSIONS: Topical prostaglandin E1 gel applied to the penis appears to be safe, and facilitates audiovisual and tactile stimulation resulting in an erection when given in a clinic setting. Consequences to the female partner remain unknown.