The pharmacological treatment of premature ejaculation

Levosulpiride for Premature Ejaculation: A Systematic Review and Meta-Analysis

Premature ejaculation (PE) is one of the major causes of sexual dysfunction. Levosulpiride is an off-label medicine used to treat PE, but no review on its efficacy exists. A systematic review and meta-analysis was performed to determine the efficacy of levosulpiride in treating PE. Databases PubMed, Science Direct, and Google Scholar were searched. Randomized control trials (RCTs) comparing levosulpiride with placebo or other medicine were selected. Odds ratio (OR) of improved intravaginal ejaculation latency time (IELT) was calculated. A total of 97 articles were retrieved from database search, of which only four RCTs containing 203 men met the selection criteria. All four RCTs were included in systematic review while only two were included in meta-analysis. A high selection and detection bias was found in both of these studies. Meta-analysis also showed the odds of improving IELT in PE patients using levosulpiride to be significantly higher (p < .05) compared with those who used placebo, OR: 100.81, 95% confidence interval (CI) [13.12-774.90], I2 = 0%. Odds of improving IELT for > 5 min (500% improvement) were also significantly higher (p < .05) compared with the placebo groups (OR: 38.88, 95% CI [5.12-295.29], I2 = 0%). The odds of improving IELT for > 1 min, but < 5 min were also significantly higher (p < .05) than placebo groups (OR: 32.84, 95% CI [4.15-259.75], I2 = 0%). Levosulpiride improved IELT, but even so, limited studies are available on this topic. Additional research is thus required to support the present review's findings.

Alpha1-adrenergic antagonists block 6-nitrodopamine contractions on the rat isolated epididymal vas deferens

6-nitrodopamine (6-ND) is released from rat isolated vas deferens and modulates electrical-field stimulation (EFS) contractions of the rat isolated epididymal vas deferens (RIEVD) via a specific receptor which is blocked by tricyclic antidepressants. Here, the effects of selective α1-adrenergic receptor antagonists on RIEVD contractions induced by 6-ND, dopamine, noradrenaline, adrenaline and EFS were investigated. Doxazosin and tamsulosin (3-10 nM) caused significant rightward shifts of the concentration-response curve to 6-ND, but had no effect on dopamine-, noradrenaline- and adrenaline-induced contractions. Alfuzosin (10 nM) produced rightward shifts on concentration-response curves to all catecholamines. Silodosin (10 nM) and terazosin (100 nM) displaced to the right the noradrenaline, dopamine and adrenaline curves, but higher concentrations of both antagonists (100 and 300 nM, respectively) were required to displace the 6-ND curves. The EFS-induced contractions were significantly inhibited only at the concentrations that the α1-adrenergic receptor antagonists caused rightward shifts on the 6-ND concentration-response curves. The inhibition of EFS-induced contractions by doxazosin (10 nM), tamsulosin (10 nM), alfuzosin (10 nM), silodosin (100 nM) and terazosin (300 nM), were not observed in RIEVD obtained from animals chronically treated with L-NAME. This work demonstrates that α1-adrenoceptor antagonists act as 6-ND receptor antagonists in RIEVD, opening the possibility that many actions previously attributed to noradrenaline could be due to 6-ND antagonism. In addition, blockade of the 6-ND receptors by both tricyclic antidepressants and α1-adrenergic receptor antagonists may represent the common mechanism of action responsible for their therapeutic use in the treatment of premature ejaculation.

A systematic review and meta-analysis of randomized controlled trials of "on-demand" use of tramadol vs "on-demand" use of paroxetine in the management of patients with premature ejaculation

AIM

To evaluate the effect of "on-demand" use of tramadol vs "on-demand" use of paroxetine in the management of patients with premature ejaculation (PE).

MATERIALS AND METHODS

A systematic search of PubMed, EMBASE, Cochrane Library databases and original references of the included articles was performed. PRISMA checklist was followed. The Cochrane Handbook was used to evaluate the quality of the included research.

RESULTS

A total of seven articles including 663 patients were studied. The results indicated that patients who received on-demand therapy of tramadol or paroxetine showed significant improvement compared with those treated with placebo, as assessed by intravaginal ejaculatory latency time (IELT) (P < .00001 and P = .02, respectively) and sexual satisfaction score (P < .00001 and P < .00001, respectively). Furthermore, Patients who were treated with on-demand tramadol had a better effect than those treated with on-demand paroxetine in respect of IELT (P = .01) and sexual satisfaction score (P = .03). With regard to safety, the most common adverse event for the tramadol group was sleep disturbance and the most common adverse event for the paroxetine group was a headache. No serious adverse event was observed in both groups.

CONCLUSIONS

Compared with placebo, on-demand therapy of tramadol or paroxetine showed a better improvements in IELT and sexual satisfaction scores. Besides, on-demand tramadol revealed a better effect than on-demand paroxetine for patients with PE, and patients in both groups showed good tolerance.

Comparative effect of administration and discontinuation of sildenafil and/or clomipramine on the hepatic, cardiac and testicular tissues of male rats

In this study, we examined the adverse consequences of prolonged treatment with sildenafil and/or clomipramine (CLO) on the hepatic, cardiac and testicular tissues of rats. Additionally, we investigated the potential effects of treatment discontinuation. To this end, 60 adult male rats were randomly assigned into six groups and were orally treated with 4.5 mg sildenafil /kg BW (SLD) and 9 mg/ kg BW (SHD), 2.25 mg CLO/kg BW (CLO), 4.5 mg sildenafil/kg BW + 2.25 mg CLO/kg BW (SLD-CLO) and 9 mg sildenafil/kg BW + 2.25 mg CLO/kg BW (SHD-CLO) while the control rats received 0.5 ml distilled water for 8 weeks. Then, five rats from each group were sacrificed and the other five rats were left untreated for another four weeks to recover from the drug treatment. Long-term administration of sildenafil and/or CLO led to oxidative stress, inflammation and structural changes in the liver, heart and testis, reduction in sperm count and motility, an increase in abnormalities, and a reduction in serum testosterone, FSH and LH levels. All tested parameters returned to the normal state following the four-week discontinuation of sildenafil. Additionally, all the alterations caused by long-term administration of CLO, SLD-CLO and SHD-CLO were significantly improved during the recovery period.

A Randomized Double-Blind Placebo-Control Study to Assess the Efficacy and Safety of OLNP-05 Versus Placebo for the Treatment of Subjects with Premature Ejaculation

Premature ejaculation (PE) is one of the foremost sex-related health problems among men. The global occurrence ranges from 20% to 30%, according to various studies. PE has a great impact on the men's quality of life, with deleterious effects such as embarrassment, frustration, and feeling of incompetence. Considering the necessity of treatment of PE, this study was planned to compare the efficacy and safety of OLNP-05 versus placebo for treating subjects suffering from PE. In this randomized clinical study, 60 men with PE were enrolled and randomly assigned to receive either OLNP-05 or placebo one capsule twice daily for a period of 8 weeks. Subjects were evaluated during visits on day 1, day 28, and day 56. Mean change from baseline in intravaginal ejaculatory latency time (IELT), improvement in premature ejaculation profile (PEP), and Clinical Global Impression-Improvement scale (CGI-I) were used to assess the efficacy of treatment. P-value <.05 was considered significant. At the end of the treatment, the improvement in IELT score in the OLNP-05 group was remarkably higher than the placebo. Subjects in the OLNP-05 treatment group also reported significantly greater improvement in PEP subscale score. Majority of OLNP-05-treated subjects were found to be in the "much improved" category as per CGI-I assessment. The result confirms the safety and efficacy of OLNP-05, therefore suggesting that OLNP-05 may be a safe and effective intervention for the management of PE. Trial registration: Clinical Trials Registry India (Registration No: CTRI/2017/08/009226, 02/08/2017).

Progresses in pharmaceutical and surgical management of premature ejaculation

OBJECTIVE

Premature ejaculation (PE) is regarded as one of the most common male sexual dysfunctions. This review introduced several pharmaceutical and surgical methods for the management of PE. The definition, etiology, behavioral, and psychological therapy of PE were also discussed.

DATA SOURCES

"Premature," "ejaculation," or "sexual dysfuction" were used as the medical subject headings (MeSH) to obtain relevant articles before June 2019 on Pubmed, Google Scholar and CNKI. Most articles used were written in English and several Chinese articles were also cited.

STUDY SELECTION

Full-text articles of retrospective/prospective/randomized controlled trials were analyzed. Animal experiments and letters were excluded.

RESULTS

There are four PE sub-types: lifelong PE, acquired PE, natural variable PE, and subjective PE. Behavioral therapy, psychotherapy, medication, topical anesthetics, and surgery are currently used for the treatment of PE. However, all the above treatments have limitations. Therefore, novel ways should be investigated to more efficiently control PE.

CONCLUSIONS

The pharmaceutical therapy that is currently being used in clinical practice for the management of PE is still the main choice globally due to its good efficacy. Surgery may be a choice for patients who are resistant to medication. However, it should be performed cautiously.

Which of available selective serotonin reuptake inhibitors (SSRIs) is more effective in treatment of premature ejaculation? A randomized clinical trial

Purpose:

To compare the efficacy and safety of available selective serotonin reuptake inhibitors (SSRIs) in order to find the most effective drug with the least number of side effects in treatment of premature ejaculation (PE).

Materials and Methods:

This study was a randomized clinical trial. Four hundred and eighty patients with PE in the 4 groups referred to Imam Reza hospital Tehran, Iran from July 2018 to February 2019 were enrolled in the study. The patients received sertraline 50mg, fluoxetine 20mg, paroxetine 20mg and citalopram 20mg, every 12 hours daily. The intravaginal ejaculatory latency time (IELT) before treatment, fourth and eighth weeks after treatment was recorded by the patient's wife with a stopwatch.

Results:

Mean IELT before, 4 and 8 weeks after treatment in four groups were: sertraline 69.4±54.3, 353.5±190.4, 376.3±143.5; fluoxetine 75.5±64.3, 255.4±168.2, 314.8±190.4; paroxetine 71.5±69.1, 320.7±198.3, 379.9±154.3; citalopram 90.39±79.3, 279.9±192.1, 282.5±171.1 seconds, respectively. The ejaculation time significantly increased in all groups (p <0.05), but there was no significant difference between the groups (P=0.75). Also, there was no significant difference in drugs side effects between groups (p >0.05). The most common side effects were drowsiness and dyspepsia, which were not severe enough to cause discontinuation of the drug.

Conclusions:

All available SSRIs were effective and usually had no serious complications. In patients who did not respond to any of these drugs, other SSRI drugs could be used as a salvage therapy.

Compliance With Fluoxetine Use in Men With Primary Premature Ejaculation

BACKGROUND

Premature ejaculation (PE) is a common sexual dysfunction for which selective serotonin reuptake inhibitors (SSRIs) have been used effectively for treatment. However, compliance with therapy and predictors of long-term SSRI use in the treatment of PE are not well known.

AIM

To analyze our experience with drop-out rates with fluoxetine in the primary PE population and to identify predictors of continued use of this agent.

METHODS

Men with primary PE constituted who used fluoxetine and had at least 12 months follow-up constituted the study population. Subjects underwent a comprehensive interview to ascertain self-reported (non-stopwatch) intravaginal ejaculatory latency time (IELT), self-rated control over ejaculation, and personal and patient-reported partner distress due to PE. Patients were treated with fluoxetine 20 mg daily, with the possibility of dose titration up or down based on efficacy and side effects.

OUTCOMES

The PE parameters of interest included self-reported IELT, self-rated control over ejaculation, personal and partner distress due to PE, and medication adherence.

RESULTS

130 men were included in the study. Dropout rates at 6 and 12 months were 56% and 72%. Self-rated "poor" ejaculatory control decreased from 98%-41% (P < .01), high personal distress from 47%-11% (P < .01), and high partner distress rates from 72%-27% (P < .01). Predictors of continued use at 12 months included high partner distress, being unpartnered, and having a post-treatment IELT ≥5 minutes (P < .01). Overall side effects included headache (5%), dizziness (4%), nausea (5%), nervousness (5%), and sleepiness (8%); however, moderate to severe side effects reported included nausea (2%), sleepiness (2%), headache (2%), and dizziness (2%).

CLINICAL IMPLICATIONS

Compliance with SSRIs is a well-described problem in the depression literature, but data are sparse regarding continued use of SSRIs in the treatment of PE.

STRENGTHS AND LIMITATIONS

We report on 12-month compliance with SSRIs for the treatment of PE. Our early compliance rates were more encouraging than what has been reported in the past. However, IELT was self-reported and not measured objectively, and we did not use validated patient-reported outcomes but rather self-reported ejaculatory control and distress levels, which have limitations.

CONCLUSIONS

Fluoxetine is an effective agent for the treatment of PE with significant improvement realized in IELT, ejaculatory control, and distress levels for both men and their partners. Despite its efficacy, continued use of fluoxetine beyond 6 months is poor. Jenkins LC, Gonzalez J, Tal R, et al. Compliance with Fluoxetine Use in Men with Primary Premature Ejaculation. J Sex Med 2020;16:1895-1899.

Fluoxetine-induced androgenic failure impairs the seminiferous tubules integrity and increases ubiquitin carboxyl-terminal hydrolase L1 (UCHL1): Possible androgenic control of UCHL1 in germ cell death?

The selective serotonin reuptake inhibitor fluoxetine has been used for the treatment of depression. Although sexual disorders have been reported in male patients, few studies have demonstrated the fluoxetine effect on the reproductive histophysiology, and the target of this antidepressant in testes is unknown. We evaluated the impact of short-term treatment with fluoxetine on the adult rat testes, focusing on steroidogenesis by Leydig cells (LC) and androgen-dependent testicular parameters, including Sertoli cells (SC) and peritubular myoid cells (PMC). Since UCHL1 (ubiquitincarboxyl-terminal hydrolase L1) seems to control spermatogenesis, the immunoexpression of this hydrolase was also analyzed. Adult male rats received 20 mg/kg BW of fluoxetine (FG) or saline (CG) for eleven days. In historesin-embedded testis sections, the seminiferous tubule (ST) and epithelial (Ep) areas, and the LC nuclear diameter (LCnu) were measured. The number of abnormal ST, androgen-dependent ST, SC and PMC was quantified. Testicular β-tubulin levels and peritubular actin immunofluorescence were evaluated. Serum testosterone levels (STL) and steroidogenesis by 17β-HSD6 immunofluorescence were analyzed, and either UCHL1-immunolabeled or TUNEL-positive germ cells were quantified. In FG, abnormal ST frequency increased whereas ST and Ep areas, androgen-dependent ST number, LCnu, 17β-HSD6 activity and STL reduced significantly. TUNEL-positive PMC and SC was related to decreased number of these cells and reduction in peritubular actin and β-tubulin levels. In FG, uncommon UCHL1-immunoexpression was found in spermatocytes and spermatids, and the number of UCHL1-immunolabeled and TUNEL-positive germ cells increased in this group. These findings indicate that LC may be a fluoxetine target in testes, impairing PMC-SC integrity and disturbing spermatogenesis. The increase of UCHL1 in the damaged tubules associated with high incidence of cell death confirms that this hydrolase regulates germ cell death and may be controlled by androgens. The fertility in association with the androgenic status of patients treated with fluoxetine should be carefully evaluated.

Self-assembled biodegradable polymeric micelles to improve dapoxetine delivery across the blood-brain barrier

Background

Dapoxetine (DPX) is the drug of choice for the specific treatment of premature ejaculation. DPX is characterized by relatively low bioavailability (42%) and short half-life (1.5 h). The aim of this study was to improve DPX bioavailability and delivery across the blood–brain barrier (BBB) using a nanostructured DPX formulation for improved DPX efficacy and patient satisfaction.

Materials and methods

DPX-loaded polymeric micelles (PMs) formulations (F1–F3) were characterized for particle sizes, entrapment efficiencies, and Fourier transform infrared spectroscopic and transmission electron microscopic evaluations. In addition, diffusion profiles of the prepared formulations were investigated. Animal model pharmacokinetic parameters in plasma and brain tissues were investigated and compared with commercial DPX tablets.

Results

Particle size analysis revealed that formulations of DPX PMs showed a narrow range of 62.7±9.3–45.45±9.1 nm for F1–F3. In addition, DPX PMs showed a sustained release pattern with 91.27%±7.64%, 79.43%±7.81%, and 63.78%±5.05% of DPX content permeated after 24 h for F1, F2, and F3, respectively. Plasma pharmacokinetic parameters for DPX PMs showed significant increase (P<0.05) for the area under drug concentration–time curves in plasma and brain tissues compared with commercial DPX tablets.

Conclusion

DPX formulations in the form of PMs improved bioavailability and efficacy across the BBB. This DPX formulation provided improved brain delivery in order to enhance the convenience and compliance of patients.

The impact of severe mental disorders and psychotropic medications on sexual health and its implications for clinical management

Sexual dysfunction often accompanies severe psychiatric illness and can be due to both the mental disorder itself and the use of psychotropic treatments. Many sexual symptoms resolve as the mental state improves, but treatment-related sexual adverse events tend to persist over time, and are unfortunately under-recognized by clinicians and scarcely investigated in clinical trials. Treatment-emergent sexual dysfunction adversely affects quality of life and may contribute to reduce treatment adherence. There are important differences between the various compounds in the incidence of adverse sexual effects, associated with differences in mechanisms of action. Antidepressants with a predominantly serotonergic activity, antipsychotics likely to induce hyperprolactinaemia, and mood stabilizers with hormonal effects are often linked to moderate or severe sexual dysfunction, including decreased libido, delayed orgasm, anorgasmia, and sexual arousal difficulties. Severe mental disorders can interfere with sexual function and satisfaction, while patients wish to preserve a previously satisfactory sexual activity. In many patients, a lack of intimate relationships and chronic deterioration in mental and physical health can be accompanied by either a poor sexual life or a more frequent risky sexual behaviour than in the general population. Here we describe the influence of psychosis and antipsychotic medications, of depression and antidepressant drugs, and of bipolar disorder and mood stabilizers on sexual health, and the optimal management of patients with severe psychiatric illness and sexual dysfunction.

Promescent Has a Cytotoxic Impact on Fresh Human Sperm In Vitro

OBJECTIVE

To assess the impact of Promescent, a commonly used topical medication for premature ejaculation (PE), on human sperm motility, forward progression (FP), viability, and sperm DNA fragmentation (SDF) in vitro.

MATERIALS AND METHODS

Aliquots from specimens for diagnostic semen analyses from patients (n = 20) presenting to a couple's fertility center andrology laboratory for fertility testing were included after the full diagnostic semen analyses were performed. Samples that met the World Health Organization's fifth edition criteria as "normal" had Promescent applied to an aliquot of the sample and motility, FP, viability, and SDF were compared with an aliquot that was not treated with Promescent. Institutional review board exemption was obtained. Statistical analysis was performed by Student t test with a P value of <.05 considered as statistically significant.

RESULTS

Promescent had a cytotoxic effect on sperm, which resulted in a statistically significant decrease in mean motility, FP, and viability as compared with corresponding control group samples, which did not have Promescent applied. There was no statistically significant difference in SDF between the 2 groups.

CONCLUSION

PE is estimated to affect up to 39% of men and is one of the most common self-reported male sexual disorders. There is an overlap among men with PE and those trying to achieve a pregnancy, and Promescent is a commonly used topical treatment for PE. Although there was no difference in SDF between the 2 groups, Promescent had a cytotoxic impact on sperm.

A Place for Sexual Dysfunctions in an Empirical Taxonomy of Psychopathology

Sexual dysfunctions commonly co-occur with various depressive and anxiety disorders. An emerging framework for understanding the classification of mental disorders suggests that such comorbidity is a manifestation of underlying dimensions of psychopathology (or "spectra"). In this review, we synthesize the evidence that sexual dysfunctions should be included in the empirical taxonomy of psychopathology as part of the internalizing spectrum, which accounts for comorbidity among the depressive and anxiety disorders. The review has four parts. Part 1 summarizes the empirical basis and utility of the empirical taxonomy of psychopathology. Part 2 reviews the prima facie evidence for the hypothesis that sexual dysfunctions are part of the internalizing spectrum (i.e., high rates of comorbidity; shared cognitive, affective, and temperament characteristics; common neural substrates and biomarkers; shared course and treatment response; and the lack of causal relationships between them). Part 3 critically analyzes and integrates the results of the eight studies that have addressed this hypothesis. Finally, Part 4 examines the implications of reconceptualizing sexual dysfunctions as part of the internalizing spectrum, and explores avenues for future research.

Psychosexual disorders and dermatologists

Sexual problems that are psychological in origin, rather than physiological, are called psychosexual disorders. Multiple factors, such as general health of the patient, chronic illnesses, psychiatric/psychological disorders, and socio-cultural factors, alone or in combination can be attributed to the development of psychosexual dysfunctions. The symptoms of these disorders vary for each individual and differ with gender. These disorders may be categorized as sexual dysfunction, paraphilias, and gender identity disorders. Dermatologists are sometimes consulted for sexual dysfunctions in their routine practice by the patients visiting sexually transmitted infections (STI) clinics because a majority of the patients believe that these problems are caused by dysfunctions in the sex organs, and because people are hesitant to go to sexuality clinics and psychiatrists for such problems. Sometimes these patients are referred from other specialties such as urology or gynecology; most often, we attempt to search for STIs or other dermatoses on the genitalia and refer them back. We often underestimate the prevalence of sexual concerns of the patients or feel uncomfortable discussing matters of sexuality with them. Dermatologists should understand basic sexual medicine and ask patients for sexual problems. They should be trained to manage such patients accordingly. In this review, we will be focusing on sexual dysfunctions, their etiopathogenesis, and management from a dermatologist's perspective.

Dapoxetine and the treatment of premature ejaculation

Background

Premature ejaculation (PE) is the most common male sexual complaint. Off-label oral selective serotonin reuptake inhibitors (SSRIs) are commonly prescribed for the treatment of PE. Dapoxetine is a short-acting SSRI specifically designed for on-demand use. The objective of this communication is to summarize the clinical and physiological evidence regarding the role of the serotonergic pathway and specifically dapoxetine in the treatment of PE.

Methods

A PubMed search was conducted on articles reporting data on dapoxetine for the treatment of PE. Articles describing the pathophysiology and treatment options for PE were additionally included for review.

Results

The etiology of PE is multi-factorial in nature. There are many treatment options for PE such as psychological/behavioral therapy, topical anesthetic agents, phosphodiesterase type 5 (PDE-5) inhibitors, and tramadol hydrochloride. SSRIs play a major role in PE treatment. Animal and clinical studies in addition to its pharmacokinetic document dapoxetine’s clinical efficacy and safety for on-demand treatment of PE.

Conclusions

Dapoxetine demonstrates clinical efficacy and a favorable side effect profile. Dapoxetine is currently the oral drug of choice for on-demand treatment of PE.

Impact of Antidepressant Drugs on Sexual Function and Satisfaction

Pleasurable sexual activity is important in many human relationships and can provide a sense of physical, emotional and social well-being. Depressive symptoms and depressive illness are associated with impairments in sexual function and sexual dissatisfaction in untreated and treated patients. Most currently available antidepressant drugs are associated with development or worsening of sexual dysfunction in a substantial proportion of patients. Sexual difficulties during antidepressant treatment often resolve as depression lifts, but can persist over long periods, reducing self-esteem and affecting mood and relationships adversely. Sexual difficulties during antidepressant treatment typically have many possible causes but the incidence and nature of dysfunction varies between drugs. Many interventions can be considered when managing sexual dysfunction associated with antidepressants but no approach is 'ideal'. Because treatment-emergent sexual difficulties are less frequent with certain drugs, presumably related to differences in pharmacological properties, and since current interventions are suboptimal, a lower incidence of sexual dysfunction is a relevant tolerability target when developing novel antidepressants.

Genetic polymorphism in the serotonin transporter gene-linked polymorphic region and response to serotonin reuptake inhibitors in patients with premature ejaculation

OBJECTIVES

Serotonin plays a central role in ejaculation and selective serotonin reuptake inhibitors have been successfully used to treat premature ejaculation. Here, we evaluated the relationship between a polymorphism in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) and the response of patients with premature ejaculation to SSRI medication.

METHODS

Sixty-nine premature ejaculation patients were treated with 20 mg/d paroxetine for three months. The Intravaginal Ejaculatory Latency Time and International Index of Erectile Function scores were compared with baseline values. The patients were scored as having responded to therapy when a 2-fold or greater increase was observed in Intravaginal Ejaculatory Latency Time compared with baseline values after three months. Three genotypes of 5-HTTLPR were studied: LL, LS and SS. The appropriateness of the allele frequencies in 5-HTTLPR were analyzed according to Hardy-Weinberg equilibrium using the χ2-test.

RESULTS

The short (S) allele of 5-HTTLPR was significantly more frequent in responders than in nonresponders (p<0.05). Out of the 69 total PE patients, 41 patients (59%) responded to therapy. There was no significant difference in the International Index of Erectile Function score at the end of therapy between the responder and nonresponder groups. The frequencies of the L allele and S allele were 20% and 39%, respectively, in the responder group (p<0.05).

CONCLUSION

We conclude that premature ejaculation patients with the SS genotype respond well to selective serotonin reuptake inhibitor therapy. Further studies with large patient groups are necessary to confirm this conclusion.

On-demand use of tramadol, sildenafil, paroxetine and local anaesthetics for the management of premature ejaculation: A randomised placebo-controlled clinical trial

Objectives

To compare the clinical efficacy of the on-demand use of four drugs in the management of patients with premature ejaculation (PE), as the off-label use of selective serotonin-reuptake inhibitors and topical penile anaesthetics is frequently indicated for the management of patients with PE, and tramadol HCl and sildenafil citrate were also tried for managing this disorder, but with recommendations based on weak evidence.

Patients and methods

This was a single-centre, single-blind, placebo-controlled clinical trial conducted on 150 patients who had PE for >1 year. Patients were randomised equally into five groups. On-demand tramadol, sildenafil, paroxetine, local lidocaine gel or placebo was given for patients in groups 1–5, respectively. During the month before treatment, the intravaginal ejaculation latency time (IELT) and sexual satisfaction scores (on a 0–5-point scale) were measured and compared to the mean IELT and sexual satisfaction scores recorded during 4 weeks of on-demand drug administration, with monitoring of any possible side-effects.

Results

Tramadol-treated patients had a significantly longer mean (SD) IELT, of 351 (119) s, than the other groups. Local anaesthetic was significantly better than paroxetine in prolonging the IELT, at 278 (111) vs. 186 (65) s, respectively. The improvement in sexual satisfaction was significantly better in the sildenafil group, with a mean (SD) improvement of 2.9 (1) points, than in the paroxetine and local anaesthetic groups, at 2.2 (0.9) and 1.9 (0.9) points, respectively.

Conclusions

The four drugs significantly improved IELT values over placebo. Tramadol was associated with significantly longer IELT values, whilst sildenafil induced significantly better sexual satisfaction than the other drugs. The four drugs had tolerable side-effects.

Patients affected by premature ejaculation due to glans hypersensitivity refuse circumcision as a potential definite treatment for their problem

The diagnosis of premature ejaculation (PE) was based on a score > 8 at the PEDT five-item questionnaire. Local anaesthetic treatment (LAT) was the first-line therapy. Subjects who obtained a normalisation of EPDT score (≤8) were considered responders to LAT and even affected by lifelong PE due glans hypersensitivity. We proposed to patients not completely satisfied with LAT to undergo circumcision as a potential definitive treatment for PE. All patients received exhaustive information about potential benefits, limitations and complications. In case of refusal, each man was asked for the reasons of his choice. A total of 152 patients were recruited. Hundred and twenty-four patients among 152 (81.6%) positively responded to LAT. Among the 124 LAT responders, 21 (17%) were completely satisfied. The remaining 103 men experienced adverse reactions. It was proposed to such patients if they would be interested to a definitive form of treatment to resolve their problem. All the patients responded positively to this question. Only four patients among them (3.9%) accepted. The remaining 99 (96.1%) refused providing the following reasons of their choice: absence of guarantees 82.8%; irreversibility of the procedure creating a permanent body alteration 75.7%; costs of the procedure 12.1%; fear of potential complications 7%.

Reduced treatment-emergent sexual dysfunction as a potential target in the development of new antidepressants

Pleasurable sexual activity is an essential component of many human relationships, providing a sense of physical, psychological, and social well-being. Epidemiological and clinical studies show that depressive symptoms and depressive illness are associated with impairments in sexual function and satisfaction, both in untreated and treated patients. The findings of randomized placebo-controlled trials demonstrate that most of the currently available antidepressant drugs are associated with the development or worsening of sexual dysfunction, in a substantial proportion of patients. Sexual difficulties during antidepressant treatment often resolve as depression lifts but can endure over long periods and may reduce self-esteem and affect mood and relationships adversely. Sexual dysfunction during antidepressant treatment is typically associated with many possible causes, but the risk and type of dysfunction vary with differing compounds and should be considered when making decisions about the relative merits and drawbacks of differing antidepressants. A range of interventions can be considered when managing patients with sexual dysfunction associated with antidepressants, including the prescription of phosphodiesterase-5 inhibitors, but none of these approaches can be considered "ideal." As treatment-emergent sexual dysfunction is less frequent with certain drugs, presumably related to differences in their pharmacological properties, and because current management approaches are less than ideal, a reduced burden of treatment-emergent sexual dysfunction represents a tolerability target in the development of novel antidepressants.

Selective resection of dorsal nerves of penis for premature ejaculation

Premature ejaculation (PE) is one of the most prevalent male sexual dysfunctions. Selective resection of the dorsal nerve (SRDN) of penis has recently been used for the treatment of PE and has shown some efficacy. To further clarify the efficacy and safety of SRDN on PE, we performed a preliminary, randomized, placebo-controlled clinical observational study. Persons with the complaints of rapid ejaculation, asking for circumcision because of redundant foreskin, intravaginal ejaculation latency time (IELT) within 2 min, not responding to antidepressant medication or disliking oral medication were randomly enrolled in two groups. From April 2007 to August 2010, a total of 101 eligible persons were enrolled, 40 of them received SRDN which dorsal nerves of the penis were selectively resected, and those (n = 61) enrolled in the control group were circumcised only. IELT and the Brief Male Sexual Function Inventory (BMSFI) questionnaire were implemented pre- and post-operatively for the evaluation of the effect and safety of the surgery. There are no statistically significant differences in the baseline data including mean ages, mean IELTs, perceived control abilities and the BMSFI mean scores between the two groups. With regard to the post-operative data of the surgery, both IELTs and perceived control abilities were significantly increased after SRDN (1.1 ± 0.9 min vs. 3.8 ± 3.1 min for pre- and post-operative IELT, respectively, p < 0.01),whereas the post-operative results were not significantly improved for the control group (1.2 ± 0.7 min vs. 1.5 ± 1.1 min, p > 0.05). Also, there were no statistically significant differences both in BMSFI composite and subscale scores between the two groups after surgery. Hence, we conclude that SRDN is effective in delaying ejaculation and improving ejaculatory control, whereas erectile function is not affected. The results imply that SRDN may be an alternative method for the treatment of PE for some patients.

The hormonal control of ejaculation

Hormones regulate all aspects of male reproduction, from sperm production to sexual drive. Although emerging evidence from animal models and small clinical studies in humans clearly point to a role for several hormones in controlling the ejaculatory process, the exact endocrine mechanisms are unclear. Evidence shows that oxytocin is actively involved in regulating orgasm and ejaculation via peripheral, central and spinal mechanisms. Associations between delayed and premature ejaculation with hypothyroidism and hyperthyroidism, respectively, have also been extensively documented. Some models suggest that glucocorticoids are involved in the regulation of the ejaculatory reflex, but corresponding data from human studies are scant. Oestrogens regulate epididymal motility, whereas testosterone can affect the central and peripheral aspects of the ejaculatory process. Overall, the data of the endocrine system in regulating the ejaculatory reflex suggest that widely available endocrine therapies might be effective in treating sexual disorders in these men. Indeed, substantial evidence has documented that treatments of thyroid diseases are able to improve some ejaculatory difficulties.

Vas deferens smooth muscle responses to the nitric oxide-independent soluble guanylate cyclase stimulator BAY 41-2272

The nitric oxide-cGMP signaling pathway modulates the ejaculatory functions. The nitric oxide (NO)-independent soluble guanylate cyclase haem-dependent stimulator BAY 41-2272 potently relaxes different types of smooth muscles. However, no study investigated its effects in vas deferens smooth muscle. Therefore, we designed experiments to evaluate the in vitro relaxing responses of vas deferens to BAY 41-2272. The effects of prolonged oral intake with BAY 41-2272 in vas deferens contractions of rats treated chronically with the NO synthase inhibitor N(ω)-nitro-L-arginine methyl ester (L-NAME) were also investigated. BAY 41-2272 (0.001-100 μM) produced concentration-dependent relaxations in the prostatic and epididymal portions of vas deferens, an effect markedly reduced by the soluble guanylate cyclase inhibitor ODQ (100 μM). BAY 41-2272 significantly increased cGMP levels that were fully prevented by ODQ. In separate protocols, rats received L-NAME (20mg/rat/day) concomitantly with BAY 41-2272 (10mg/kg/day, 4 weeks), after which vas deferens contractions to electrical-field stimulation and noradrenaline were achieved. Electrical-field stimulation (1-32 Hz) evoked frequency-dependent contractions that were significantly enhanced in L-NAME-treated rats. Co-treatment with BAY 41-2272 fully reversed the increased contractile responses in L-NAME group. Noradrenaline (0.01-100 μM)-induced contractions were also greater in L-NAME-treated rats, and that was normalized by BAY 41-2272. In conclusion, BAY 41-2272 potently relaxes in vitro rat vas deferens smooth muscle and elevates the cGMP levels in an ODQ-sensitive manner. Moreover, prolonged oral intake with BAY 41-2272 restores the enhanced contractile vas deferens activity in rats treated with L-NAME. NO-independent soluble guanylate cyclase stimulators may be an alternative treatment for premature ejaculation.

Dapoxetine: an evidence-based review of its effectiveness in treatment of premature ejaculation

Premature ejaculation (PE) is a major issue in male sexual health. The global prevalence of PE is estimated to be between 20% and 40%, making it the most common sexual dysfunction in men. PE causes distress and reduced quality of life for patients and has a negative impact on interpersonal relationships. Historically, it has been treated with cognitive therapy, behavioral methods, and off-label use of selective serotonin reuptake inhibitors usually used to treat depression and other psychological disorders. Dapoxetine is a selective serotonin reuptake inhibitor specifically designed to treat PE. This paper reviews the current evidence for use of dapoxetine in the treatment of PE in adult men. There is substantial evidence that dapoxetine 30 mg or 60 mg taken “on-demand” results in a significant increase in intravaginal ejaculatory latency time when compared with placebo. Patient-reported outcomes are clearly improved relative to placebo following dapoxetine therapy, indicating greater control over ejaculation, more satisfaction with intercourse, less ejaculation-related distress, and, importantly, significantly reduced interpersonal difficulty. These data were supported by consistent reports of improvement in Clinical Global Impression of change in PE following treatment with dapoxetine. Further studies are needed to evaluate long-term efficacy and health economics. The unique pharmacology of dapoxetine makes it ideal for on-demand dosing, and the clinical evidence shows dapoxetine to be an efficacious and tolerable treatment for lifelong and acquired PE.

Cardiovascular safety profile of dapoxetine during the premarketing evaluation

The cardiovascular safety profile of dapoxetine, a novel selective serotonin reuptake inhibitor (SSRI) developed as an on-demand oral treatment for premature ejaculation (PE) in men, is evaluated. The cardiovascular assessment of dapoxetine was conducted throughout all stages of drug development, with findings from preclinical safety pharmacology studies, phase I clinical pharmacology studies investigating the effect of dapoxetine on QT/corrected QT (QTc) intervals in healthy men, and phase III, randomized, placebo-controlled studies evaluating the safety (and efficacy) of the drug. Preclinical safety pharmacology studies did not suggest an adverse electrophysiologic or hemodynamic effect with concentrations of dapoxetine up to 2-fold greater than recommended doses. Phase I clinical pharmacology studies demonstrated that dapoxetine did not prolong the QT/QTc interval and had neither clinically significant electrocardiographic effects nor evidence of delayed repolarization or conduction effects, with dosing up to 4-fold greater than the maximum recommended dosage. Phase III clinical studies of dapoxetine in men with PE indicated that dapoxetine was generally safe and well tolerated with the dosing regimens used (30mg and 60mg as required). Events of syncope were reported during the clinical development program, with the majority occurring during study visits (on site) on day 1 following administration of the first dose when various procedures (e.g. orthostatic maneuvers, venipunctures) were performed, suggesting that the procedures contributed to the incidence of syncope. This was consistent with previous reports showing that these and similar factors contribute to or trigger vasovagal syncope. Findings of the dapoxetine development program demonstrate that dapoxetine is associated with vasovagal-mediated (neurocardiogenic) syncope. No other associated significant cardiovascular adverse events were identified.

The effects of three phosphodiesterase type 5 inhibitors on ejaculation latency time in lifelong premature ejaculators: a double-blind laboratory setting study

Study Type--Therapy (RCT) Level of Evidence 1b. What's known on the subject? and What does the study add? Several authors have reported their experience with PDE5 inhibitors alone or in combination with selective serotonin re-uptake inhibitors for treating premature ejaculation. However, to our knowledge, this is the first laboratory design study to evaluate the effects of three PDE5 inhibitors throughout the ejaculation process in men with lifelong premature ejaculation. In this laboratory setting study PDE5 inhibitors seem to prolong ELT but the difference from placebo is significant only in vardenafil. The quality of penile rigidity is better with PDE5 inhibitors in the post-ejaculatory period but the difference is significant only in sildenafil and vardenafil.

OBJECTIVE

• To evaluate the effects of three phosphodiesterase type 5 (PDE5) inhibitors on the ejaculation process in men with lifelong premature ejaculation using a double-blind laboratory setting.

PATIENTS AND METHODS

• Eighty men with lifelong premature ejaculation, 20 in each group, received placebo, vardenafil (10 mg), sildenafil (50 mg) or tadalafil (20 mg) in a double-blind study design. Placebo or PDE5 inhibitor was ingested after at least 2 h fasting and non-smoking. The subjects were placed in a silent room immediately and real-time penile rigidity and tumescence was monitored. • Subjects read some magazines or newspapers without any sexually stimulating material for 1.5 h. At the end of this period audiovisual sexual stimulation began with a video film and after the 8th minute the subject began vibratory stimulation to the frenular area. • At the beginning of ejaculation the patient stopped stimulation. When the patient began and stopped stimulation, the light near the observer turned on and off and the observer calculated the ejaculation period with a chronometer. The elapsed time was the ejaculation latency time (ELT) in seconds. • There was no interaction between subjects and observer during the test. The ELT, and the qualities of base and tip rigidities during ELT and after ejaculation were calculated.

RESULTS

• Median age of patients was 29 (range 22-39) years and median duration of premature ejaculation was 60 (range 7-180) months and there was no significant difference between groups. Median duration of vibratory stimulation (ELT) of subjects who received placebo was 48.5 s: 53.5 s for sildenafil, 70.0 s for tadalafil and 82.5 s for vardenafil. Compared with the placebo group, ELT was significantly longer only in subjects receiving vardenafil (P = 0.019). • In the post-ejaculatory refractory period, times to last recorded base rigidities were significantly longer than placebo in vardenafil and sildenafil groups with better erection quality (P < 0.01 for each).

CONCLUSIONS

• The PDE5 inhibitors seem to prolong ELT and the quality of penile rigidity is better with PDE5 inhibitors in post-ejaculatory period. • These findings suggest that PDE5 inhibitors might have some beneficial effects in men with lifelong premature ejaculation.

Factors associated with ejaculatory and orgasmic dysfunction in men with erectile dysfunction: analysis of clinical trials involving the phosphodiesterase type 5 inhibitor tadalafil

OBJECTIVE

To determine frequencies of, and risk factors for, ejaculatory dysfunction (EjD) and orgasmic dysfunction (OD) in men with different degrees of erectile dysfunction (ED).

PATIENTS AND METHODS

Baseline data from 28 ED trials were integrated and analysed. The International Index of Erectile Function Question 9 (IIEF-Q9; 'When you had sexual stimulation or intercourse, how often did you ejaculate?') and IIEF-Q10 ('How often did you have the feeling of orgasm with or without ejaculation?') were used to evaluate ejaculatory and orgasmic functions. Responses of 'almost never or never' or 'a few times (much less than half the time)' were taken as evidence of EjD or OD, respectively, whereas responses of 'almost always or always' or 'most times (much more than half the time)' were taken as evidence of normal function. Estimates of the relative risks (RRs) of EjD or OD were determined for multiple patient characteristics.

RESULTS

Among 12,130 study participants with available data, only 5117 (42.2%) reported normal ejaculatory function, and 4321 (35.6%) normal orgasm, regardless of ED severity. Among subjects with poor ejaculatory function, 16.7% had mild ED, and among subjects with poor sensation of orgasm, 21.9% had mild ED. Frequencies of EjD and OD increased with increasing ED severity. Of the 5117 individuals with normal ejaculatory function, 796 (15.6%) had poor sensation of orgasm. Of the 4321 subjects with normal orgasm, 226 (5.2%) had poor ejaculatory function. Men with (vs without) EjD or OD tended to be younger: 53.7 vs 56.9 years and 54.2 vs 56.2 years, respectively. Factors associated with increased RRs of EjD and OD included cardiomyopathy (RR for EjD 1.74; RR for OD 1.59); cardiac failure (RR 1.40; 1.22); and baseline use (or history of use) of antipsychotics (RR 1.45; 1.30), selective serotonin reuptake inhibitors (RR 1.31; 1.27), and tricyclic antidepressants (RR 1.34; 1.28).

CONCLUSIONS

EjD and OD occurred at baseline in more than one in three men enrolled in tadalafil trials. Even men with mild ED reported EjD or OD. Further studies are warranted to better understand the impacts of EjD and OD on male sexuality and quality of life.

Therapeutic targets for premature ejaculation

Premature ejaculation (PE) is the most common male sexual complaint, and may exert a profound negative impact on the man's life and partnership. Using currently available treatment alternatives (e.g., selective serotonin uptake inhibitor, agents acting locally on the penis), PE can be treated in most, but not all patients. However, since long term success rates have been disappointing, and the only approved treatment so far is the short-acting selective serotonin re-uptake inhibitor dapoxetine, there is currently an intensive search for new treatment modalities. Selection of the most promising therapeutic targets from a host of current and potential candidates depends heavily on their roles in the pathophysiology of PE. Possible central nervous targets that will be discussed are serotonin transporters, and CNS receptors for 5-HT(IA) and 5-HT(1B), dopamine, oxytocin, opioids, neurokinin-1, and glutamate. Putative peripheral targets include α(1)-adrenoceptors, phosphodiestrase enzymes, Rho kinases, purinergic (P2X) receptors, and penile sensory nerves. It is clear that exploiting the full therapeutic potential of these targets will require additional basic and clinical research.

SLC6 neurotransmitter transporters: structure, function, and regulation

The neurotransmitter transporters (NTTs) belonging to the solute carrier 6 (SLC6) gene family (also referred to as the neurotransmitter-sodium-symporter family or Na(+)/Cl(-)-dependent transporters) comprise a group of nine sodium- and chloride-dependent plasma membrane transporters for the monoamine neurotransmitters serotonin (5-hydroxytryptamine), dopamine, and norepinephrine, and the amino acid neurotransmitters GABA and glycine. The SLC6 NTTs are widely expressed in the mammalian brain and play an essential role in regulating neurotransmitter signaling and homeostasis by mediating uptake of released neurotransmitters from the extracellular space into neurons and glial cells. The transporters are targets for a wide range of therapeutic drugs used in treatment of psychiatric diseases, including major depression, anxiety disorders, attention deficit hyperactivity disorder and epilepsy. Furthermore, psychostimulants such as cocaine and amphetamines have the SLC6 NTTs as primary targets. Beginning with the determination of a high-resolution structure of a prokaryotic homolog of the mammalian SLC6 transporters in 2005, the understanding of the molecular structure, function, and pharmacology of these proteins has advanced rapidly. Furthermore, intensive efforts have been directed toward understanding the molecular and cellular mechanisms involved in regulation of the activity of this important class of transporters, leading to new methodological developments and important insights. This review provides an update of these advances and their implications for the current understanding of the SLC6 NTTs.

NET occupancy by clomipramine and its active metabolite, desmethylclomipramine, in non-human primates in vivo

RATIONALE

Norepinephrine transporter (NET) is one of the key targets for antidepressants such as combined serotonin and norepinephrine reuptake inhibitors as well as some of the tricyclic antidepressants. Clomipramine, a tricyclic antidepressant, has been reported to have an active metabolite, desmethylclomipramine, which has high affinity for NET in vitro. However, the NET occupancy of clomipramine and desmethylclomipramine has not fully been evaluated in vivo.

OBJECTIVES

In this positron emission tomography (PET) study, we investigate NET occupancy by clomipramine and desmethylclomipramine, respectively, in non-human primates with a selective radioligand for NET, (S,S)-[(18)F]FMeNER-D(2).

METHODS

PET measurements were performed with (S,S)-[(18)F]FMeNER-D(2) at baseline and after the intravenous administration of clomipramine and desmethylclomipramine, respectively. NET binding was calculated with the simplified reference tissue model using the caudate as reference region. NET occupancy was calculated as the difference in NET binding between the baseline and pretreatment condition. The relationship between NET occupancy and dose/plasma concentration was evaluated using hyperbolic functions.

RESULTS

NET occupancy by both clomipramine and desmethylclomipramine increased in a dose and plasma concentration-dependent manner. The mean Kd values, expressed as the dose or plasma concentration at which 50% of NET was occupied, were 0.44 mg/kg and 24.5 ng/ml for clomipramine and 0.11 mg/kg and 4.4 ng/ml for desmethylclomipramine.

CONCLUSIONS

Not only desmethylclomipramine but also clomipramine was demonstrated to occupy NET in the non-human primate in vivo. It can thus be assumed that NET occupancy during clinical treatment with clomipramine is a combined effect of unchanged clomipramine and its main metabolite desmethylclomipramine.

The serotonin transporter plays an important role in male sexual behavior: a study in serotonin transporter knockout rats

INTRODUCTION

Serotonin (5-HT) is an important neurotransmitter for sexual behaviors. Heterozygous (+/-) serotonin transporter (SERT) rats and SERT knockout rats (-/-) have serotonergic disturbances with significant elevations of basal extracellular 5-HT levels.

AIM

To investigate the putative role of the SERT in male sexual behavior.

METHODS

After extensive sexual training, the effects of the 5-HT(1A/7) receptor agonist ± 8-OH-DPAT, the 5-HT(1A) receptor antagonist WAY100 635 and a combination of both on sexual behaviors of SERT(-/-) and SERT(+/-) knockout and wildtype (SERT(+/+) ) male Wistar rats were examined.

MAIN OUTCOME MEASURES

Male rat sexual behaviors of mounts, intromissions, and ejaculations.

RESULTS

SERT(-/-) had lower basal ejaculation frequencies than SERT(+/-) and SERT(+/+) animals. ± 8-OH-DPAT enhanced sexual performance in all three genotypes to the same extent. WAY100635 dose-dependently inhibited sexual behavior in all three genotypes with significant dose to genotype interactions. WAY100635 exerted the strongest effects in SERT(-/-) animals. The combination of a dose range of ± 8-OH-DPAT and a selected dose of WAY100635 revealed only partial antagonism by ± 8-OH-DPAT of the sexual inhibitory effects of WAY100635.

CONCLUSIONS

Absence of the serotonin transporter reduces basal ejaculatory performance in male rats. Pharmacological experiments suggest that separate pools of 5-HT(1A) receptors regulate different aspects of sexual performance in male rats. 5-HT(7) receptors may play a minor role in the partial recovery of sexual behavior after combination of ± 8-OH-DPAT and WAY100635. The SERT(-/-) rat may be a model for chronic SSRI treatment, delayed ejaculation, anorgasmia, and/or low libido.

Activation of NMDA receptors in lumbar spinothalamic cells is required for ejaculation

INTRODUCTION

The sexual reflex ejaculation is controlled by a spinal ejaculation generator located in the lumbosacral spinal cord. A population of spinothalamic (LSt) neurons forms a key component of this generator, as manipulations of LSt cells either block or trigger ejaculation. However, it is currently unknown which afferent signals contribute to the activation of LSt cells and ejaculation.

AIM

The current study tested the hypothesis that glutamate, via activation of N-Methyl-D-aspartic acid (NMDA) receptors in LSt cells, is a key regulator of ejaculation.

METHODS

Expression of phosphorylated NMDA receptor subunit 1 (NR1) was investigated following mating, or following ejaculation induced by electrical stimulation of the dorsal penile nerve (DPN) in anesthetized, spinalized male rats. Next, the effects of intraspinal delivery of NMDA receptor antagonist AP-5 on DPN stimulation-induced ejaculation were examined. Moreover, the ability of intraspinal delivery of NMDA to trigger ejaculation was examined. Finally, the site of action of NMDA was determined by studying effects of NMDA in male rats with LSt cell-specific lesions.

MAIN OUTCOME MEASURES

Expression of NR1 and phosphorylated NR1 in LSt cells was analyzed. Electromyographic recordings of the bulbocavernosus muscle (BCM) were recorded in anesthetized, spinalized rats following stimulation of the DPN and delivery of AP-5 or NMDA.

RESULTS

Results indicate that the NR1 receptors are activated in LSt cells following ejaculation in mating animals or induced by DPN stimulation in anesthetized, spinalized animals. Moreover, NR1 activation in LSt cells is an essential trigger for rhythmic BCM bursting, as DPN stimulation-induced reflexes were absent following administration of NMDA receptor antagonist in the L3-L4 spinal area, and were triggered by NMDA. NMDA effects were dependent on intact LSt cells and were absent in LSt-lesioned males.

CONCLUSION

These results demonstrate that glutamate, via activation of NMDA receptors in LSt cells, is a key afferent signal for ejaculation.

Experimental study on Satureja montana as a treatment for premature ejaculation

AIM OF THE STUDY

Satureja montana (winter savory) is a medicinal plant traditionally used to treat different disorders including male sexual dysfunction. In this study we evaluated the effect of Satureja montana hydroalcoholic extract on copulatory behavior of sexually potent male rats.

MATERIALS AND METHODS

The extract was orally administered acutely or repetitively for 8 consecutive days at the doses of 25 and 50 mg/kg. The main parameters of sexual behavior, mount (ML), intromission (IL), ejaculation (EL) latencies and post-ejaculatory interval (PEI), were evaluated in animals submitted to mating test and multiple ejaculations test. Testosterone serum levels were measured in rats acutely treated with Satureja montana extract dosed at 50 mg/kg. In addition the open field test was conducted to evaluate the locomotor behavior.

RESULTS

When acutely administered at both dosages, the extract was able to significantly increase EL and decrease intromission frequency (IF) in comparison with controls. The significant increase in EL was found also when the extract was subacutely administered, daily for 8 consecutive days, at the dose of 25 mg/kg. In the multiple ejaculations test, EL values of treated rats were significantly increased during the 1st and 2nd sequence in comparison with controls; in addition only rats treated with the extract were able to reach the 4th ejaculation within 30 min. Testosterone serum level measured in rats acutely treated with Satureja montana at the dose of 50 mg/kg was significantly increased in rats in comparison with controls. Finally, the locomotor activity recorded in the open field test was not affected by the acute administration of the plant extract.

CONCLUSIONS

These data suggest that Satureja montana could be considered as a natural remedy for the treatment of premature ejaculation delaying ejaculation latency without exerting any negative effect on the other parameters of sexual behavior and without exerting a sedative effect. In addition the increased serum level of testosterone confirms the positive influence of Satureja montana on male sexual function.

Update on treatments for premature ejaculation

Current and upcoming treatment options for premature ejaculation (PE) are of global clinical interest. In 2008, the International Society for Sexual Medicine published an evidence-based definition for PE. While there are no US Food and Drug Administration-approved therapies for PE, the American Urological Association 2004 guidelines state the serotonergic antidepressants paroxetine, sertraline, fluoxetine and clomipramine and the topical lidocaine-prilocaine cream are effective treatment options. However, there are limitations associated with their use, which may be overcome by PE-specific therapies currently in development. Two agents that are in advanced stages of clinical development include: (i) dapoxetine, an on-demand short-acting selective serotonin reuptake inhibitor, and (ii) PSD502, a metered-dose aerosol containing lidocaine and prilocaine, also for on-demand treatment. Another on-demand agent in development is tramadol, a weak opioid that is currently approved for treating pain. Coupled with efficient diagnosis, it is hoped that these newer agents will improve the quality of life for patients who suffer from PE.

Dapoxetine: in premature ejaculation

Dapoxetine, a selective serotonin reuptake inhibitor, is the first oral pharmacological agent indicated for the treatment of men aged 18-64 years with premature ejaculation. In four randomized, double-blind, placebo-controlled, multicentre studies of 12-24 weeks' duration, oral dapoxetine 30 or 60 mg (administered as needed) was effective in the treatment of men with premature ejaculation, inducing significantly (p < 0.001) greater improvements from baseline than placebo in the primary efficacy endpoint (mean intravaginal ejaculatory latency time [IELT] or mean average IELT [defined as the average of IELT values over the previous 4 weeks], as measured by the female partner utilizing a stopwatch). For the most part, dapoxetine recipients achieved significantly better outcomes than placebo recipients with regard to the secondary endpoints, including the Premature Ejaculation Profile (PEP) domains and the Clinical Global Impression or Patient Global Impression ratings of change in premature ejaculation, across these clinical studies. The beneficial effects of dapoxetine therapy on the perceived control over ejaculation and satisfaction with sexual intercourse PEP domains were sustained in a 9-month noncomparative extension phase of two identical 12-week, double-blind studies. Oral dapoxetine therapy for up to 12 months was generally well tolerated in men with premature ejaculation, with the nature of treatment-emergent adverse events generally similar across the clinical studies and between dapoxetine and placebo.