Premature ejaculation and serotonergic antidepressants-induced delayed ejaculation: the involvement of the serotonergic system

Differential effects of simultaneous or sequential administration of paroxetine and WAY-100,635 on ejaculatory behavior

Clinical treatment of depression or anxiety with selective serotonin reuptake inhibitors (SSRIs) often results in delayed ejaculation or anorgasmia. Co-treatment with subtype-selective serotonin receptor antagonists may alter the timing of onset of action and potentiate or reduce sexual side effects. Sexual behavior in male Sprague-Dawley rats was examined after acute administration of the SSRI, paroxetine and the serotonin1A antagonist, WAY-100,635. Acute administration of paroxetine alone did not alter male ejaculatory behavior. However, administration of paroxetine plus WAY-100,635 resulted in a significant delay in mounting behavior and increased the time to ejaculation. Simultaneous administration of paroxetine and WAY-100,635 produced a greater delay in initiation of mounting behavior and ejaculation compared to sequential administration of paroxetine followed by WAY-100,635. The differential effect on sexual behavior or addition of specific serotonin receptor antagonists may be relevant for clinical treatment therapies of premature ejaculation.

Does Lidocaine Ointment Addition Increase Fluoxetine Efficacy in the Same Group of Patients with Premature Ejaculation?

PURPOSE

To evaluate the efficacy of fluoxetine alone and fluoxetine+lidocaine ointment in the same patient group with premature ejaculation (PE).

MATERIAL AND METHODS

78 patients with PE were given 20 mg fluoxetine by an 'as-needed treatment' 4 h before planned sexual activity for a period of 3 months. They were then told to add local lidocaine ointment to fluoxetine 30 min before sexual activity for an additional 3 months for most of their sexual attempts. They were asked to note their PE grades and intravaginal ejaculatory latency time (IELT) scores by stopwatch technique before and after each treatment modality; the results were compared statistically afterwards.

RESULTS

Of 46 patients who completed the study, the mean pretreatment, fluoxetine alone and fluoxetine+lidocaine ointment treatment PE grades and IELT scores were found to be 6.52+/-1.42 and 2.58+/-0.49, 3.21+/-1.86 and 1.28+/-0.71, 2.17+/-1.56 and 1.04+/-0.72, respectively, showing a decrease in PE grades and IELT scores in combined therapy. On an individual patient basis, the total significant and moderate improvement rate of combined therapy was found to be 86.9%. Failure was observed in 6 (13.1%) patients.

CONCLUSION

The effective treatment with fluoxetine+lidocaine ointment offers the advantage of an 'as-needed treatment' in PE with minimal side effects and can be used as one of the first-line alternatives in the treatment of PE.

Physiology of Ejaculation: Emphasis on Serotonergic Control

Ejaculation is constituted by two distinct phases, emission and expulsion. Orgasm, a feature perhaps unique in humans, is a cerebral process that occurs, in normal conditions, concomitantly to expulsion of semen. Normal antegrade ejaculation is a highly coordinated physiological process with emission and expulsion phases being under the control of autonomic and somatic nervous systems respectively. The central command of ejaculation is located at the thoracolumbar and lumbosacral levels of the spinal cord and is activated by stimuli from genital, mainly penile, origin although cerebral descending pathways exert both inhibitory and excitatory regulatory roles. Cerebral structures specifically activated during ejaculation form a tightly interconnected network comprising hypothalamic, diencephalic and pontine areas. A rational neurobiological approach has led to identify several neurotransmitters contributing to the ejaculatory process. Amongst them, serotonin (5-HT) has received strong experimental evidences indicating its inhibitory role in the central control of ejaculation. In particular, 5-HT1A cerebral autoreceptors but also spinal 5-HT1B and, in a lesser extent, 5-HT2C receptors have been shown to mediate the effects of 5-HT on ejaculation. Pharmacological strategies, especially those targeting serotonergic system, for the treatment of ejaculatory disorders in human will undoubtedly benefit from the application of basic and clinical research findings. In this perspective, the use of selective serotonin reuptake inhibitors (SSRIs) which basically increase the amount of central 5-HT and delay ejaculation in humans seems promising.

Proposals or Findings for a New Approach about How to Define and Diagnose Premature Ejaculation

PURPOSE

To review and present the proposals or findings for a new approach about how to define and diagnose premature ejaculation (PE).

MATERIALS AND METHODS

Using Medline to search for international peer reviewed manuscripts published from 1996 to 2004 about the definition and diagnosis of PE.

RESULTS

PE, to date, has not a universally agreed definition and diagnostic criterion. Many definitions are partial, subjective and nonspecific. An ideal definition or diagnostic criterion should consist of intravaginal ejaculatory latency time (IELT), the ability to control over ejaculation, the extent of male sexual satisfaction, the extent of female sexual satisfaction, the frequency of female sexual partner reaching orgasm and the extent of psychological and pathological factors. Therefore, the Chinese Index of Premature Ejaculation (CIPE) seems an ideal tool and criterion used to diagnose PE due to including all the elements above. In the majority of cases, PE is the result of a mix of psychogenic, physiological and organic factors. So, besides some routine tests such as urine routine test, endocrine hormone assay, psychosexual counseling, couple evaluation and physical examination, prostate examination, serum leptin assay, semen magnesium assessment and glans hypersensitivity measurement, are suggested to be performed in the diagnosis of PE. Although elucidated by two clinical trials and further confirmed, serum leptin assay seems a promising and objective marker to diagnose PE because it is related to the serotonergic system whose disorder has been confirmed to contribute to the etiology of PE.

CONCLUSION

None of these definitions and diagnoses has been accepted as a universal agreement of PE. CIPE seems an ideal tool and criterion used to diagnose PE and leptin maybe become a promising and objective marker for PE.

[Use of paroxetine on-demand in premature ejaculation]

INTRODUCTION

It has been described varied definitions of premature ejaculation (PE), which has determined different prevalences and rates of success for the different therapies with selective serotonin re-uptake inhibitors. Our goal was evaluate the effectiveness of paroxetine like treatment of premature ejaculation administered on-demand (4-6 hours previous to intercourse) compared to the scheme of daily dose.

PATIENTS AND METHOD

A prospective study type crossover was designed with 14 patients. Grupo A: 7 patient received paroxetine 20 mg/d by three weeks followed by paroxetine 20 mg 4-6 hours before the intercourse by three weeks. Group B: the other 7 patients received the same scheme but replacing by placebo. Later to three weeks of therapy suspension, crossover was made.

RESULTS

The intravaginal ejaculatory latency time (IELT) pre-treatment was 0.4 minutes. In the group A the IELT average was of 4.3 minutes in the treatment with daily paroxetine; 5.8 minutes when they received paroxetine on-demanad; 0.9 with daily placebo and 0.6 with placebo on-demand (p < 0.001). For group B the IELT during the daily placebo was 0.8 minutes and with placebo on-demand it was of 1.1. When they received daily paroxetine the IELT was 3.3 minutes and during the phase of paroxetine on-demand it was increased to 6.1 (p<0.001).

CONCLUSIONS

The treatment of premature ejaculation with paroxetine in daily dose and scheme on-demand appears similar like effective options.

Individual differences in male rat ejaculatory behaviour: searching for models to study ejaculation disorders

In addition to investigating sexual function in rats that display normal ejaculatory behaviour, studying rats that are either 'hyposexual' or 'hypersexual' may provide important insights into the aetiology of ejaculatory dysfunctions in men, such as premature and retarded ejaculation. To this end, rats were matched into groups of 'sluggish', 'normal' and 'rapid' ejaculators based on their ejaculation frequencies displayed in a series of weekly sexual behaviour tests. Selecting rats on this parameter revealed large and stable differences in other parameters of sexual behaviour as well, including ejaculation latency and mount frequency but not intromission frequency and mount latency, putative indices of sexual motivation. Neuroanatomically, Fos immunoreactivity as a measure of neuronal activation was increased in rapid ejaculators compared with sluggish ejaculators in ejaculation-related brain areas, presumably associated with the differences in ejaculatory behaviour. Although the total number of oxytocin neurones within subregions of the hypothalamus did not differ between groups, in the supraoptic nucleus of the hypothalamus more oxytocin neurones were activated in rapid ejaculators compared with the other groups. Apart from the differences observed in ejaculatory behaviour, groups did not differ with respect to their locomotor activity and approach-avoidance behaviour as measured in the elevated plus-maze. Finally, apomorphine-induced stereotypy was similar in sluggish and rapid ejaculators, suggesting no large differences in dopamine susceptibility. Altogether, the present results suggest stable differences in male rat ejaculatory behaviour. Further exploring the neurobiological mechanisms underlying these differences may be a promising approach to gain insights into the aetiology of sexual dysfunctions such as premature, retarded or an-ejaculation.

Selective Serotonin-Reuptake Inhibitors in the Treatment of Premature Ejaculation

OBJECTIVE

To review the use of selective serotonin-reuptake inhibitors (SSRIs) in the treatment of premature ejaculation.

DATA SOURCES

Articles were retrieved through a MEDLINE search (1966–January 2004). Search terms used to identify articles included serotonin uptake inhibitors, premature ejaculation, rapid ejaculation, and sexual behavior, as well as the generic names of currently available SSRIs: fluoxetine, fluvoxamine, paroxetine, sertraline, citalopram, and escitalopram. The literature search was limited to articles published in the English language containing human subjects.

STUDY SELECTION AND DATA EXTRACTION

Articles obtained through the literature search were evaluated, and randomized controlled trials were included in this review. Information from noncontrolled trials or case reports was considered for inclusion if it contributed to the completeness of this review and if it was the highest level of evidence available.

DATA SYNTHESIS

Premature ejaculation is a commonly reported sexual difficulty. Delayed ejaculation is a widely reported sexual adverse effect of SSRIs. In some men exhibiting premature ejaculation, the ability of the SSRIs to delay ejaculation has been therapeutic. Trials evaluating the ejaculation-delaying ability of SSRIs demonstrated that paroxetine, fluoxetine, sertraline, and citalopram produce a statistically significant increase in the ejaculation latency time compared with placebo.

CONCLUSIONS

Taking advantage of the ejaculation-delaying effects of SSRIs increases the treatment options available to prescribers and patients. Convenience and minimal adverse effect profile make these agents an alternative to previously used behavior modalities and older pharmacologic agents. Although some questions still surround the details of their use, SSRIs have the potential to improve the quality of life for men with premature ejaculation and their partners.

Animal models of premature and retarded ejaculation

Most of our current understanding of the neurobiology of sexual behavior and ejaculatory function has been derived from animal studies using rats with normal sexual behaviour. However, none of these proposed models adequately represents human ejaculatory disorders. Based on the "ejaculation distribution theory", which postulates that the intravaginal ejaculation latency time in men is represented by a biological continuum, we have developed an animal model for the research of premature and delayed ejaculation. In this model, a large number of male Wistar rats are investigated during 4-6 weekly sexual behavioural tests. Based on the number of ejaculations during 30 min tests, rapid and sluggish ejaculating rats are distinguished, each representing approximately 10% at both ends of a Gaussian distribution. Together with other parameters, such as ejaculation latency time, these rats at either side of the spectrum resemble men with premature and delayed ejaculation, respectively. Comparable to the human situation, in a normal population of rats, endophenotypes exist with regard to basal sexual (ejaculatory) performance.

Lifelong premature ejaculation: definition, serotonergic neurotransmission and drug treatment

The ejaculation distribution theory (EDT) postulates a biological continuum of the intravaginal ejaculation latency time (IELT) in men. Such an continuum has recently been found in two epidemiological stopwatch studies. In addition, a continuum of ejaculation latency time has also been demonstrated in laboratory rats. It is suggested that the invariable parts of ejaculation, i.e. premature and retarded ejaculation are highly influenced by genetic and neurobiological factors. In contrast, superimposed on biological roots, ejaculation of men, in the middle part of the continuum, is probably more easily influenced by environmental and psychological factors. A meta-analysis of 35 daily SSRI and clomipramine treatment studies demonstrated a similar efficacy for paroxetine, clomipramine, sertraline and fluoxetine, with paroxetine exerting the strongest effect on ejaculation. Based on fundamental insights into serotonergic neurotransmission, it is suggested that on-demand conventional SSRI treatment will not lead to similarly impressive ejaculation delay as that found after daily conventional SSRI treatment. Future studies with SSRIs with short half-lives, short T(max) and high C(max )should elucidate whether these pharmacokinetic properties are able to affect the pharmacodynamics of 5-HT neurons in such a way that immediate clinically relevant ejaculation delay occurs.

Retarded ejaculation in men: an overview of psychological and neurobiological insights

Disorders of orgasm and ejaculation are erroneously mixed up in the DSM-IV classification system. Male Orgasmic Disorder to denote "delayed ejaculation" is inadequate as orgasm and ejaculation represent clinical expressions of different neurobiological phenomena. Unfortunately, the DSM-IV criteria for delayed ejaculation were accepted regardless of any research with appropriate methodology and design. The psychological approach and associated psychotherapy to solve this problem is rather disappointing. The neurobiological approach, which started with animal studies, has demonstrated various neurotransmitters with the potency to inhibit ejaculation. Indeed, several experimental drugs have been tested in rats, showing the successful acceleration of ejaculation. We propose that human research should start with the development of an operational definition of delayed ejaculation. To achieve this goal, we propose unselected epidemiological stopwatch studies which also provide information on the prevalence and incidence of delayed ejaculation in men. Currently, no effective and safe drugs are available to accelerate ejaculation time in men. The best way to treat lifelong delayed ejaculation is, thus far, to inform the patients about biological and psychological inhibiting factors which they need to avoid, and to remain critical about unrealistic expectations from psychotherapy. Psychotherapy may be useful in subgroups, particularly in the absence of effective and safe drugs.

Sexual Dysfunction and Lower Urinary Tract Symptoms (LUTS) Associated with Benign Prostatic Hyperplasia (BPH)

Sexuality is an essential aspect of a couple's relationship and has a significant impact on life satisfaction. Benign prostatic hyperplasia (BPH) is a condition that commonly affects older men and is often associated with lower urinary tract symptoms (LUTS) and sexual dysfunction. Men with moderate-to-severe LUTS are at increased risk for sexual dysfunction, including moderate-to-severe erectile dysfunction (ED), ejaculatory dysfunction (EjD), and hypoactive desire (HD). The results of several recent large-scale studies have shown a consistent and strong relationship between LUTS and both ED and EjD. It appears that the pathophysiological mechanisms of LUTS and the related prostatic enlargement of BPH as well as certain treatments for this condition may have an impact on both the erection and ejaculation components of the sexual response. Validated questionnaires that assess sexual function provide clinicians with valuable information to help guide treatment selection decisions. Effective medical therapies for LUTS associated with BPH include alpha(1)-adrenergic receptor antagonists (i.e., alfuzosin, doxazosin, tamsulosin, and terazosin) and 5alpha-reductase inhibitors (i.e., finasteride and dutasteride). The side effects of these medications, including sexual dysfunction, are important distinguishing features. The successful management of patients with LUTS associated with BPH should include assessments of sexual function and monitoring of medication-related sexual side effects. For men with LUTS and sexual dysfunction, an appropriate integrated management approach, based on each patient's symptoms and outcome objectives, is warranted.

Diagnosis and Treatment of Premature Ejaculation: The Physician's Perspective

Premature ejaculation (PE) is a common condition associated with significant adverse effects on the sexual and overall quality of life of men with this condition. Behavioral therapies, such as the "squeeze" and "stop-start" techniques, and psychotherapy, have been the mainstay of PE management for many years. However, evidence of their short-term efficacy is limited while support for their long-term benefit is lacking. There are currently no medications licensed specifically for the treatment of PE. This paucity of pharmacological treatment may, in turn, contribute to the absence of systematic procedures for the identification, evaluation, and treatment of PE patients. Current "off-label" pharmacotherapeutic approaches include topical anesthetics, phosphodiesterase-5 inhibitors, and serotonin reuptake inhibitors. Of these, the serotonin reuptake inhibitors show the greatest efficacy and an increasing body of evidence is illuminating their mode of action. Nevertheless, all current "off-label" pharmacotherapeutic approaches fall short of the ideal therapy for PE. In the absence of a cure, such a treatment should be tolerable, inconspicuously used, effective from first dose, rapid in onset of action, and available as a prn-dosing regimen. It is anticipated that agents in development for the specific indication of PE will come closer to this ideal than existing pharmacotherapeutic approaches.

Effects of chronic selective serotonin reuptake inhibitors on 8-OH-DPAT-induced facilitation of ejaculation in rats: comparison of fluvoxamine and paroxetine

RATIONALE

Chronic treatment with selective serotonin reuptake inhibitors (SSRIs) can delay ejaculation in humans, but the extent of this effect differs between SSRIs. The involvement of 5-HT1A receptors is likely, since 5-HT1A receptor agonists accelerate ejaculation and chronic SSRI treatment is thought to desensitize 5-HT1A receptors.

OBJECTIVES

This study was conducted to examine the effects of chronic pretreatment with the SSRIs fluvoxamine and paroxetine on the facilitation of ejaculation induced by the 5-HT1A receptor agonist 8-OH-DPAT.

METHODS

Sexually experienced Wistar rats with normal ejaculatory behavior were treated for 22 days with vehicle, fluvoxamine (30 mg/kg/day), or paroxetine (10 or 20 mg/kg/day, p.o.). On day 22, rats received a challenge with saline or 8-OH-DPAT (0.4 mg/kg, s.c.). Sexual behavior was tested on days 1, 8, 15, and 22 of the SSRI-treatment.

RESULTS

Treatment with both doses of paroxetine, but not fluvoxamine, delayed ejaculation. 8-OH-DPAT strongly accelerated ejaculation under vehicle conditions. Pretreatment with paroxetine reduced the effects of 8-OH-DPAT on ejaculation in a dose-dependent manner and more strongly than fluvoxamine.

CONCLUSIONS

SSRIs affect 5-HT1A receptors involved in ejaculation. The degree to which this occurs, with paroxetine exerting a stronger effect than fluvoxamine, might determine the extent of SSRI-induced delayed ejaculation.

Neurochemical, pharmacokinetic, and behavioral effects of the novel selective serotonin reuptake inhibitor BMS-505130

BMS-505130 is a potent and selective serotonin transport inhibitor; K(i) for binding to the serotonin transporter = 0.18 nM (K(i) values for binding to the norepinephrine and dopamine transporters = 4.6 and 2.1 microM, respectively). In platelet serotonin uptake studies BMS-505130 (5 mg/kg, p.o.) produced a robust inhibition of serotonin uptake. In microdialysis studies oral dosing with BMS-505130 produced a dose-dependent increase in cortical serotonin levels that reached a maximal effect of 200% above baseline at a dose of 1 mg/kg, p.o.; the peak serotonin response was transient in nature. Following oral administration, peak plasma concentrations of BMS-505130 reached Tmax at 1.6 +/- 0.7 h and then declined to concentrations <10% of Cmax within the following 6 h; plasma half-life following i.v. dosing was 0.46 +/- 0.02 h. Parallel microdialysis and pharmacokinetic studies revealed that changes in serotonin levels in the cortex mirrored changes in the brain concentration of BMS-505130. In a behavioral assay known to be sensitive to selective serotonin reuptake inhibitors (SSRIs), mouse tail suspension, BMS-505130 produced a robust response after either oral or intraperitoneal dosing. BMS-505130 exhibits a pharmacological, neurochemical and behavioral profile consistent with a potent SSRI. Moreover, BMS-505130's short half-life may be advantageous for the treatment of premature ejaculation where an acute effect to delay ejaculation followed by a relatively rapid fall in SSRI plasma concentrations might be desirable.

Citalopram combined with WAY 100635 inhibits ejaculation and ejaculation-related Fos immunoreactivity

The role of 5-HT (5-hydroxytryptamine, 5-HT)(1A) receptor activation in the sexual side-effects, in particular delayed ejaculation, of selective serotonin reuptake inhibitors (SSRIs) was studied. Male Wistar rats were treated for 15 days with vehicle, the SSRI citalopram (10 mg/kg/day p.o.), the 5-HT(1A) receptor antagonist N-[2-[4-(2-methoxyphenyl)-1-piperazinyl] ethyl]-N-(2-pyridinyl) cyclohexane carboxamide 3HCL (WAY 100635, 0.1 mg/kg/ day s.c.), or both drugs combined. Sexual behavior was assessed weekly. One h after the last sexual behavior test, rat brains were processed for Fos-immunohistochemistry. Acute and chronic citalopram mildly inhibited ejaculation, which was strongly augmented by co-administration of WAY 100635. WAY 100635 alone did not alter sexual behavior. Brain sites associated with ejaculation showed reduced Fos-immunoreactivity in rats treated with both citalopram and WAY 100635. Citalopram reduced Fos-immunoreactivity in the arcuate hypothalamic nucleus, an area that might link serotonergic neurotransmission to ejaculation.

Venlafaxine extended release for the treatment of patients with premature ejaculation: a pilot, single-blind, placebo-controlled, fixed-dose crossover study on short-term administration of an antidepressant drug

In this study, we aimed at evaluating the efficacy and safety of venlafaxine extended release 75 mg, a serotonin and noradrenaline reuptake inhibitor, in the treatment of patients with premature ejaculation. Thirty-one patients with intravaginal ejaculation latency of less than 2 min received venlafaxine XR (75 mg/day) or placebo during a 2-week period for each agent with a washout period of 1 week between agents. Efficacy was assessed for each agent with changes in ejaculation latency measured with a stopwatch and sexual satisfaction scores of patients and partners. Side-effects, pre- and post-treatment levels of biochemical and spermiogram parameters, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin and total testosterone were recorded for each agent. Statistical analysis was performed on 21 patients. After 2 weeks of treatment with placebo and venlafaxine, ejaculation latency time was significantly increased from 60.1 +/- 39.1 to 126.9 +/- 98.3 sec and to 178.1 +/- 122.8 sec, respectively (p < 0.0001 for each one). However, the difference between the two agents was insignificant (p = 0.144). Venlafaxine and placebo increased sexual satisfaction scores of both patients and partners similarly, no statistically significant difference was found between them in this respect. The incidence of side-effects with venlafaxine was indifferent than that of placebo (p > 0.1) except nausea (p = 0.035). Both agents did not change the blood and spermiogram parameters significantly, except FSH increases. Short-term use of venlafaxine XR 75 mg has only a placebo effect on ejaculation latency and sexual satisfaction scores, therefore, is not appropriate for the patients with premature ejaculation. Further dose-time studies are required to draw final conclusions on the inefficacy of this drug in premature ejaculation.

Relevance of an evidence-based ejaculation time cutoff point for neurobiological research of premature ejaculation

The Diagnostic and Statistical Manual (DSM)-IV definition of premature ejaculation is not based on evidence-based studies. In particular, the absence of a well-defined quantitative measure of the intravaginal ejaculation latency time (IELT) makes the DSM definition inadequate. Therefore, the DSM-IV definition should be replaced by a medical definition that incorporates both quantitative as qualitative parameters of premature ejaculation. An evidence-based medical definition should include a cutoff point of the IELT at the 0.5 and 2.5 percentiles of the IELT distribution in the general male population. Such a definition has recently been proposed on the basis of a stopwatch study of the IELT in 491 men from five different countries. Similarly, a cutoff point of ejaculation frequency in laboratory rats enhances the probability to distinguish genuine rapid-ejaculator rats. Only by the strict application of these cutoff points is the probability enhanced that human and animal neurobiological research can prove whether these sexual endophenotypes differ in brain activation, have particular genetic genotypes (polymorphisms), are strictly under genetic control, or are dependent on environmental conditions and/or genotypic/environmental interactions.

On-demand SSRI treatment of premature ejaculation: pharmacodynamic limitations for relevant ejaculation delay and consequent solutions

INTRODUCTION

Recently, the idea has emerged that on-demand use of serotonin reuptake inhibitors (SSRIs), particularly short half-life, should be equally effective in delaying ejaculation as daily SSRI treatment of premature ejaculation.

AIM

To provide evidence that SSRI-induced ejaculation delay is mainly dependent on pharmacodynamic properties of the drug and hardly on pharmacokinetic factors, and that combined SSRI administration with specific 5-hydroxytryptamine (5-HT) receptor antagonism leads acutely to stronger ejaculation delay than acute SSRI monoadministration.

METHODS

We performed a detailed analysis of serotonin neurotransmission and reviewed animal studies with 5-HT(1A) receptor antagonists. In addition, we critically reviewed existing on-demand SSRI treatments publications and the current debate on a definition of premature ejaculation.

MAIN OUTCOME MEASURES

Intravaginal ejaculation latency time (IELT).

RESULTS

Acute SSRI administration leads to only a mild or no increase of 5-HT neurotransmission and concomitant stimulation of postsynaptic 5-HT receptors. Existing on-demand SSRI treatment studies suffer from methodological insufficiencies, and the reported high-fold increases of ejaculation time contradict with neuropharmacological insights from serotonin metabolism. Animal studies show that SSRI coadministration with 5-HT(1A) receptor antagonists significantly increases the ejaculation time acutely compared to acute SSRI monoadministration.

CONCLUSION

On-demand SSRI treatment has less ejaculation-delaying effects than daily SSRI treatment. SSRIs with a short half-life are likely leading to much less ejaculation delay than current registered SSRIs. Combined use of SSRIs with 5-HT(1A) receptor antagonists increases the likelihood of clinically relevant ejaculation delay after on-demand treatment. On-demand SSRIs with short half-life that insufficiently delay ejaculation in men with IELTs less than 1 minute should be called ejaculation-delaying drugs rather than drugs against premature ejaculation.

Dopamine and serotonin: influences on male sexual behavior

Steroid hormones regulate sexual behavior primarily by slow, genomically mediated effects. These effects are realized, in part, by enhancing the processing of relevant sensory stimuli, altering the synthesis, release, and/or receptors for neurotransmitters in integrative areas, and increasing the responsiveness of appropriate motor outputs. Dopamine has facilitative effects on sexual motivation, copulatory proficiency, and genital reflexes. Dopamine in the nigrostriatal tract influences motor activity; in the mesolimbic tract it activates numerous motivated behaviors, including copulation; in the medial preoptic area (MPOA) it controls genital reflexes, copulatory patterns, and specifically sexual motivation. Testosterone increases nitric oxide synthase in the MPOA; nitric oxide increases basal and female-stimulated dopamine release, which in turn facilitates copulation and genital reflexes. Serotonin (5-HT) is primarily inhibitory, although stimulation of 5-HT(2C) receptors increases erections and inhibits ejaculation, whereas stimulation of 5-HT(1A) receptors has the opposite effects: facilitation of ejaculation and, in some circumstances, inhibition of erection. 5-HT is released in the anterior lateral hypothalamus at the time of ejaculation. Microinjections of selective serotonin reuptake inhibitors there delay the onset of copulation and delay ejaculation after copulation begins. One means for this inhibition is a decrease in dopamine release in the mesolimbic tract.

On-Demand Treatment of Premature Ejaculation with Clomipramine and Paroxetine: A Randomized, Double-Blind Fixed-Dose Study with Stopwatch Assessment

OBJECTIVE

To investigate the degree of ejaculation delay induced by on-demand treatment with 20 mg paroxetine and 25 mg clomipramine and to assess the type and severity of non-sexual side-effects of treatment at the day of and the day after treatment with these drugs.

METHOD

A randomized, double-blind, fixed-dose, on-demand study in 30 men with lifelong premature ejaculation was performed. During a 1-month baseline period and a 4-week drug treatment period patients assessed the intravaginal ejaculation latency time (IELT) at home with a stopwatch. Only men with an IELT <1 min were randomly assigned to drug treatment. Patients assessed the drug coitus interval time (DCIT) and used the UKU side effect scale questionnaire at baseline, the day of and the day after intercourse.

RESULTS

On-demand treatment with 25 mg clomipramine, with a mean DCIT of 5.14 h, led to a 4.05 (95%CI: 3.26-5.02) fold-increase of the IELT. On-demand treatment with 20 mg paroxetine, with a mean DCIT of 5.39 h, led to a 1.41 (95%CI: 1.22-1.63) fold-increase of the IELT. Both drugs had a high incidence of non-sexual side effects at the coitus day and the next day. At the day of coitus paroxetine led to significant sleepiness and yawning compared to clomipramine. At the day after coitus clomipramine induced significant nausea compared to paroxetine.

CONCLUSION

On-demand treatment with 25 mg clomipramine led to a clinical relevant ejaculation delay. In contrast, 20 mg paroxetine had no clinical relevant ejaculation delay in men with lifelong premature ejaculation with an IELT of less than 1 minute. Both drugs exert mostly mild yet annoying non-sexual side effects both at the coitus day and the next day.

Topical anaesthetic use for treating premature ejaculation: a double-blind, randomized, placebo-controlled study

OBJECTIVE

To assess the use of a topical anaesthetic mixture to improve premature ejaculation (PE), for which penile hypersensitivity might be a cause.

PATIENTS AND METHODS

The study included 42 men divided in two groups; group A used a lidocaine-prilocaine solution and group B used an inert cream. The tubes of cream were distributed randomly and participants asked to note any unpleasant symptoms, difficulties and the results of each attempt at intercourse, assessed by the intravaginal ejaculatory latency time (IELT).

RESULTS

There was a significant increase in the mean (sd) IELT, from 1.49 (0.9) to 8.45 (0.9) min (P < 0.001) in group A but not in group B, at 1.67 (0.7) to 1.95 (0.12) min (P > 0.05).

CONCLUSION

We suggest that anaesthetic cream might be effective for treating PE.

In vivo rat model to measure hypogastric nerve stimulation-induced seminal vesicle and vasal pressure responses simultaneously

This study presents a modified in vivo model in which the intraluminal pressures of the seminal vesicle and vas deferens can be measured simultaneously. Male Sprague-Dawley rats were grouped based on agent administered: serotonin, clomipramine, fluoxetine, sertraline, paroxetine, prazosin, terazosin, and tamsulosin. The control responses to hypogastric nerve stimulation (HNS) were recorded in each animal, and HNS was repeated after each drug administration. Serotonergic agents resulted in concentration-dependent inhibition of the HNS-induced seminal vesicle pressure increases (clomipramine>serotonin>fluoxetine>sertraline approximately paroxetine). On the other hand, only serotonin and clomipramine significantly inhibited vasal pressure responses. alpha-Adrenergic blockers inhibited both intraluminal pressure responses in a concentration-dependent manner. This model illustrates the importance of the hypogastric nerve for the stimulation of the seminal tract, with attention focused on the seminal vesicle. This model may be useful for the evaluation of drugs for the treatment of premature ejaculation.

Relevance of methodological design for the interpretation of efficacy of drug treatment of premature ejaculation: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis is to evaluate whether the design and methodology of drug-treatment studies of premature ejaculation affect the efficacy outcome differently. Therefore, methodological, design and efficacy data from 79 studies (3034 males), published between 1943 and 2003, are reviewed. A meta-analysis is performed on 43 selective serotonin reuptake inhibitors (SSRIs) and clomipramine studies (1514 males), published between 1973 and 2003; these studies were pooled to provide a summary variance-weighted effect size. The antidepressant-induced percentage increase of the intravaginal ejaculation latency time (IELT) was calculated and examined against various methodological items. A significant difference in efficacy between SSRIs was observed. Using daily treatment, paroxetine appeared more effective than the other SSRIs. Retrospective use of a questionnaire, subjective reports, single-blind and open study designs generate far greater variability of ejaculation time both at baseline and during active drug treatment than real time assessment by stopwatch. In conclusion, at daily treatment, the overall efficacy of paroxetine, clomipramine, sertraline and fluoxetine is comparable, but paroxetine exerts the strongest ejaculation delay. Only eight (18.5%) studies on antidepressant treatment fulfilled all criteria used in evidence-based medicine, for example, randomised, double-blind studies with prospective real time (stopwatch) assessment of the IELT at each intercourse. Single-blind studies, open designs, retrospective reporting, or the use of a questionnaire to assess ejaculation time should be avoided.

Extensive Neurophisyological Evaluation in Primary Premature Ejaculation Patients

Pudendal nerve somatosensory evoked potentials (PN-SEPs), bulbo-cavernosus reflex (BC reflex) and perineal motor evoked potentials (BC MEPs) following transcranial magnetic cortical stimulation (TMS) were performed in patients with primary premature ejaculation (PPE), to investigate the somatic sensory and motor function of the genital area.

Methods

Fourteen patients with PPE underwent psychological counseling, urologic physical and trasnrectal ultrasound examination, laboratory data and Stamey test. Spinal and cortical PN-SEPs were recorded by dorsal nerve stimulaiton at penile shaft (DN-SEPs) in all patients, and at glans penis (GP-SEPs) in 3 of them. BC reflex was obtained by stimulating the basis of penis.

Results

Mean sensory thresold did not significantly differ between patients and normal subjects. Cortical DN-SEPs were normal in alla patients. Sensory central conduction was significantly smaller in patients than controls. In 3 patients and in 3 controls undergone both DN-SEPs and GP-SEPs, glans penis sensory threshold was lower than dorsal nerve one, and cortical GP-SEP latency longer than cortical DN-SEP latency. BC reflex was normal in most patients. BC MEPs were normal in all patients, but one.

Conclusions

We did not confirm either a faster conduction along the pudendal sensory pathway, or a greater cortical representation of the sensory stimuli from the genital area in oue patients. Moreover, we did not confirm an hyperexcitability of BC reflex in them. Our results suggest that the electrophysiological approach is probably not sufficient to clariphy the causes of PPE and more integrated investigation are requested.

Lifelong premature ejaculation: from authority-based to evidence-based medicine

Historically, four periods can be distinguished in the approach to and treatment of lifelong premature ejaculation. Although drug treatment has been an option for many decades, psychotherapy prevailed as the first choice of treatment. However, the application of the principles of evidence-based medicine shows that there is little evidence to support the psychological approach and behavioural treatment. In contrast, controlled trials with selective serotonin reuptake inhibitors, clomipramine and anaesthetic ointments have repeatedly shown the efficacy of both daily and 'as-needed' drug treatment to delay ejaculation. Currently, an evidence-based approach is gradually replacing the authority-based psychological attitude that characterized the view of premature ejaculation. Based on psychopharmacological studies there is evidence that premature ejaculation is related to a diminished serotonergic neurotransmission, and 5-HT2C or 5-HT1A receptor disturbances. Moreover, animal studies show the presence of a distinct ejaculation-related neural circuit in the central nervous system; its role in premature ejaculation remains to be elucidated.

Antidepressants and ejaculation: a double-blind, randomized, fixed-dose study with mirtazapine and paroxetine

A double-blind, fixed-dose study in healthy men with lifelong early ejaculation was performed to evaluate potential differences in their effects on ejaculation latency, between clinically relevant doses of the selective serotonin reuptake inhibitor paroxetine and the noradrenergic and specific serotonergic antidepressant mirtazapine. Twenty-four men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to paroxetine (20 mg/d) or mirtazapine (30 mg/d) for a period of 6 weeks; half the dosage was given in the first week. During the preceding 1-month baseline and 6-week treatment period, intravaginal ejaculation latency times were measured at home using a stopwatch procedure. The trial was completed by 18 men. Analysis of variance revealed a between-group difference in the development of the delay in intravaginal ejaculation latency time over time (P < 0.001); the intravaginal ejaculation latency time after paroxetine and mirtazapine gradually increased from 15 to 119 s and from 23 to 28 s, respectively, after 6 weeks. Paroxetine 20 mg/d exerted a strong delay (maximum 5.7-fold increase), whereas mirtazapine 30 mg/d did not delay ejaculation (0.9-fold increase). These results confirm earlier findings that paroxetine, but not mirtazapine, significantly delays orgasm and ejaculation in men with early ejaculation, whereas mirtazapine is devoid of any effect on it.

Differential pharmacological treatment of paraphilias and sex offenders

This article gives an overview of current pharmacological treatment of paraphilias and sex offenders focusing on the situation in Germany. Information about selective serotonin reuptake inhibitors (SSRI) is followed by data about established antihormonal substances (cyproterone acetate/CPA, and medroxyprogesterone acetate/MPA), as well as a more detailed account on luteinizing hormone-releasing hormone agonists (LHRH agonists). The results of open, uncontrolled clinical studies with SSRIs (n = 16) and LHRH agonists (n = 11) in paraphilic outpatients confirm the positive effects of these substances. A survey about the use of CPA and LHRH agonists in forensic hospitals in Germany shows that half of the patients treated with any kind of (anti-) hormonal agents received an LHRH agonist. The authors present a protocol on side effects, contraindications, and monitoring of CPA and LHRH agonists and develop an algorithm for differential pharmacotherapy of paraphilias.

Neurophysiologic evaluation of central-peripheral sensory and motor pudendal pathways in primary premature ejaculation

OBJECTIVES

Pudendal nerve somatosensory evoked potentials (SEPs), the bulbocavernosus (BC) reflex, and BC perineal motor evoked potentials after transcranial magnetic cortical stimulation were performed in patients with primary premature ejaculation to investigate the somatic sensory and motor function of the genital area.

METHODS

Fourteen patients with primary premature ejaculation underwent psychological counseling, urologic physical examination, transrectal ultrasound examination, laboratory testing, and the Stamey test. The spinal and cortical pudendal nerve SEPs were performed by dorsal nerve stimulation at the penile shaft (DN-SEPs) in all patients and at the glans penis (GP-SEPs) in 3 of them. The BC reflex was obtained by stimulating the base of the penis.

RESULTS

The mean sensory threshold did not significantly differ between the patients and normal subjects. Cortical DN-SEPs were normal in all patients. The sensory central conduction time, calculated in 6 patients, was normal. The mean cortical DN-SEP amplitude was significantly smaller in patients than in controls. In 3 patients and in 3 controls who underwent both DN-SEP and GP-SEP testing, the glans penis sensory threshold was lower than the dorsal nerve threshold and the cortical GP-SEP latency was longer than the cortical DN-SEP latency. The BC reflex was normal in most patients. The BC motor evoked potentials were normal in all patients, but one.

CONCLUSIONS

We did not confirm either a faster conduction along the pudendal sensory pathway or a greater cortical representation of the sensory stimuli from the genital area in our patients. Moreover, we did not confirm hyperexcitability of the BC reflex in them. Our results suggest that the electrophysiologic approach is probably not sufficient to clarify the causes of primary premature ejaculation. A more integrated investigation could allow better results in this field.

Effects of various nitric oxide-donating drugs on adrenergic tension of human seminal vesicles in vitro

OBJECTIVES

To evaluate the effects of the nitric oxide (NO)-donating compounds sodium nitroprusside (SNP), S-nitroso-glutathione (GSNO), S-nitroso-N-acetylcysteine (SNAC), S-nitroso-N-acetylcysteine-ethylester (SNACET), and linsidomine (SIN-1) on the adrenergic tension of isolated human seminal vesicle strip preparations. The significance of the NO-cyclic guanosine monophosphate (cGMP) pathway in the regulation of smooth muscle tone in the human genitourinary tract has been well established. However, information on the significance of NO-mediated signal transduction in the functional control of the mammalian seminal vesicles is still sparse.

METHODS

Seminal vesicle strip preparations were applied to an organ bath system under standard conditions. Tension was induced by the addition of 10 microM norepinephrine. After stable tension plateaus had been reached, the drugs were added in a cumulative manner (0.01 to 100 microM) and the isometric responses of the tissue registered. The effects of the compounds on the phasic contractility of the tissue preparations were also evaluated. The adenylyl cyclase-stimulating agent forskolin was used as a reference compound known to interfere with the cyclic adenosine monophosphate pathway.

RESULTS

Adrenergic tension was dose dependently attenuated by the drugs. The rank order of potency, from greater to lesser, was GSNO, SNAC, SNP, SIN-1, forskolin, and SNACET. The rank order (from greater to lesser) with regard to the inhibitory effects of the compounds on the frequency of phasic contractions of the tissue induced by the addition of norepinephrine was GSNO, SNAC, SNP, and SIN-1; the effects of SIN-1, forskolin, and SNACET on the frequency of contractions were nearly equipotent.

CONCLUSIONS

Our results strongly support the hypothesis that the contractility of the human seminal vesicle is under the control of the NO-cGMP pathway. This finding may give a rationale for the use of S-nitrosothiols, such as GSNO and SNAC, in the pharmacotherapy of hyperexcitatory disturbances of ejaculation (premature ejaculation).

The neurobiological approach to premature ejaculation

PURPOSE

Data showing the neurobiological background of rapid ejaculation was reviewed. In addition, new hypotheses to integrate clinical symptomatology, psychopharmacotherapy and psychotherapy of rapid ejaculation with brain function are provided.

MATERIALS AND METHODS

A computerized MEDLINE search, and manual bibliographic review of cross-references and neurobiological animal studies were performed. These reports were analyzed, summarized and compared with the studies performed by the author.

RESULTS

The literature on premature ejaculation published between 1887 and 2001 was reviewed. It appeared that the various psychological hypotheses and psychotherapies have not adequately been investigated. In contrast, psychopharmacological treatment studies, animal research data and stopwatch assessments in men with rapid (premature) ejaculation indicate that lifelong rapid ejaculation is a neurobiological phenomenon related to central serotonergic neurotransmission and likely influenced by hereditary factors.

CONCLUSIONS

Basic and clinical psychopharmacological studies suggest that premature ejaculation is a not a psychological disturbance but a neurobiological phenomenon.

Effects of various nitric oxide donating agents on the contractility and cyclic nucleotide turnover of human seminal vesicles in vitro

OBJECTIVES

To evaluate the effects of the nitric oxide (NO)-donating drugs sodium nitroprusside, S-nitroso-glutathione (GSNO), S-nitroso-N-acetylcysteineetylester (SNACET), and linsidomine (SIN-1), as well as the adenylyl cyclase-stimulating agent forskolin, on electrically induced contractions and on tissue levels of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) of isolated human seminal vesicle strip preparations. The significance of the L-arginine-NO-cGMP pathway in the regulation of smooth muscle tone in the human genitourinary tract has been well established; however, information on the relevance of NO-mediated signal transduction in the functional control of mammalian seminal vesicles is still sparse.

METHODS

Seminal vesicle strip preparations were applied to an organ bath system under standard conditions. Phasic contractions were induced by electrical field stimulation (frequency 80 Hz, amplitude 10 V, single pulse 1 ms, total pulse duration 1 second, pause 90 seconds). After stable contraction amplitudes had been reached, the drugs were added in a cumulative manner (0.001 to 10 microM), and the isometric responses were registered. After drug exposure, freezing, tissue homogenization, and extraction of cyclic nucleotides, cAMP and cGMP were measured by means of enzyme-linked immunosorbent assays.

RESULTS

Electrical field stimulation-induced amplitudes were attenuated by the drugs in a dose-dependent manner. The rank order of potency was GSNO > sodium nitroprusside > forskolin > SNACET > or = SIN-1. The relaxing effect of GSNO was antagonized in the presence of 10 microM of guanylyl cyclase inhibitor methylene blue. The inhibitory effects of GSNO, sodium nitroprusside, and forskolin on the contractile activity were paralleled by an increase in tissue cGMP (2 to 100-fold) and cAMP (7 to 9-fold).

CONCLUSIONS

Our results strongly support the hypothesis that the contractility of human seminal vesicles is in part regulated by the NO-cGMP-cascade. This may give a rationale for the use of S-nitrosothiols, such as GSNO, in the pharmacotherapy of hyperexcitatory disturbances of ejaculation.

SSRIs and ejaculation: a double-blind, randomized, fixed-dose study with paroxetine and citalopram

Selective serotonin reuptake inhibitors (SSRIs) are known to induce delayed orgasm and ejaculation. However, different SSRIs may differentially delay ejaculation. A double-blind, fixed-dose study in healthy men with lifelong rapid ejaculation was performed to evaluate potential differences between clinically relevant doses of two selective serotonin reuptake inhibitors, paroxetine and citalopram, in their effects on ejaculation. Thirty men with an intravaginal ejaculation latency time (IELT) less than 1 minute were randomly assigned to receive paroxetine (20 mg/day) and citalopram (20 mg/day) for 5 weeks, after taking half the dosage in the first week. During the 1-month baseline and 6-week treatment period, IELTs were measured at home by using a stopwatch procedure. The trial was completed by 23 men. Analysis of variance revealed a between-group difference in the evolution of IELT delay over time (p = 0.0004); the IELT after paroxetine and citalopram gradually increased from 18 and 21 seconds to approximately 170 and 44 seconds, respectively. Paroxetine 20 mg/day exerted a strong delay (8.9-fold increase), whereas citalopram 20 mg/day mildly delayed ejaculation (1.8-fold increase). These results indicate that paroxetine leads to a significant delay in orgasm and ejaculation, whereas citalopram seems to have less of an effect on it.

Antidepressants and ejaculation: a double-blind, randomized, placebo-controlled, fixed-dose study with paroxetine, sertraline, and nefazodone

Antidepressant medication is often associated with sexual side effects. A double-blind, placebo-controlled study in men with lifelong rapid ejaculation was performed to assess the effects of two selective serotonin (5-HT) reuptake inhibitors--paroxetine and sertraline--and the 5-HT2 antagonist and 5-HT/noradrenaline reuptake inhibitor nefazodone on the latency to ejaculate. Forty-eight men with an intravaginal ejaculation latency time (IELT) of a maximum of 1 minute were randomly assigned to receive paroxetine (20 mg/day), sertraline (50 mg/day), nefazodone (400 mg/day), or placebo for 6 weeks. During the 1-month baseline and 6-week treatment period, IELTs were measured at home with a stopwatch. The trial was completed by 40 men. During the 6-week treatment period, the geometric mean IELT in the placebo group was stable at approximately 20 seconds. Analysis of variance revealed a between-group difference in the evolution of IELT delay over time (p = 0.002); the IELT after paroxetine and sertraline gradually increased to approximately 146 and 58 seconds, respectively, compared with 28 seconds in the nefazodone group. The paroxetine and sertraline groups differed significantly (p < 0.001 and p = 0.024, respectively) from placebo, but the nefazodone group did not (p = 0.85). Compared with baseline, paroxetine exerted the strongest delay in ejaculation, whereas sertraline delayed it only moderately. There was no clinically relevant delay in ejaculation with nefazodone.

Ejaculatory physiology and dysfunction

The sequence of events encompassing ejaculation has been well described. Multiple disease processes can result in ejaculatory dysfunction. Evaluation and subsequent treatment of ejaculatory dysfunction is possible using behavioral, mechanical, and medical and surgical modalities. Further elucidation of ejaculation is now taking place at the molecular level.

Comparison of moclobemide with selective serotonin reuptake inhibitors (SSRIs) on sexual function in depressed adults. The Australian and German Study Groups

OBJECTIVE

To compare the emergent sexual effects of moclobemide and selective serotonin reuptake inhibitors (SSRIs) during acute and maintenance therapy in routine practice.

METHOD

268 patients were evaluated for sexual function at baseline, 6 weeks, 3 and 6 months of treatment using physician ratings and self-rating questionnaires. Patients received moclobemide, an reversible monoamine oxidase A inhibitor (RIMA), or a SSRI (fluoxetine, fluvoxamine, paroxetine, sertraline).

RESULTS

Baseline values were similar in all groups. Incidences of impairments of sexual functioning with treatment, whether clinically relevant or not, were 24.3% with moclobemide and 61.5% with SSRIs (physician ratings), with no significant tolerance to these effects. There was a suggestion of differences between the SSRIs in their specific dysfunctions they cause. SSRIs (21.6% of patients) had about ten times the moclobemide rate (1.9%) of sexual dysfunction reported as adverse events. Antidepressant efficacy was comparable between treatments.

CONCLUSION

In patients for whom sexual function is important or sexual dysfunction is present, moclobemide should be considered a first line antidepressant.

Neuroreceptor function and psychopharmacologic response

Psychiatric diagnoses are imprecise and that imprecision flows from current diagnostic criteria. Essentially psychiatric conditions are viewed, reported, and studied from a syndromal perspective. That is, if sufficient signs and symptoms are present, then a specific diagnosis can be made. This relative "softness" contrasts with more pathophysiology-based diagnostic criteria used by our medical-surgical colleagues. As psychiatry and psychiatric nursing move toward a more scientific base for diagnosis, a greater emphasis has been placed on psychobiological dimensions of illness. The most aggressive approach to treating the psychobiological "causes" of mental disorders is the psychopharmacological approach. Essentially all psychotropic drugs affect neurotransmitter systems, however it is becoming clear that effects on receptors may be the most significant aspect of drug therapy. This article reviews receptor function and specific receptors known to be important in both the pathology and treatment of mental disorders.

Pharmacological treatment of premature ejaculation

Ejaculatory dysfunction is the most common male sexual disorder and premature ejaculation the most common presentation of ejaculatory dysfunction. Convincing data are lacking from controlled clinical studies to support sustainable long term efficacy of psychosexual counselling in the management of premature ejaculation. The pharmacological treatment of premature ejaculation is now receiving increased attention from both physicians with an interest in sexual medicine and from the pharmaceutical industry.

Effect of SSRI antidepressants on ejaculation: a double-blind, randomized, placebo-controlled study with fluoxetine, fluvoxamine, paroxetine, and sertraline

Depression is a common cause of sexual dysfunction, but also antidepressant medication is often associated with sexual side effects. This article includes two related studies. The first double-blind, placebo-controlled study was conducted in men with lifelong rapid ejaculation and aimed to assess putative differences between the major selective serotonin reuptake inhibitors (SSRIs) (fluoxetine, fluvoxamine, paroxetine, and sertraline) with regard to their ejaculation-delaying effect. Sixty men with an intravaginal ejaculation latency time (IELT) of 1 minute or less were randomly assigned to receive fluoxetine 20 mg/day, fluvoxamine 100 mg/day, paroxetine 20 mg/day, sertraline 50 mg/day, or placebo for 6 weeks. During the 1-month baseline and 6-week treatment periods, the men measured their IELT at home using a stopwatch. The trial was completed by 51 men. During the 6-week treatment period, the geometric mean IELT in the placebo group was constant at approximately 20 seconds. Analysis of variance revealed a between-groups difference in the evolution of IELT delay (p = 0.0004); in the paroxetine, fluoxetine, and sertraline groups there was a gradual increase to about 110 seconds, whereas in the fluvoxamine group, IELT was increased to only approximately 40 seconds. The paroxetine, fluoxetine, and sertraline groups differed significantly (p < 0.001, p < 0.001, p = 0.017, respectively) from placebo but the fluvoxamine group did not (p = 0.38). Compared with baseline, paroxetine exerted the strongest delay in ejaculation, followed by fluoxetine and sertraline. There was no clinically relevant delay in ejaculation with fluvoxamine. In men with lifelong rapid ejaculation, paroxetine delayed ejaculation most strongly, whereas fluvoxamine delayed ejaculation the least. The second double-blind, placebo-controlled study was carried out in men with lifelong rapid ejaculation (IELT < or = 1 minute) and in men with lifelong less-rapid ejaculation (IELT > 1 minute) to investigate whether data about SSRI-induced delayed ejaculation in men with rapid ejaculation may be extrapolated to men with less-rapid ejaculation. After measurement of IELT at home (using a stopwatch) during a 1-month baseline assessment, 32 men with an IELT of 1 minute or less (group 1) or more than 1 minute (group 2) were randomly assigned to receive paroxetine 20 mg/day or placebo for 6 weeks in a double-blind manner. Patients continued to measure their IELTs at home during the 6 weeks of the study. At baseline, 24 patients consistently had IELTs of one minute or less (group 1), and eight patients had IELTs of more than 1 minute (group 2). The geometric mean IELT was 14 seconds in group 1 and 83 seconds in group 2. Twelve patients in group 1 and five in group 2 were randomized to the paroxetine 20 mg/day. The percentage increase in the geometric mean IELT compared with baseline in patients treated with paroxetine was 420% (95% confidence interval [CI], 216-758%) in group 1 and 480% (95% CI, 177-1,118%) in group 2 (p = 0.81). After 6 weeks of treatment with paroxetine, the geometric mean IELT was 92 seconds in group 1 and 602 seconds in group 2 (p < 0.001). Therefore, the paroxetine-induced percentage increase in IELT seems to be independent of the baseline IELT. This suggests that ejaculation-delaying side effects of some SSRIs investigated in men with lifelong rapid ejaculation may be generalized to men with less-rapid ejaculation.

An empirical operationalization study of DSM-IV diagnostic criteria for premature ejaculation

The DSM-IV diagnostic criteria for premature ejaculation remain to be investigated by a clinical study. A prospective study was therefore conducted to investigate the DSM-IV definition and to provide an empirical operationalization of premature ejaculation. In this study 140 men suffering from lifelong premature ejaculation were interviewed separately from their partners. Various means of assessing the intravaginal ejaculation latency time (IELT) were compared: assessment by spontaneous answer, by questionnaire, by imagining foreplay and intercourse and estimating the ejaculation time without a clock or with a clock, and by stop-watch measurement at home over a one-month period. The number of thrusts and feelings of control during foreplay and intercourse were also assessed. A total of 110 men used the stop-watch method. Ninety percent of all the subjects ejaculated within one minute of intromission, with 80% actually ejaculating within 30 seconds. The age of the men and duration of their relationship were not correlated with IELT; however, the IELT tended to be longer for couples who had a higher frequency of intercourse. There was only a moderate correlation between the various methods of assessing IELT. The results suggest that premature ejaculation could be operationally defined as an IELT < 1 min in more than 90% of episodes of sexual intercourse, independent of age and duration of relationship.