Genital and heart rate response to erotic stimulation in men with and without premature ejaculation.

This study compared genital and penile response patterns in men with and without premature ejaculation (PE) so as to identify the potential anomalous psychosomatic relationships among men with PE. Genital and heart rate response profiles of 25 men with PE were compared with those of 13 age-matched sexually functional counterparts during visual sexual stimulation presented in combination with vibrotactile penile stimulation. Although no differences were found between men with PE and controls on maximum penile circumference change, overall penile response was significantly lower in the PE group and PE men who ejaculated during the session exhibited shorter latencies to maximum circumference change. Furthermore, significant differences were found between groups in patterns of heart rate. These findings indicate differences in physiological responses between men with PE and sexually functional counterparts during erectile tumescence and progression toward ejaculation. Such differences might be explained by 'premature' sympathetic activation during the sexual response cycle in men with PE, thereby diminishing parasympathetically controlled penile response and triggering sympathetically mediated seminal emission prematurely.

The aetiology of premature ejaculation and the mind-body problem: implications for practice.

Recent attempts to find effective pharmacological treatments for premature ejaculation (PE) have spurred significant interest in the causes of, consequences of, and existing therapies for this common male sexual dysfunction. The recurring tendency in science and medicine, however, to dichotomise causes of such problems into either biological or psychological is not only counterproductive, it is misguided. Ejaculatory response should be viewed as a system of integrated and inseparable hardwired and softwired central and peripheral responses, some being readily modifiable, others not. Such a view argues that treatment of PE aimed at multiple levels of functioning will be self-enhancing and ultimately more effective in producing positive therapeutic outcomes than strategies relying solely on either psychological or biological approaches.

Predicting responsiveness to the treatment of rapid ejaculation with 25 mg clomipramine as needed.

Clomipramine (25 mg) taken as needed increases ejaculatory latency in men with rapid ejaculation (RE), although only about half the men treated respond to this regimen. It would therefore be clinically advantageous to know the patient's potential responsiveness to an 'as needed' regimen prior to treatment. The present study attempted to identify a priori factors that might enable prediction of patients' response or nonresponse to 'as needed' clomipramine. Variables relevant to rapid ejaculation were examined in 23 men with RE, 12 of whom had responded to clomipramine. Logistic regression indicated that three factors assessed prior to treatment--initial ejaculation latency, overall sexual satisfaction, and ejaculation frequency each week--significantly improved the prediction of responsiveness to this treatment regimen. Specifically, RE men with initial ejaculatory latencies over 60 s, self-reported sexual satisfaction of 5 or higher (on a seven-point scale), and ejaculation frequency of twice or more weekly were more likely to benefit from 25 mg 'as needed' clomipramine. As such, men meeting these criteria might be considered for this treatment regimen. Those not matching these characteristics might better be considered for 20 or 30 mg clomipramine given on a daily basis.

Sexual response in men with inhibited or retarded ejaculation.

Inhibited ejaculation (IE) is a poorly understood male sexual dysfunction having both somatic and psychological etiologies. This study investigated sexual response in 25 IE men with no probable somatic cause. Using a standard psychophysiological assessment procedure, these men were compared with sexually functional and other dysfunctional groups on two measures of sexual response: erectile response and self-reported sexual arousal. Within the sample of IE men, sexual response was investigated as a function of both diagnostic classification and relationship factors. Differences occurred between IE men and the other groups on erectile response and self-reported sexual arousal during psychosexual stimulation in the lab, with IE men reporting lowest levels of sexual arousal. Within the IE group, diagnostic classifications and relationship variables were also related to self-reported sexual arousal. These findings suggest that inhibited arousal may be fairly common among IE men having no apparent somatic etiology, and further that several specific relationship factors may provide potential strategies for enhancing arousal in these men.

Defining premature ejaculation for experimental and clinical investigations.

Researchers investigating premature ejaculation (PE) have employed widely diverse definitions of it, thereby limiting progress in the field. This study summarizes available research on PE, notes patterns that emerge from these studies, compares patterns across several types of studies, and suggests a common model for defining PE groups to guide future research. We surveyed two bibliographic databases, identifying 45 studies employing a definition or description of a PE group. From these, we extracted a range of information, including descriptions of the participants, recruitment procedures, if PE subtypes were identified, operational criteria for PE classification, relationship and partner information, and additional inclusion/exclusion criteria. Over 50% of studies reported no criteria, or relied on simple self-identification by participants to establish the PE group. Quantifiable behavioral criteria were used in 49% of the studies, with ejaculatory latency reported most frequently. This measure was also used as a criterion more frequently in studies focusing on assessment of sexual response, whereas the number of penile thrusts was used more frequently in studies prior to 1989. Partner information was often included but seldom used as part of the assessment procedure. Progress on research and treatment of PE will continue to be limited by the absence of commonly accepted criteria for PE group membership and by a lack of identification of relevant PE subtypes and etiologies. This paper suggests a flowchart, based on data and a rational analysis of 40 years of research, for characterizing PE in ways that could assist the development of the field.

Testing and analytical procedures for laboratory studies involving nonresponders during a limited observation period: an illustration using male sexual behavior in rats.

In many laboratory studies, a subpopulation of subjects fails to exhibit the response under investigation during the period of observation. For example, within any population of male rats, there is significant variation in the expression of sexual behavior in the presence of a receptive female. Some males may never display the full sequence of behaviors leading to ejaculation within the typical time frame of the testing session, with the resulting lack of behavioral response presenting problems in the analysis of the data. Conventional strategies range from screening such males from the study or dropping them from the analysis to constructing new variables based on estimates from existing parameters or increasing the length of the test session to capture sexual responses in a greater portion of males. Herein, we present an alternative strategy for analyzing data where outcomes are absent due to the limited observation period. Survival regression analysis enables inclusion of all subjects in the analysis whether or not they have shown the behavior of interest. Use of such a strategy not only has potential to reveal new results but also guards against bias from excluding nonresponders from the study or dropping more males from one experimental condition than another. Furthermore, this procedure can be helpful in generating the conditional probability (increase, decrease, or constant) of the response with the passage of time based on the hazard function and in estimating parameters for establishing an optimal behavioral test length for future studies.

Effective daily treatment with clomipramine in men with premature ejaculation when 25 mg (as required) is ineffective.

OBJECTIVE: To determine whether men with premature ejaculation who fail to respond to 25 mg clomipramine as needed improve when taking 10-30 mg clomipramine daily. SUBJECTS AND METHODS: Four men with premature ejaculation whose ejaculation latencies increased minimally or not at all when taking 25 mg clomipramine as needed participated in a prospective 12-week study consisting of four treatment phases, beginning with baseline (0 mg) and progressing through increasing daily doses of 10, 20, and 30 mg clomipramine. The subjects maintained daily logs of their sexual activities and estimated their ejaculatory response, sexual arousal and penile rigidity during intercourse. The subjects were contacted 8-15 weeks after the experiment to assess their satisfaction with and continued use of clomipramine. RESULTS: There was a dose-response effect on ejaculatory latency with increasing levels of clomipramine; 30 mg increased the latency from 25 s to 220 s, a clinically significant increase. In addition, 30 mg taken daily was significantly more effective than 25 mg as required. Other variables of sexual response (sexual interest, arousal and penile rigidity) were unaffected. At follow-up all four subjects expressed satisfaction and three continued the dose. CONCLUSION: Men with premature ejaculation who do not respond to clomipramine 'as required' are probably not insensitive to pharmacological treatment, but may simply require higher doses or a different regimen. All four subjects improved when taking daily clomipramine at varying doses. These results suggest that if initial treatment is unsuccessful, 20-30 mg daily clomipramine should be considered.

Ejaculatory latency and control in men with premature ejaculation: an analysis across sexual activities using multiple sources of information.

OBJECTIVE: Men with premature ejaculation (PE) exhibit diminished control over and short latency to ejaculation. The present study attempted to delineate further characteristics of men with PE and to address a number of presumed hypotheses regarding the etiology of this disorder. METHODS: Twenty-six men with PE were compared with an age-matched group of 13 sexually functional men on multiple indices of erectile and ejaculatory response during coital and masturbatory activities. These data were collected through retrospective, prospective, and laboratory methods. RESULTS: Psychophysiological testing indicated greater ejaculatory vulnerability to penile stimulation, although not visual erotic stimulation, in PE men than functional controls. PE men also showed subtle anomalies in the way they perceived their somatic response. The correlation between measures of ejaculatory latency and control was positive and high for intercourse, but low or even negative for masturbation. Whereas functional men showed consistency in ejaculatory latency over coital and masturbatory activities, PE men exhibited much shorter latencies during coitus than masturbation. Data collected under various methodologies (retrospective, prospective, and laboratory) showed greater consistency among sexually functional subjects; and preliminary analysis of laboratory data suggests psychophysiological methodology is as effective in differentiating dysfunctional from functional men as prospective and retrospective methodologies. CONCLUSION: Although ejaculatory latency and control tend to be related, these measures are not always stable over different kinds of sexual activity or using different methods of data collection. Psychophysiological methodology is effective in differentiating group membership (PE vs. control), but does not predict individual ejaculatory responses measured prospectively.

Intracavernosal self-injection therapy in men with erectile dysfunction: satisfaction and attrition in 119 patients.

This study describes a 12-24 month follow-up on 119 ED patients in an attempt to understand satisfaction with and dropout from ICI use. Results indicate 40% attrition, attributed primarily to a lack of efficacy of ICI, but also to spontaneous return of erectile function and to negative reactions surrounding the injection procedure. Multivariate analyses indicated that ICI dropouts were more likely to have co-existing premature ejaculation, low responses during psychophysiological screening, a lack of spontaneous erections prior to ICI, and an etiology that included an organogenic component. These same factors, along with low satisfaction with their sex life, were related to attrition due specifically to a lack of drug efficacy. In contrast, attrition due to recovery of spontaneous erections was associated with high sexual satisfaction. Among ongoing users, dissatisfaction was associated with higher age, shorter erections during ICI use, and low satisfaction with sex life. These findings identify a number of factors related to attrition and satisfaction, emphasizing the importance of specifying the cause for ICI attrition and, demonstrating that a substantial portion of patients who dropout do so for positive reasons.

Clomipramine in the treatment of rapid (premature) ejaculation.

Twenty-three premature ejaculators (PEs) and 11 control subjects were administered 25 mg of clomipramine in a double-blind, placebo-controlled, crossover design study. During 2-week trials, subjects took either the drug or the placebo 4 to 6 hours prior to sexual activity. Daily diary data revealed that, for both groups, orgasmic latency was significantly increased when taking the clomipramine. For the PEs, the average increase in orgasmic latency during intercourse was from less than 1 minute to more than 3.5 minutes. Subjects also participated in two laboratory sessions while on the drug and placebo. During these lab sessions they were exposed to erotic videos with and without the addition of vibrotactile stimulation to the penis. Results from the laboratory data support those from the diaries. Specifically, PEs were significantly less likely to reach orgasm during the lab sessions while on the clomipramine than while on the placebo. Further, they reported a significantly greater sense of control over their orgasm while on the drug. The results of this study, along with previous research, strongly support the value of low doses of clomipramine in the treatment of premature ejaculation, specifically when taken on an as-needed basis as little as 4 hours prior to sexual activity. It is important to note, however, that the beneficial effects of the drug were not uniform across clinical subjects. In this study, those PEs with the shortest orgasmic latencies while on the placebo were the least likely to substantially improve while on the drug. Additional research is necessary to determine whether changes in the timing and dosage of the clomipramine administration can extend the benefits of the drug to those with the shortest latencies.

Finger and penile tactile sensitivity in sexually functional and dysfunctional diabetic men.

Tactile sensitivity of the penis is related to sexual functioning, however its role in diabetic erectile problems is unclear. We evaluated penile sensitivity in 10 diabetic men with erectile dysfunction, 17 sexually functional diabetic men and 14 control subjects. Finger and penile thresholds and ratings of intensity and pleasantness for finger and penis were assessed using vibrotactile stimulation. Glycosylated haemoglobin and total and bioavailable testosterone measurements were determined and subjects completed self-reports on sexual function. Diabetic men with erectile problems had higher values of glycosylated haemoglobin than sexually functional diabetic men (p = 0.02) and both groups had lower bioavailable testosterone than control subjects (p< or =0.05). Sexually dysfunctional diabetic men had a higher finger threshold than the other two groups (p<0.01). Penile threshold for the sexually dysfunctional group was also marginally higher compared with the functional diabetic group (p<0.052) but did not differ from control subjects (p = 0.09). Diabetic men with erectile dysfunction exhibited different response patterns than sexually functional men on dimensions of intensity and pleasantness to penile stimulation. Although these data do not directly implicate subjective response to penile stimulation in diabetic erectile problems, they suggest such anomalous response could be one contributing factor.

Penile sensitivity in men: a composite of recent findings.

OBJECTIVES: To present, in standardized form, age- and dysfunction-related data from 13 studies on vibrotactile penile epiglandal thresholds in men to allow cross-study comparisons, a capability previously prevented by the use of varying methods and units of measurement. METHODS: On the basis of the summarization and standardization of multiple studies located through online searches of bibliographic data bases, penile sensory thresholds were first plotted as a function of age, and then as a function of dysfunctional or disease status. In a third plot, both age- and dysfunction-related differences were illustrated within a single plot. RESULTS: An increasing curvilinear threshold as a function of age was confirmed in the pattern derived from multiple studies. Furthermore, even when controlling for age, penile thresholds of men with erectile dysfunction lay one or more standard deviations above those of sexually functional counterparts, and this deviation became even higher during penile tumescence. When relationships among age, dysfunctional/disease status, and penile threshold were examined simultaneously, potential compounding effects of age and dysfunction emerged. CONCLUSIONS: From a research perspective, standardized information on penile vibrotactile thresholds will facilitate ongoing study aimed at elucidating the role of penile sensitivity to both erectile and ejaculatory response. From a clinical perspective, standardized information on populations of sexually functional and dysfunctional men may assist in a preliminary differential diagnosis.

A psychophysiological approach to assessing premature ejaculation.

A hierarchical psychophysiological model is described that provides a working framework for clinicians interested in addressing issues related to premature ejaculation (PE). Within this framework, psychophysiological laboratory analysis, used in conjunction with conventional self-report measures, has potential to contribute both to the measurement and understanding of premature ejaculation and to the assessment of treatment procedures aimed at alleviating PE.

8-OH-DPAT interacts with sexual experience and testosterone to affect ejaculatory response in rats.

Studies investigating the effect of 8-OH-DPAT (DPAT) on male sexual response have typically used subjects having variable sexual experience and levels of testosterone, factors known to independently influence male sexual behavior. This experiment examined the role of these two variables in the mediation of DPAT effects on sexual behavior. One hundred and six castrated males, half of whom received sexual experience, were tested with an effective dose of 8-OH-DPAT (0.1 mg/kg) or saline. In addition, males were tested under one of three regimens of testosterone. Results indicated that DPAT and testosterone exerted independent effects on ejaculatory measures, and along with sexual experience, showed interactive effects as well. When testosterone (T) levels were substantially below normal, DPAT showed no effect. When T reached threshold levels, the DPAT effect was limited to sexually experienced males. At high T levels, both experienced and naive males exhibited strong effects from DPAT. In contrast with ejaculatory measures, mounting and intromitting behaviors were relatively unaffected by DPAT. These results emphasize the importance of specifying both the animal's sexual history and its testosterone profile in studies investigating pharmacological effects on sexual response.

The treatment of premature ejaculation: psychological and biological strategies.

This review provides criteria for defining premature ejaculation (PE) and identifying men with this dysfunction. Included are discussions of possible PE subtypes and causes of PE. Furthermore, two empirically supported cognitive-behavioral approaches for treating PE are described and salient issues surrounding these types of treatment are considered. Biologically based treatments available to PE men are presented, with attention to the relative effectiveness and limitations of the various alternatives. Finally, a model illustrating factors relevant to determining the best therapeutic strategy is described, concluding with a brief discussion of the value of combining biological and psychological modes of treatment.

Bupropion and sexual function: a placebo-controlled prospective study on diabetic men with erectile dysfunction.

Many antidepressant agents interfere with sexual function. The purpose of this single-blind, prospective study was to determine sexual side effects, both positive and negative, of the amino-ketone antidepressant bupropion in a group of nondepressed diabetic men with somatic erectile dysfunction. Fourteen men participated in a 10-week protocol consisting sequentially of 2 weeks of baseline testing, 2 weeks of placebo, and 6 weeks of bupropion. Participants also completed daily and weekly questionnaires concerning sexual functioning, and a team of investigators rated various dimensions of sexual function every 2 weeks. In addition, a variety of physiologic measures, relevant either to erectile function or to neural/vascular systems that underlie sexual response, were assessed during baseline and bupropion treatment. Results indicated that neither subjective nor objective measures of erectile and overall sexual functioning worsened during bupropion. In fact, several measures suggested a trend toward improved sexual functioning. Furthermore, diabetic control was unaffected by bupropion administration. Given the lack of adverse effects on sexual function, along with the potential for improved erectile response, bupropion may provide an attractive choice for the treatment of depression in diabetic men or others for whom sexual dysfunction is a concern.

Yohimbine, erectile capacity, and sexual response in men.

In a double-blind, placebo-controlled crossover study on a group of men with erectile problems and a sexually functional comparison group, the effect of yohimbine (up to 30 mg/day) was assessed on a number of objective and subjective measures of erectile response through the use of daily logs and psychophysiological laboratory procedures involving response to visual sexual stimulation (VSS). Sexual desire, arousal, and ejaculatory response were also assessed. Results indicated no effect of yohimbine on most aspects of sexual response in sexually functional men. Mixed effects were found on measures of sexual function in men erectile dysfunction, with 3 of 11 men reporting strong positive effects. Under yohimbine, frequency of sexual activities increased, as did self-assessed genital response to VSS. Daily diaries indicated increased sexual arousal and erectile response during masturbation but not intercourse. A number of other measures, including NPT and retrospective summaries of erectile functioning at the end of drug phases, showed no effect. Results are discussed in terms of possible yohimbic effects on psychological factors that modulate overall sexual response, and consequently, erectile response.

Using a Regression Approach to Study the Influence of Male Fetuses on the Genital Morphology of Neonatal Female Rats.

Among newborn female rats considerable variability is found in genital morphology (e.g., anogenital distance, AGD). Presumably, such differences are related to prenatal androgen exposure, with greater exposure resulting in larger AGD's and thus in a trend toward masculinization. The source of prenatal androgen in female fetuses is unclear, but a role for male uterine mates has been implicated. The present study investigated the effect of a number of prenatal factors related to number and position of males in utero on female AGD in two strains of rats. Because such prenatal factors often show systematic covariance, a methodology was used that enabled statistical control over variables that could not be /experimentally controlled. Results confirmed the importance of caudal males to Female AGD,and identified two additional intra-uterine variables salient to female genital masculinization, namely the distance of the female fetus from the nearest caudal male, and the overall number of males sharing the same uterine horn. An increase in number of adjacent males was, contrary to previous reports, associated with a decrease in AGD, but this effect was limited to one strain. There was considerable variation in AGD across the two strains, and, more importantly, across litters, suggesting the importance of factors impacting the litter as a whole rather than specific individuals within the litter.