Duration Of Erection Research Articles

Effects of the serotonin receptor ligand methiothepin on reproductive behavior of the freshwater snail Biomphalaria glabrata: reduction of egg laying and induction of penile erection.

The biogenic monoamine serotonin (5-HT) has been reported to enhance egg laying in the freshwater gastropod Biomphalaria glabrata, an intermediate host for human blood flukes. Methiothepin, a vertebrate 5-HT(1/2) receptor ligand which binds with high affinity to a 5-HT receptor (5-HTlym) in Lymnaea stagnalis was tested for its ability to block egg laying in B. glabrata as a possible target for snail control. A single 30-min application of methiothepin (1 microM) was sufficient to prevent egg laying for over 1 week and did so in a dose-dependent fashion. Furthermore, single applications of methiothepin (1 microM and 10 microM) induced penile erection in a high percentage of snails tested. Latency to erection was long (at least 8 hr), but the duration of erection was long-lasting (up to 48 hr). Despite the erections, methiothepin-treated snails failed to achieve copulations. The pharmacological effect of methiothepin on both male and female reproductive processes is similar to that produced in other molluscs, and points to the gene for the 5-HT receptor mediating or modulating both or either processes as a potential target of snail control strategies. J. Exp. Zool. 289:202-207, 2001.

SILDENAFIL CITRATE (VIAGRA®) IS EFFECTIVE AND WELL TOLERATED FOR TREATING ERECTILE DYSFUNCTION OF PSYCHOGENIC OR MIXED AETIOLOGY

SUMMARYSildenafil citrate (Viagra®) has been shown to be an effective treatment for erectile dysfunction (ED) of organic aetiology. This study assessed the efficacy and tolerability of sildenafil for treating ED of psychogenic and mixed psychogenic/organic aetiology. Men with ED of psychogenic and mixed aetiology were randomised in a double‐blind, fixed‐dose study to placebo (n=95) or sildenafil 10 mg (n=90), 25 mg (n=85), or 50 mg (n=81) once daily for 28 days. Efficacy was evaluated with two global efficacy questions, a patient log of erectile activity, a sexual function questionnaire and a partner questionnaire. Patients receiving sildenafil had significantly more grade 3 (hard enough for penetration) or grade 4 (fully hard) erections per week than patients receiving placebo, and a greater proportion of patients receiving sildenafil reported that treatment had improved their erections (p<0.001). Results of the sexual function questionnaire demonstrated significant improvement for patients with ED receiving sildenafil compared with patients receiving placebo for frequency, hardness and duration of erections (p<0.01), and for enjoyment of sexual intercourse and satisfaction with sex life (p<0.05). The results of the partner questionnaire were consistent with the results reported by patients and showed that treatment with sildenafil was associated with significant improvement in the partners' own sex lives (p<0.001). Adverse events were mostly mild to moderate in nature. The commonest adverse events were headache, dyspepsia, flushing, myalgia, arthralgia and flu syndrome. Discontinuations due to treatment‐related adverse events were few, ranging from 1.1% to 6.2% for patients receiving different doses of sildenafil and 4.2% for patients receiving placebo. Sildenafil is an effective and well‐tolerated treatment for ED of psychogenic or mixed aetiology with once‐daily dosing.

ERECTILE DYSFUNCTION IN PATIENTS WITH SPINA BIFIDA IS A TREATABLE CONDITION

No AccessJournal of UrologyNeurogenic Bladder1 Sep 2000ERECTILE DYSFUNCTION IN PATIENTS WITH SPINA BIFIDA IS A TREATABLE CONDITION JEFFREY S. PALMER, WILLIAM E. KAPLAN, and CASIMIR F. FIRLIT JEFFREY S. PALMERJEFFREY S. PALMER More articles by this author , WILLIAM E. KAPLANWILLIAM E. KAPLAN More articles by this author , and CASIMIR F. FIRLITCASIMIR F. FIRLIT More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(05)67225-4AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract Purpose: Now that individuals with spina bifida live well into adulthood erectile dysfunction has become a recognized associated medical disorder. To our knowledge no study has dealt specifically with treatment of erectile dysfunction in men with spina bifida. Therefore, we conducted a prospective, blinded, randomized, placebo controlled, dose escalation, crossover study to determine the ability to treat erectile dysfunction in men with spina bifida with sildenafil citrate. Materials and Methods: Erectile dysfunction was diagnosed in 15 men 19 to 35 years old with spina bifida who were assigned to take 4 sets of tablets, 5 tablets per set, in a random order. All patients took 25 and 50 mg. sildenafil and 2 identical looking sets of corresponding placebos 1 hour before planned sexual activity. Efficacy was assessed by the effect of treatment compared to baseline, that is before treatment, on rating of erections (scored from 0 to 10), duration of erections, frequency of erections based on response to question 1 (scored from 0 to 5) of the International Index of Erectile Function and confidence to obtain an erection based on response to question 15 (scored from 1 to 5) of the International Index of Erectile Function. Results: Improved erectile function was reported while on sildenafil by 12 (80%) men compared to baseline and placebos. There was a significant dose dependent improvement of erectile function with both 25 and 50 mg. sildenafil compared to baseline (p <0.05), as mean erectile score increased by 50% and 88%, mean duration of erections increased by 192% and 266%, mean frequency of erections increased by 61% and 96%, and mean level of confidence increased by 33% and 63%, respectively. Furthermore, 50 mg. sildenafil provided greater improvement in all 4 parameters compared to 25 mg. The placebo results were not significantly different compared to baseline for any of the parameters. Conclusions: Erectile dysfunction in patients with spina bifida is a medically treatable condition. Sildenafil is effective in this patient population and improves level of sexual confidence. References 1 : The changing epidemiology of neural tube defects. United States, 1968–1989. Am J Dis Child1992; 146: 857. Google Scholar 2 : Sexuality and reproductive issues in children with myelomeningocele. Eur J Pediatr Surg1998; 8: 29. Google Scholar 3 : Oral sildenafil in the treatment of erectile dysfunction. Sildenafil study group. N Engl J Med1998; 338: 1397. Crossref, Medline, Google Scholar 4 : Impotence. NIH Consensus Development Panel on Impotence. JAMA1993; 270: 83. Crossref, Medline, Google Scholar 5 : The International Index of Erectile Function (IIEF): a multidimensional scale for assessment of erectile dysfunction. Urology1997; 49: 822. Crossref, Medline, Google Scholar 6 : Erectile dysfunction in spina bifida is treatable. Lancet1999; 354: 125. Crossref, Medline, Google Scholar 7 : Evaluation and nonsurgical management of erectile dysfunction and priapism. In: . Philadelphia: W. B. Saunders Co.1998: 1181. Google Scholar From the Division of Urology, Children’s Memorial Hospital, Northwestern University Medical School, Chicago, Illinois© 2000 by American Urological Association, Inc.FiguresReferencesRelatedDetailsCited bySnow-Lisy D, Yerkes E and Cheng E (2015) Update on Urological Management of Spina Bifida from Prenatal Diagnosis to AdulthoodJournal of Urology, VOL. 194, NO. 2, (288-296), Online publication date: 1-Aug-2015.Gatti C, Del Rossi C, Ferrari A, Casolari E, Casadio G and Scire G (2009) Predictors of Successful Sexual Partnering of Adults With Spina BifidaJournal of Urology, VOL. 182, NO. 4S, (1911-1916), Online publication date: 1-Oct-2009.WOODHOUSE C (2018) PROSPECTS FOR FERTILITY IN PATIENTS BORN WITH GENITOURINARY ANOMALIESJournal of Urology, VOL. 165, NO. 6 Part 2, (2354-2360), Online publication date: 1-Jun-2001. Volume 164Issue 3 Part 2September 2000Page: 958-961 Advertisement Copyright & Permissions© 2000 by American Urological Association, Inc.Keywordsspinal dysraphismmeningomyeloceleimpotenceMetricsAuthor Information JEFFREY S. PALMER More articles by this author WILLIAM E. KAPLAN More articles by this author CASIMIR F. FIRLIT More articles by this author Expand All Advertisement PDF downloadLoading ...

Relation of Sexual Dysfunction to Hormone Levels, Diseases and Drugs Used in Andrological Patients

In 169 patients visiting our department complaining of sexual dysfunction, the medical history was taken using a semistructured interview. A clinical investigation and a hormone analysis were added. The age of patients, hormone values, and items of the interview were collected into a common database. The items were categorized as either dichotomous (yes/no) or ordinal. Statistical analysis was performed using regression analysis with the aim to generate hypotheses of relations. An increase of FSH levels and a decrease of testosterone levels with age occurred. None of the relations of hormone levels or diseases to symptoms of sexual dysfunction produced odds ratios (OR) statistically significant different from 1. However, the risk of having a reduced libido and reduced morning erections was lower in psychoneurological diseases, the risk of reduced arousal and libido was lower in men with diabetes mellitus, but the risk of reduced morning erections was higher in these men. The testosterone levels were not associated with the risk of having reduced penile rigidity, duration of erection, arousal and sexual libido, reduced morning erections and the ability to masturbate. Smoking was not associated with reduced arousal, libido and morning erections. However, a significant increase of testosterone levels with number of cigarettes used was observed. We conclude that sexual dysfunction in patients visiting an andrological department for diagnosis and treatment is mostly not associated to any single evaluable factor.

Rigiscan versus Snap Gauge band measurements: is the extra cost justifiable?

Both RigiScan and the Snap Gauge band devices are used to objectively measure penile rigidity. The Snap Gauge band is the more simple and inexpensive of the two techniques. We investigated the correlation between the results obtained by both devices in order to evaluate whether the Snap Gauge band could be employed as the sole method of rigidity evaluation while not affecting the quality of diagnosis. Forty eight patients who were presented to our erectile dysfunction clinic used the two devices simultaneously, each according to the accepted protocols. Breakage of two and three strings of the Snap Gauge (good rigidity) correlated well with good tip and average rigidity as evaluated by the RigiScan. Snap gauge results also correlated with duration of erection, number of erections, the number of adequate erections, and the longest duration of erection measured by the RigiScan. Therefore, good rigidity according to the Snap Gauge test correlated well with the results of functional erections (number, rigidity, duration) as obtained by the RigiScan. The Snap Gauge band can be used to adequately evaluate penile rigidity. RigiScan measurements, which are more complicated and more expensive, should be reserved for selected patients in whom the results of the Snap Gauge band are inconclusive or when more detailed information is required.

Evaluation of erectile response by continuous measurement of penile diameter in rats

The present study was performed to determine whether measurement of penile diameter in an in vivo rat model is useful for pharmacologic and physiologic investigations on penile erection. Penile erection induced by electrical stimulation of the cavernous nerve was monitored by measuring the penile diameter sonomicrometrically with a pair of 10-MHz piezoelectric crystals glued to the opposite surfaces of the adventitia of the penile erectile chamber in anesthetized rats. Using this method, we examined the effects of a nitric oxide (NO) synthase inhibitor, N ω-nitro-L-arginine methyl ester (L-NAME), and a well-known phosphodiesterase 5 (PDE5) inhibitor, zaprinast, on the maximal developed penile diameter (D-max) and the time from the maximum response to 50% recovery (T50%) of the maximum response as an index of the duration of penile erection. An intravenous injection of L-NAME at a dose of 10 mg/kg significantly inhibited D-max produced by cavernous electrical stimulation at 5 to 50 V, without affecting T50%. Sequential intravenous infusions of 10, 30, 100, and 300 μg/kg/min of zaprinast at 30-min intervals did not show any effect on D-max, heart rate, and systolic arterial pressure, although doses of 100 and 300 μg/kg/min significantly prolonged T50% and the maximum dose decreased diastolic arterial pressure. Moreover, zaprinast produced a more prominent increase in cyclic guanosine monophosphate (cGMP) levels than cyclic adenosine monophosphate levels in the plasma taken at the end of the maximum dose infusion. Measurement of murine penile diameter with a sonomicrometrical device, indicating that a NO-cGMP-PDE5 pathway plays a pivotal role in the penile diameter increase and its maintenance, would be useful for pharmacologic and physiologic investigations on penile erection.

Sildenafil: a review of its use in erectile dysfunction.

Sildenafil is an oral therapy for erectile dysfunction of a broad range of causes. By selectively inhibiting phosphodiesterase type 5, it allows corpus cavernosum smooth muscle to relax, potentiating erections during sexual stimulation. Blood pressure is reduced transiently by sildenafil, but more marked hypotension may occur during concurrent administration of sildenafil and organic nitrates; this combination is contraindicated. Sildenafil is rapidly absorbed, with dose-proportional peak plasma concentrations within 1 hour of administration. The elimination half-life is 3 to 5 hours. Dosages usually begin at 50mg taken when needed =1 hour before sexual activity no more than once daily. The maximum dose is 100mg when needed once daily and lower doses (e.g. 25mg) may be used in elderly patients and those with hepatic or renal impairment or receiving cytochrome P450 enzyme CYP3A4 inhibitors, such as ritonavir, saquinavir, ketoconazole, erythromycin or cimetidine. More than 3000 patients with erectile dysfunction of organic (e.g. diabetes or spinal cord injury), psychogenic or mixed origin received sildenafil 5 to 100mg or placebo in fixed- or titrated-dose trials. Sildenafil was associated with dose-related improvements in the frequency, hardness and duration of erections and in patients' abilities to achieve and maintain erections adequate for successful sexual intercourse. In titrated-dose trials, the most commonly effective doses were 50 or 100mg, although lower doses were effective in some patients. Sildenafil was significantly more effective than placebo in erectile dysfunction of all tested causes. The efficacy of sildenafil was not affected by patient age (> or < or =65 years) or by antihypertensive or antidepressant medications. The drug was effective in patients with severe erectile dysfunction. Efficacy was maintained in long term (1-year) studies. Sildenafil also appears to improve the quality of life of both patients and their sexual partners. Common adverse events associated with sildenafil were transient and mild or moderate and included headache, flushing, dyspepsia, nasal congestion and abnormal vision. Tolerability was maintained in long term (< or =1 year) studies. No serious sildenafil-related adverse events occurred in clinical trials; cardiovascular events seen in postmarketing surveillance generally occurred in patients with other known risk factors. Sildenafil is an effective oral treatment in men with erectile dysfunction. It was significantly superior to placebo in improving erections and allowing successful penetrative sexual intercourse. Although its place in disease management is still emerging and there are contraindications to its use, if preliminary positive reports are confirmed, sildenafil will be the pre-eminent first-line therapy for erectile dysfunction.

Validity analysis of Sapporo Medical University-sexual function questionnaire

We evaluated the validity of the Sapporo Medical University-sexual function questionnaire, comparing the response to each question of patients having sexual dysfunction with those of normal volunteers as controls. Responses from 335 patients with sexual dysfunction and 490 normal volunteers aged from 20 to 39 years old were evaluated. We compared mean scores of each question for patients having sexual dysfunction with those for controls. Discriminant analysis was used for evaluating which questions contributed more strongly to discriminating patients having the disease from controls. The analysis was also used for validating the questionnaire. Mean scores for patients with sexual dysfunction were significantly lower than those for controls in all questions. Nine of the 11 questions were statistically useful to discriminate these two groups with discriminant analysis. The analysis also revealed that questions about frequency of erection, rigidity of the erectile penis and duration of erection highly contributed to discriminate these two groups. The discriminant analysis achieved high sensitivity and specificity for classifying the groups. These results suggest that the use of the Sapporo Medical University-sexual function questionnaire is valid for discriminating patients with sexual dysfunction from subjects with normal sexual function.

A Simplified Pharmacologic Erection Program for Patients with Spinal Cord Injury

Introduction and objectives: Intracavernosal injection (ICI) of vasoactive agents has been successfully used in the treatment of erectile dysfunction (ED). The authors’ pharmacologic erection program, using a fixed combination of prostaglandin El (PGE1) and papaverine, is notable for its simplicity and acceptance by patients who have suffered spinal cord injuries (SCIs).Methods: Patients undergo baseline questionnaire, physical examination, and hormone profile followed by instruction and injection of a fixed combination of PGE1 and papaverine. On successive visits, the patient injects himself and the dosage is titrated until a satisfactory erection is obtained. Patients who do not respond to injection of 1.0 cc are considered treatment failures. Patients return periodically for routine follow-up.Results: From May 1994 to March 1997, 37 patients with SCI underwent initial evaluation and 28 (76%) responded to injection therapy and were successfully using self-injection therapy at 3-month follow-up. Twenty-three patients are still on injection therapy. Five patients have dropped out for several reasons including a lack of a current sexual partner (60%) and pain with injection (40%). Patient age ranges from 24 to 72. The dosage range was 0.10 to 0.50 cc (mean = 0.29 cc). The average duration of erection was 43 minutes. At 3-month follow-up, 85% of the patients rated their erections as good or excellent. Forty-three percent of patients are using ICI 1 or more times per week. Seventy-seven percent of patients are moderately or extremely satisfied with their treatment and 89% said that they would recommend this program to a friend.Conclusions: This simplified pharmacologic erection program offers safe, well accepted, and effective therapy for ED to a SCI population with very high patient satisfaction.

The Effect of Cryosurgical Ablation of the Prostate on Erectile Dysfunction

Objective To investigate the incidence and identify the possible cause of erectile dysfunction after cryoablation of the prostate. Patients and methods Erectile function was examined prospectively in 15 sexually active men (aged 59–72 years) who underwent cryoablation of the prostate for clinically localized prostate cancer. Erectile function was assessed before and 6 months after treatment; after intracavernosal injection with 10 μg of prostaglandin E1 (PGE1), the degree and duration of erection, the size of the cavernosal arteries, the penile arterial blood flow velocity, and the time to achieve peak flow were evaluated using high-resolution ultrasonography and colour pulsed-Doppler spectral analysis. Results Post-operatively, all patients initially reported an inability to achieve an erection sufficient for vaginal intercourse. At 6 months′ follow-up, erectile dysfunction persisted in nine, with minimal or no response to the intracavernosal PGE1 injections, there was a significant decrease in the peak velocity of blood flow within cavernosal arteries and a significant increase in the time to achieve peak arterial flow. Conclusion Although many factors may contribute to erectile dysfunction after cryoablation of the prostate, vascular injury plays a major role.

Prospective Comparative Study with Intracavernous Sodium Nitroprusside and Prostaglandin E1 in Patients with Erectile Dysfunction

Purpose: To compare the effectiveness of intracavernous administration of sodium nitroprusside and prostaglandin E₁ to induce penile erection in men with erectile dysfunction. Material and Methods: 100 patients with erectile dysfunction entered the study prospectively. As part of the diagnostic workup, each patient received an intracavernous injection of 20 µg prostaglandin E₁ and a second injection of 600 µg sodium nitroprusside 1–7 days later. A tourniquet was placed at the base of the penis before each injection. The data recorded included time required to initiate tumescence, local and systemic side effects, objective and subjective quality of erections, duration of tumescence and patient satisfaction by means of a personal questionnaire. Results: Prostaglandin E₁ induced better overall responses than sodium nitroprusside, the difference being almost significant (p = 0.055). The overall duration of erections was also significantly longer with prostaglandin E₁ (mean 81.3 min) than with sodium nitroprusside (mean 65.4 min; p < 0.04). 67% of the patients considered the erections induced with prostaglandin E₁ to be of better quality than those with sodium nitroprusside, and only 11% stated that sodium nitroprusside was superior. Side effects were minimal with both drugs, the most frequent side effect being systemic hypotension, which was induced by sodium nitroprusside in 7% of the patients. Conclusions: The moderate risk of systemic hypotension and the lower potency of sodium nitroprusside to induce erections compared to prostaglandin E₁ rules out sodium nitroprusside as a routine alternative intracavernous drug in men with erectile dysfunction at the doses employed. Sodium nitroprusside, however, could be used in patients who have intolerance or penile pain with intracavernous prostaglandin E₁.

SYNTHETIC MELANOTROPIC PEPTIDE INITIATES ERECTIONS IN MEN WITH PSYCHOGENIC ERECTILE DYSFUNCTION: DOUBLE-BLIND, PLACEBO CONTROLLED CROSSOVER STUDY

Purpose We evaluated the erectogenic properties of a new cyclic alpha-melanocyte-stimulating hormone analogue, Melanotan-II, to treat men with psychogenic erectile dysfunction. Materials and Methods Ten men with erectile dysfunction of no known organic cause were entered in a double-blind, placebo controlled crossover study in which the erectogenic properties of Melanotan-II and a vehicle placebo were compared using real-time RigiScan [double dagger] monitoring. The presence, duration and rigidity of erections were recorded during a 6-hour period. Results In 8 of 10 men treated with Melanotan-II clinically apparent erections developed. Mean duration of tip rigidity greater than 80% was 38.0 minutes with Melanotan-II and 3.0 with placebo (p = 0.0045). Transient side effects of nausea, stretching and yawning and decreased appetite were reported more frequently after injections of Melanotan-II than placebo but none required treatment. Conclusions Melanotan-II is a potent initiator of erections in men with psychogenic erectile dysfunction and has manageable side effects at a dose of 0.025 mg./kg.

EFFECT OF THE SELECTIVE PHOSPHODIESTERASE TYPE 5 INHIBITOR SILDENAFIL ON ERECTILE FUNCTION IN THE ANESTHETIZED DOG

Purpose The effects of sildenafil, a highly selective inhibitor of cyclic guanosine monophosphate-specific phosphodiesterase type 5, on erectile function in the anesthetized dog were evaluated. Materials and Methods In pentobarbital-anesthetized dogs, increases in intracavernosal pressure in the corpus cavernosum and penile blood flow were induced by pelvic nerve stimulation over a frequency range of 1 to 16 hertz. The effects of increasing doses of sildenafil on electrically stimulated intracavernosal pressure, penile blood flow, blood pressure, and heart-rate were evaluated. In parallel experiments, the effects of the nitric oxide synthase inhibitor N omega-Nitro-L-Arginine (L-NOArg) on these same parameters also were assessed. Results The effects of nerve stimulation on intracavernosal pressure and blood flow to the penis were blocked by L-NOArg, 0.1-3 mg./kg., in a dose-related manner, confirming the important role of nitric oxide in producing erections. Sildenafil, 1-100 micro g./kg administered intravenously, had no direct effect on intracavernosal pressure but potentiated the increase in intracavernosal pressure induced by nerve stimulation. This potentiation occurred at sildenafil plasma concentrations consistent with its relaxation effect on isolated human cavernosal tissue and its inhibition of phosphodiesterase type 5 in vitro. Sildenafil had no significant effect on blood pressure or heart rate. Conclusions By inhibiting cyclic guanosine monophosphate-specific phosphodiesterase type 5, sildenafil augments the neuronal mechanism responsible for penile erection. This mechanism explains the significant improvements reported in the rigidity and duration of erections seen in patients with erectile dysfunction who have been treated with oral sildenafil.

Side effects of chronic intrathecal baclofen on erection and ejaculation in patients with spinal cord lesions

Objective: Assess modifications of sexual function in men treated with intrathecal baclofen for spinal spasticity. Design: Prospective before-after trial. Setting: A rehabilitation department of a university hospital; follow-up was on an outpatient basis. Patients: A convenience sample of nine consecutively recruited men with spinal cord injury or multiple sclerosis who were receiving intrathecal baclofen by an implantable pump; average follow-up was 44.4 months. Main Outcome Measures: A questionnaire focusing on: libido; ability to sustain reflexive and psychogenic erections; rigidity, evaluated by a visual analog scale; maximum duration of erection; possibility of ejaculation. Results: Libido and the ability to obtain psychogenic or reflexogenic erections were not modified. However, eight patients reported a decrease of erection rigidity and/or duration. Ejaculation was possible in three cases before implantation. It disappeared in two patients, and was more difficult to obtain in the last one. It reappeared after treatment withdrawal. No differences were found between multiple sclerosis and spinal cord injured patients. Conclusion: Intrathecal baclofen may compromise erection and ejaculation. This effect is reversible. Patients should be informed of this effect.

Correcting impotence in the male dialysis patient: Experience with testosterone replacement and vacuum tumescence therapy

Sexual dysfunction remains a common and often distressing problem in the male dialysis population. Traditionally its management has consisted of correction of anemia, optimization of dialysis, removal of implicated medication, and finally depot injections of a testosterone ester. At a dedicated renal impotence clinic, we studied the effectiveness of testosterone replacement in men with biochemically proven hypogonadism and then vacuum tumescence therapy in those with continued erectile dysfunction. Depot testosterone was given to 27 patients (aged 52.4+/-2.5 years; duration of dialysis, 2.00+/-0.40 years; and duration of sexual dysfunction, 2.92+/-0.49 years): sexual function was fully restored in only three (11.1%), and two gradually lost the response over 18 months. Nineteen patients (70.3%) had partial responses, varying from an increased sense of well-being alone to restored sexual function apart from an impairment of the duration of penile erection. Five patients (18.5%) had no response, and testosterone was contraindicated in another four. Four of the treated patients (14.8%) reported fluid retention. Vacuum tumescence devices were then offered to 32 patients who remained impotent but declined by six. Twenty-six patients (aged 49.6+/-2.2 years; duration of dialysis, 2.50+/-0.58 years; and duration of sexual dysfunction, 3.26+/-0.56 years) used the devices, with 19 (73.1%) having full correction of their erectile dysfunction; six also continued with depot testosterone to maintain their libido. Penile discomfort was described by five patients (19.2%) whose potency was not restored. A further five predialysis patients have used the devices, and all had correction of their erectile dysfunction. The correction of biochemical hypogonadism in the male dialysis population with testosterone rarely restores sexual function to normal, whereas vacuum tumescence therapy corrects penile erection dysfunction in most patients. (Am J Kidney Dis 1998 Feb;31(2):313-9)

The effect of cryosurgical ablation of the prostate on erectile function.

To investigate the incidence and identify the possible cause of erectile dysfunction after cryoablation of the prostate. Erectile function was examined prospectively in 15 sexually active men (aged 59-72 years) who underwent cryoablation of the prostate for clinically localized prostate cancer. Erectile function was assessed before and 6 months after treatment; after intracavernosal injection with 10 micrograms of prostaglandin E1 (PGE1), the degree and duration of erection, the size of the cavernosal arteries, the penile arterial blood flow velocity, and the time to achieve peak flow were evaluated using high-resolution ultrasonography and colour pulsed-Doppler spectral analysis. Post-operatively, all patients initially reported an inability to achieve an erection sufficient for vaginal intercourse. At 6 months' follow-up, erectile dysfunction persisted in nine, with minimal or no response to the intracavernosal PGE1 injections, there was a significant decrease in the peak velocity of blood flow within cavernosal arteries and a significant increase in the time to achieve peak arterial flow. Although many factors may contribute to erectile dysfunction after cryoablation of the prostate, vascular injury plays a major role.

INTRACAVERNOSAL FORSKOLIN: ROLE IN MANAGEMENT OF VASCULOGENIC IMPOTENCE RESISTANT TO STANDARD 3-AGENT PHARMACOTHERAPY

Purpose We investigated forskolin, a direct adenylate cyclase activator, as an intracavernosal vasoactive agent in management of vasculogenic impotence. Materials and Methods Concentration responses for forskolin and prostaglandin E1 induced relaxation of phenylephrine precontracted strips of human corpus cavernosum smooth muscle were constructed in vitro. Cyclic adenosine monophosphate (cAMP) synthesis was determined with papaverine, phentolamine, prostaglandin E1 and forskolin in human corpus cavernosum smooth muscle cell cultures. Dose-dependent hemodynamic responses to intracavernosal forskolin (5 to 20 micro g.) were evaluated in a New Zealand White rabbit model. Safety and efficacy outcome data were obtained in vasculogenically impotent patients who signed informed consent and met strict inclusion and exclusion criteria that included having had standard self-injection therapies fail. Results In vitro forskolin and prostaglandin E1 alone caused concentration dependent relaxation with an EC50 of approximately 200 nm. and 16 nm., respectively. When the 2 agents were combined, the concentration response curve for relaxation shifted to the left. cAMP production was highest in cells treated with prostaglandin E1 and forskolin and was unaffected by papaverine or phentolamine. In 3 animals, equilibrium intracavernosal pressure and duration of erection had a dose dependent increase. Clinical investigation in 31 patients showed no adverse events with a mean of 14 +/− 4, range 11 to 18 months of followup. Overall 61% reported improvement in rigidity and/or erection duration using intracavernosal forskolin (98 micro g./ml.), papaverine (29 mg./ml.), phentolamine (0.98 mg./ml.) and prostaglandin E1 (9.8 micro g./ml.). Conclusions Forskolin is a United States Food and Drug Administration nonapproved vasoactive agent that acts in synergism with prostaglandin E1 to induce smooth muscle relaxation. In combination with other vasoactive agents, forskolin has demonstrated preliminary safety and efficacy in patients with vasculogenic impotence resistant to standard 3-agent pharmacotherapy.

Androgen and sleep-related erections

Sleep-related penile erections provide a unique opportunity to objectively study erectile physiology in man. Testosterone is one of several factors involved in normal sexual function and testosterone reduction can be achieved by administering luteinizing-hormone releasing-hormone agonists (LHRH-A). In this study, ten healthy, young adult males were administered LHRH-A or placebo for a 12-week period. Subjects taking LHRH-A had a marginally significant decline in sleep-related erection duration at week 4 and significant reductions at weeks 8 and 12. By contrast, no statistically reliable change was found for the number of erections over the course of study. Maximum circumference increase during sleep erections showed mixed results. These results indicate that, whereas androgen reduction adversely affects sleep-related erections, it does not eliminate them over a 12-week trial in healthy young adult men. Further study in a larger sample is needed. Nonetheless, these preliminary findings support androgen having an important role in sleep-related erections.

Natural erection induced by prostaglandin-E1 in the diagnosis and treatment of congenital penile anomalies.

To report the use of a natural erection induced by prostaglandin EI (PGE1) in the diagnosis and therapy of congenital penile anomalies as an alternative to artificial erection. From February 1991 to December 1995 a natural erection was induced in 672 patients (mean age 5.7 years, range 12 months-47 years) to diagnose and treat congenital anomalies, e.g. simple penile curvature, chordee with and without hypospadias, epispadias, micropenis, cripple penis, etc. The dose injected intracavernosally was dependent on the patient's age, penile size and response, and ranged from 0.5 to 15 micrograms. A natural dilatation of erectile tissue was achieved in all forms of penile anomalies except in seven patients who did not respond. The mean duration of erection was 80 min, but a prolonged erection, for up to 6 h, occurred in two patients. The natural erection achieved by injecting PGE1 into the corpora cavernosa is a useful alternative to artificial erection in the diagnosis and treatment of congenital penile anomalies.

Papaverine-Phentolamine and Prostaglandin E1 Versus Papaverine-Phentolamine Alone For Intracorporeal Injection Therapy: A Clinical Double-Blind Study

Purpose A study was designed to compare intracorporeal injections of papaverine plus phentolamine (2-drug solution) and papaverine plus phentolamine and prostaglandin E1 (3-drug solution) for the treatment for impotence. Materials and Methods A total of 20 impotent patients received intracorporeal injections of the 2-drug or 3-drug solution alternately during 2 sessions, and the quality and duration of erections were assessed. Results Of the patients 73 percent achieved a full erection with the 3-drug solution compared to 28 percent with the 2-drug solution. The average duration of erections was 57 minutes and 33.6 minutes, respectively. The complication rate was similar for the 2 treatments. Conclusions Papaverine plus phentolamine and prostaglandin E1 is superior to papaverine plus phentolamine alone for the treatment of impotence.