Pharmacological erection: diagnosis and treatment applications in 69 patients

Pharmacologic treatment strategies for sexual dysfunction in patients with epilepsy and depression

Sexual dysfunction is a frequently encountered comorbid condition in patients with many medical and psychiatric conditions, such as epilepsy and depression. Most depressed patients experience some type of sexual dysfunction, decreased sexual desire being the most common. The association of sexual dysfunction with epilepsy is less clear. Changes in sex hormone levels are common in patients with epilepsy and may be attributable to the disease or to antiepileptic drugs (AEDs). Sexual dysfunction associated with depression or epilepsy is generally treated according to standard guidelines for the management of sexual disorders, since data from special populations are not available. The most common forms of female sexual dysfunction are lack of sexual desire and difficulty achieving orgasm. There are no approved pharmacotherapies for female hypoactive sexual desire disorder or female orgasmic disorder. Female sexual arousal disorder is treated with estrogen replacement therapy when indicated or vaginal lubricants. The most common male sexual dysfunction disorders are premature ejaculation and erectile dysfunction. Phosphodiesterase type-5 inhibitor drugs are now the first-line treatment for erectile dysfunction, and selective serotonin reuptake inhibitors and topical anesthetic creams are nonapproved but effective treatments for premature ejaculation. Testosterone and aromatase inhibitors have been used investigationally to treat sexual dysfunction in men taking AEDs. Patient education and follow-up appointments are essential to ensure optimal outcomes of pharmacologic treatments for sexual dysfunction.

The incidence and management of priapism in Western Australia: a 16 year audit

The objective of the study was to conduct a retrospective audit of patients who presented with priapism in Western Australia during the years 1985-2000. We searched the records of the teaching hospitals in metropolitan Perth and those of the Keogh Institute for Medical Research for the diagnostic code for priapism. A total of 82 episodes of priapism in 63 patients occurred over this 16 year period. In all, 62 episodes occurred after intracavernosal injections (ICI) and 20 were due to other causes. Treatment of priapism included simple aspiration of blood, intracavernosal injection of alpha-adrenergic agents and surgical shunt procedures. Priapism occurring outside the setting of ICI was more likely to require surgery; seven of 20 episodes. After ICI therapy, eight of 62 episodes required shunts. The use of prostaglandin E1 as the drug of choice in ICI therapy in 1989 led to a fall in the incidence of ICI-induced priapism. Priapism is a major side effect of ICI therapy and an uncommon, although important, side effect of other conditions. The incidence of priapism has fallen with the introduction of prostaglandin E1 monotherapy as the favoured drug for ICI therapy of erectile failure.

Liposome encapsulated prostaglandin E1 in erectile dysfunction: correlation between in vitro delivery through foreskin and efficacy in patients

OBJECTIVES

To test the delivery of prostaglandin E1 (PGE1) in novel transdermal liposomal formulations through foreskin and to determine whether there is a correlation between in vitro transdermal absorption and in vivo efficacy in patients with erectile dysfunction.

METHODS

The in vitro transdermal absorption of PGE1 through excised foreskin from liposomal formulations was tested in diffusion cells using radiolabeled drug. The in vivo studies were carried out on 5 patients (aged 54 to 70 years) in a double-blind, placebo-controlled fashion. The patients were treated topically on the penis with three different active formulations containing 0.05% PGE1 and a placebo at least 1 week apart. The change in systolic peak flow velocities in the cavernosal arteries after treatment was monitored by duplex color Doppler ultrasonography with spectral analysis every 15 minutes for 1 hour.

RESULTS

The permeability coefficient (Kp) of PGE1 from the three liposomal formulations tested was found to be 0. 10, 1.66, and 3.82 x 10(-4) cm/hr, respectively. Peak systolic flow velocities in the deep cavernosal arteries of patients increased significantly compared with preapplication values (0.05 < P < or = 0.1) after application of two of the transdermal liposomal PGE1 formulations tested (the two with the highest Kp). The highest mean peak systolic flow velocity was achieved at 45 minutes after application of the formulations. The most effective formulation in this study resulted in a sevenfold increase in mean flow velocity compared with baseline values.

CONCLUSIONS

Topical application of PGE1 in a novel transdermal liposomal delivery system can enhance penetration of the drug into the deep cavernosal bodies and increase peak systolic flow velocities in patients with erectile dysfunction. The transdermal flux and permeability of PGE1 measured in vitro correlate well with the color Doppler ultrasound results in patients. The efficacy of a formulation in the development process may be predicted from in vitro absorption studies.

Atropine role in the pharmacological erection test: study of 228 patients

PURPOSE

We determined the efficacy of atropine sulfate combined with papaverine hydrochloride, prostaglandin E1 and phentolamine mesylate in the pharmacological erection test.

MATERIALS AND METHODS

A total of 230 consecutive patients with erectile dysfunction was randomized for pharmacological erection test and received an intracorporeal combination of 50 mg. papaverine hydrochloride, 10 micrograms. prostaglandin E1, 0.2 mg. phentolamine mesylate and 0.075 mg. of atropine sulfate (group 1), or the same combination without atropine sulfate (group 2). Erectile response was evaluated subjectively and by intracorporeal pressure measurement.

RESULTS

In group 1, 40 patients (35.1%) showed only tumescence, and 22 (19.3%) had poor erection. In group 2, 45 patients (39.5%) had tumescence and 17 (14.9%) poor erection. In both groups 52 patients (45.6%) had rigid erection. There was no statistically significant difference regarding erectile response and intracorporeal pressure.

CONCLUSIONS

The addition of atropine sulfate did not improve results of the pharmacological erection test when combined with 50 mg. papverine hydrochloride, 10 micrograms, prostaglandin E1, and 0.2 mg. phentolamine mesylate.

Intracavernous pharmacotherapy

Intracavernous application of vasoactive substances not only has enhanced our understanding of penile hemodynamics, the physiology of penile erection, and the pathophysiology of erectile dysfunction but also has revolutionized the diagnosis and treatment of erectile dysfunction in the last 15 years. Virag was the first to report on the erectile effect of papaverine in humans, and Brindley later reported the effect of intracavernous application of alpha-receptor-blocking agents on cavernous tissue. These reports led to numerous basic and clinical investigations and ultimately established a new treatment alternative for patients with erectile dysfunction that is now considered to be the treatment of choice for most patients. Changes in penile hemodynamics include the relaxation of cavernous smooth musculature and arteries, which leads to an increase in arterial blood flow and a restriction of venous outflow through a compression of subtunical veins. These hemodynamic changes are the prerequisite for the induction and maintenance of penile erection. With the intracavernous application of vasoactive substances it was possible to influence penile hemodynamics at a local level and to induce an erection despite alterations in the nervous system, penile arterial blood flow, cavernous musculature, or neurotransmitter status. In addition, the local application of pharmacologically active substances directly to the end organ enabled the achievement of high local drug concentrations without severe systemic side effects. The commonly used substances are papaverine the combination of papaverine and phentolamine, and prostaglandin E1 (alprostadil). In addition to these established substances, several other regimens, such as linsidomine (SIN-1), calcitonin gene-related peptide (CGRP), moxisylyte, and various triple- or quadruple-drug mixtures have been described. In addition, several other compounds as well as different routes of administration are on the horizon and may prove to be effective in the future diagnosis and treatment of erectile dysfunction.

Risk factors for papaverine-induced priapism

Intracorporeal administration of papaverine hydrochloride is frequently used in the diagnosis and treatment of impotence. Priapism is the most serious potential complication of its use. The historical characteristics of 400 consecutive men receiving a standardized dose of papaverine were reviewed in an effort to determine the risk factors for prolonged erections. Younger men (p less than 0.0001) with better baseline erectile function (p less than 0.023) were more likely to have priapism. Despite use of a significantly lower dose, patients with overt neurological disease also had an increased rate of priapism. Patients with a history of coronary artery disease had a significantly lower risk of priapism (p less than 0.05). Patients with a final diagnosis of either psychogenic or neurogenic impotence had a much greater risk of priapism than those with vasculogenic impotence (p less than 0.001). The initial dosage in pharmacological erection therapy may be adjusted according to these risk factors. However, not all patients with psychogenic or neurogenic impotence had priapism and some patients with vascular disease did have priapism. Therefore, all impotent patients are potentially at risk for pharmacologically induced priapism.

Through the eyes of women: the sexual and psychological responses of women to their partner's treatment with self-injection or external vacuum therapy

We prospectively delineated and contrasted the sexual, marital and psychological responses of women to their partner's use of 2 treatments for erectile dysfunction: 1) self-injection of papaverine and phentolamine, and 2) vacuum tumescence therapy. The women were assessed at 5 points during a 12-month period with psychometric questionnaires and clinical interviews. Statistical analysis indicated that the women responded equally well to both treatments. They demonstrated significant increases in frequency of intercourse, sexual arousal, coital orgasm and sexual satisfaction. No significant changes were noted on the psychometric questionnaires. The women reported feeling more at ease in their relationships and characterized sex as more leisurely, relaxed and assured. Negative responses focused on the lack of spontaneity and hesitation about initiating sex. Self-injection and vacuum pump therapy restore potency in men and secondarily facilitate improved sexual function in women.

Comparison of effects following the intracorporeal injection of papaverine and prostaglandin E1

A study group of 240 impotent men receiving intracorporeal injections were divided into 2 groups: the first group received papaverine (60 mg) and the second prostaglandin E1 (PGE1 20 micrograms). The effect of the drugs was evaluated according to the onset of erection, rigidity and the duration of erection; 136 patients were treated with papaverine and 104 with PGE1. The onset of action in these groups was 6.42 +/- 5.39 vs 10.14 +/- 5.41 min; the rigidity score was 3.37 +/- 0.89 vs 3.60 +/- 1.10 and the duration of erection was 49.56 +/- 62.56 vs 63.60 +/- 44.57 min respectively. There was a significant difference in the onset of action (PGE1 was slower than papaverine) and maintenance of erection (longer with PGE1 than with papaverine). Another group of 17 patients received both papaverine and PGE1. The effects of papaverine were better in 4 cases, worse in 5 and equal to PGE1 in 8. This study indicates that compared with papaverine, treatment with PGE1 produces a slower onset of action, a longer duration of erection and fewer side effects.

Intracorporeal needle breakage: an unusual complication of papaverine injection therapy for impotence

We report an unusual complication of papaverine injection therapy for impotence. After 2.5 years of uneventful injections excessive syringe manipulation following needle insertion resulted in needle breakage and a retained intracavernous needle fragment requiring surgical extraction. A synopsis of the presentation, diagnosis and therapy is presented.

Evaluation and treatment of erectile dysfunction following spinal cord injury: a review

The majority of spinal cord injured (SCI) men with upper motor neuron lesions have reflex erections. However, these erections are often not adequately sustained making it difficult if not impossible to have intercourse. The majority of SCI men with lower motor neuron lesions do not have erections. Penile implants are effective in producing erections following SCI. However, they have the disadvantages of being a surgical procedure and of having the risk of infections and erosion of the implant through the skin. Intracavernous injections of papaverine and phentolamine and vacuum erection devices have recently been added to our armamentarium of ways to treat erectile dysfunction. A major concern particularly in SCI men is that papaverine and phentolamine may cause prolonged erections in SCI men. We presently have little data on the use of vacuum devices in SCI men, but preliminary reports on those who are using FDA-approved devices appear promising.

Self-administered intraurethral chlorpromazine: an unusual cause of priapism

Priapism is a prolonged, painful penile erection unaccompanied by sexual desire and not alleviated by ejaculation. The etiologies of priapism are numerous and diverse. Priapism can be a serious adverse effect of psychotropic medications. The case of a 36-year-old man who demonstrated priapism, 48 hours after inserting a crushed chlorpromazine tablet into the urethral meatus of his penis, is reported. Priapism induced by this route of drug administration has not been previously described. The pathophysiology and treatment of priapism are reviewed.

Intracavernous medication for treatment of premature ejaculation

Sixteen men complained of premature ejaculation during a five-month period between May, 1987, and October, 1987. Eight patients entered this study using intracavernous vasoactive drugs as treatment for their problem. The patients, ages twenty-four through fifty-eight (average 42 years), were all physically healthy and taking no medications. Five patients had normal findings on nocturnal tumescence monitor, while 3 patients did not use the monitor. A mixture of phentolamine mesylate, 1.0 mg/mL, and papaverine hydrochloride, 30 mg/mL, was used. The dosage required was from 0.10 mL to 0.40 mL. All 8 patients responded successfully to this treatment. Three patients stated they were cured and stopped the treatment. The other 5 patients continued using the medication after fourteen months. The drug-induced erection lasted between two and four hours despite ejaculation. There have been no side effects through April, 1988. All patients report satisfaction with the results of this treatment. The study showed that intracavernous medication therapy can be successful in the treatment of premature ejaculation.

Classification of sexual dysfunction for management of intracavernous medication-induced erections

A total of 75 patients was placed into 1 of 3 classes of sexual dysfunction based on nocturnal penile tumescence tracings rather than on etiology of the sexual dysfunction. The patients then were given an intracavernous injection with incremental dosages of 0.2 to 1.0 ml. of a combination of papaverine hydrochloride and phentolamine mesylate vasoactive intracavernous therapy. The results of the study were categorized as class 1--mild sexual dysfunction (100% successful with low dosages of medication), class 2--moderate sexual dysfunction (95% successful but larger dosages of medication were required) and class 3--severe sexual dysfunction (a 50:50 chance of a successful treatment and even higher dosages of medication were required). A portable home nocturnal tumescence monitor classification of severity of sexual dysfunction provided a guideline for the intracavernous pharmacological injection initial dosage and the probability of success or failure in patients who desire this form of therapy for male sexual dysfunction.

Intracavernous papaverine in the management of psychogenic impotence

Intracavernous papaverine has found an important place in the management of male erectile failure. The effect of this mode of therapy was studied in 48 patients with psychogenic impotence. The average follow-up for this group of patients ranged from 7 months to 37 months (mean 16.3 months). All the patients in this group were advised sex therapy as an initial mode of therapy. On refusal to undergo sex therapy, they were offered an option of intracavernous papaverine injection. Papaverine appears to break the performance anxiety erectile failure cycle and was noted to have good results. Overall 57.9% patients expressed complete satisfaction with this mode of therapy. One patient (2.1%) developed priapism, which was adequately treated with intracavernous epinephrine. Use of low dosage of papaverine is suggested as an additional mode of therapy in the management of psychogenic impotence.

Priapism: an avoidable complication of pharmacologically induced erection

Priapism is an alarming complication during treatment of erectile dysfunction with vasoactive drugs, particularly papaverine alone or in combination with phentolamine mesylate. An investigational protocol was designed to identify patients who are more susceptible to priapism after intracavernous injection of papaverine alone or with phentolamine. The protocol was applied in 331 men with impotence of various etiology. The association of a positive response to visual sexual stimulation and penile brachial index of more than 0.8 represented a higher risk for post-injection priapism. We were able to reduce the incidence of this compliance to 1% in the last 101 patients.

Priapism: current concepts

The treatment options for the management of the patient with priapism have changed markedly within the past several years. When possible, the underlying cause of the priapism should be identified. Therapy should be guided by the results of aspiration of the blood-filled corpora cavernosa of the erect penis. Early intervention through pharmacologic manipulation or surgical shunting should not be delayed while trying conservative measures.

Pharmacologic erection programs: a treatment option for erectile dysfunction

Pharmacologic erection programs involve the self-injection of vasoactive agents directly into the penis to create an erection. Used with success for erectile dysfunction, this technique has provided another nonsurgical option for rehabilitation patients experiencing sexual dysfunction. The use of these vasoactive agents also has altered understanding of erectile physiology and the associated ability to make accurate diagnoses.

Side effects of self-administration of intracavernous papaverine and phentolamine for the treatment of impotence

Beginning October 1985, 111 men agreed to enter a prospective study of the side effects of low dose papaverine/phentolamine therapy. A total of 46 men dropped out, 30 during the initial phase. The percentage of men with painless nodules almost consistently doubled from one followup examination to the next: 8 per cent at 1 month, 17 per cent at 3 months, 32 per cent at 6 months and 57 per cent at 12 months. The average injection frequency of those with nodules was 2 1/2 times higher than those without nodules. Of the men 41 per cent required an increased dose of medications during followup, and 40 per cent of 50 men had at least 1 abnormality of liver function, most of these involving mild to moderate elevations of alkaline phosphatase and lactic dehydrogenase. Priapism was not encountered during self-injection but it did occur twice in 329 physician-administered injections. Careful regular monitoring of patients should continue as some patients enter the second year of treatment.

Use of prostaglandin E1 for papaverine-failed erections

The use of prostaglandin E1 is introduced as a pharmacologic agent that can produce artificial erections in patients who have failed the initial papaverine test or who were on self-injection programs and later lost rigidity.

Drug-induced priapism. Its aetiology, incidence and treatment

Priapism is characterised by a persistent erection that cannot be relieved by sexual intercourse or masturbation. Although priapism subsides spontaneously in a few days, impotence frequently follows. Both vascular and neural mechanisms are implicated in the pathophysiology of priapism, but it is not clear which initiates the process. Idiopathic cases of priapism are the most frequent (near 50%); other medical conditions that can result in priapism are haematological diseases (mainly sickle cell anaemia and leukaemia), traumatism, and neoplastic processes. Drug-induced priapism comprises about 30% of cases. The drugs most frequently implicated are psychotropic drugs (phenothiazines and trazodone), antihypertensives (mainly prazosin) and heparin. Recently, the intracavernosal injection of vasoactive drugs (papaverine and phentolamine) has been described in patients treated for impotence. With the exception of heparin, an alpha-adrenergic blocking mechanism has been suggested in the priapism-inducing action of these drugs. A significant number of anecdotal case reports link priapism and drugs, and it is possible that certain cases of idiopathic priapism could be reclassified if accurate pharmacological anamnesis were to be performed. Priapism must be considered a urological emergency. Surgical procedures are the most preferred treatment for this condition but, in selected cases, drug treatment seems to be an alternative approach.

Erectile responses to intracavernous papaverine and phentolamine: comparison of single and combined delivery

In a prospective study of 15 consecutive impotent patients we evaluated the erectile responses to intracavernous injections of standardized doses of papaverine and phentolamine alone and in combination. Of the 15 patients 13 achieved a full erection with the drug combination, whereas only 6 achieved a full erection with papaverine and 1 with phentolamine. Our results suggest an effective alternative to the use of papaverine alone, whose long-term sequelae have been shown to be deleterious.

Is phentolamine stable in solution with papaverine

Although the intracorporeal injection of mixtures of phentolamine and papaverine is used commonly in the diagnosis and treatment of erectile dysfunction, pharmacological data relating to the stability of such drug mixtures are lacking. The stability of phentolamine mesylate in aqueous solution and in solution with papaverine (0.83 mg. per cc phentolamine and 25 mg. per cc papaverine) was ascertained by high performance liquid chromatography and gas chromatography with mass spectrometry. No degradation of phentolamine occurred during 40 days whether the drug or drug combination was refrigerated or stored at room temperature. Phentolamine is stable for at least 40 days when mixed with papaverine.

The use of a vacuum constrictor device to augment a partial erection following an intracavernous injection

Intracavernous injections and vacuum constrictor devices have been used for the nonoperative management of impotence and sexual dysfunction. Although most men are able to use these methods successfully, it currently is well known that up to 30 to 35 per cent of the patients may have only a partial response to the injections. We observed 22 men with partial tumescence after an intracavernous injection of papaverine (15 to 30 mg.) and phentolamine (0.5 to 1.0 mg.). The penis was not rigid and the buckling pressures never exceeded 50 mm. Hg after 20 minutes of observation. In each case we immediately applied a vacuum constrictor device because these devices had been used successfully by other men with similar diagnoses. A total of 21 men responded within 30 to 60 seconds and achieved a rigid erection with buckling pressures of greater than 100 mm. Hg (16) and 60 mm. Hg (5). These findings indicate that a vacuum constrictor device may be used to augment a partial response to an intracavernous injection and that the availability of injections and vacuum constrictor devices provides these men with a more complete nonoperative program.

Nocturnal penile tumescence predicting response to intracorporeal pharmacological erection testing

Although response to intracorporeal pharmacological erection testing has been proposed to determine the etiology of impotence, physiological criteria predicting this response have not been established and the literature includes conflicting results regarding which patients respond to pharmacological erection therapy. In this study 37 impotent patients underwent a diagnostic nocturnal penile tumescence evaluation (including measurements of rigidity, pulsations and bulboischiocavernosus muscle activity) and the results were correlated with subsequent response to intracorporeal pharmacological testing. Most but not all patients with psychogenic impotence and all with neurogenic impotence responded with good erections. For vasculogenic impotence response rate depended upon impairment severity determined from nocturnal penile tumescence measurements; none of the severe cases versus 90 per cent of the milder cases responded. The results indicate that response to intracorporeal pharmacological testing does not accurately distinguish psychogenic from organic impotence, is best for neurogenic impotence and worst for severe vasculogenic impotence, and can be predicted accurately by nocturnal penile tumescence measurements.

Patient acceptance of and satisfaction with vasoactive intracavernous pharmacotherapy for impotence

Patient acceptance of and satisfaction with a trial of vasoactive intracavernous pharmacotherapy for impotence among 372 men were retrospectively analyzed. Drop out from the dosage determination phase and the training for injection phase was similar, 9.7 and 8.4 per cent, respectively, while 31.4 per cent of the patients dropped out of the home injection phase. Tachyphylaxis, inconvenience of the procedure or the frequent followup visits required, side effects and concern about unknown long-term effects were the main reasons patients cited for dropping out of the trial. The degree of satisfaction among patients who entered the home injection phase was high. Only 55 patients who dropped out of the trial chose implantation of a penile prosthesis. Vasoactive intracavernous pharmacotherapy is an effective treatment for impotence of various etiologies, and in a carefully selected group of patients the acceptance of and satisfaction with this therapy are high.