ABC of sexual health: Erectile dysfunction

Treatment of erectile dysfunction is initiated after taking a patient's history and examination (see previous articles), and possibly investigation.

Medical management

In highly selected patients with a clear psychological problem, psychotherapy or sex and couple therapy can be used, but these are time consuming and are available to only a small number of patients. Nevertheless, it is essential to treat the whole person and not just his penis. Counselling, alone or separately from sensate focus techniques,¹ should be considered as an option. Erectile dysfunction is of a largely psychological nature in a third of patients, in a third it is largely physical, and the remaining third have both physical and psychological factors.

Oral treatment

Sildenafil The first line of treatment for erectile dysfunction with most practitioners at the time of writing is oral sildenafil. Despite much exaggeration of its seemingly magical powers it is a very significant advance in management, with an overall success rate of 69%.² Initial reports suggest an effective response of 88% in those who have psychogenic causes, and the treatment may have its effect by breaking the failure cycle. It seems to be well tolerated and particularly effective in men with post-traumatic spinal cord injury, who have partial preservation of erectile function.³ In diabetics, the success rate is lower, averaging about 50% of those treated.

Sildenafil is marketed as tablets of 25, 50 and 100mg. The optimum dose is found by starting at 50mg and titrating upwards or downwards. The most effective dose seems to be 50-100mg. Doses greater than 100\g do not appear to improve the response, although the side effects are more common. These are headache (16%), flushing (10%), dyspepsia (7%), nasal congestion (4%), and transient green/blue tingeing of vision in 3% with higher doses.² Priapism has not been recorded. A total contraindications is concurrent use of nitrates for angina or hypertension.⁴

The drug needs to be taken an hour (or 1½ hours after a meal) before sexual activity and does not work unless there is physical or mental sexual stimulation, a fact which needs to be spelled out carefully to some patients (and their partners).

Yohimbine is not licensed but has been used for many decades at a dosage of 5-15mg daily. Many specialists believe its effects to be largely placebo related.

Injected treatment

Alprostadil (prostaglandin E₁) was given a product licence in 1994 and is supplied in 5, 10, and 20mg doses. Patients are usually started on a small dose in the clinic but are advised that the injection may be more effective in a more relaxed atmosphere at home. Lower doses are more likely to be effective in counteracting neurological disease.

Papaverine was introduced in the early 1980s as the first effective intracavernosal injection treatment for erectile dysfunction. Given in doses of 7.5-90 mg, initially alone and later with phentolamine as a synergist in the ratio of 30:1, these treatments did not have a product licence but were effective, cheap, and easy to use, although they had a high incidence (up to 25%) of prolonged erection.

Triple therapy (a combination of papaverine, phentolamine, and alprostadil) is used for patients in whom individual drugs have failed. Treatment usually starts at a dose of papaverine 30mg, phentolamine lmg, and alprostadil 20mg.

Vasoactive intestinal polypeptide (VIP), 0.025mg in combination with phentolamine (1mg or 2mg), has recently received a licence, and there have been early reports of success from trials.

Consent forms for treatment may be used, especially if unlicensed preparations are being prescribed. All these treatments are intracavernosal and should be initiated under careful medical supervision. Initial doses for all compounds are usually low because of the risk of priapism (an erection lasting longer than 4-6 hours). As this may occur with intracavernosal injections, it is essential that practitioners familiarise themselves with the treatment of priapism (see box).
 

An intracavernosal injection of alprostadil

Intraurethral treatment

If sildenafil does not work the medicated urethral system for erection (MUSE) can be tried. It is a pellet of prostaglandin (in doses of 125, 250, 500, or 1000mg) which is placed in the urethra through the meatus and produces an erection after about 15 minutes. This treatment is a popular choice for both patients and physicians because of its ease of use, but, in common with other prostaglandin treatments, it has a relatively high incidence of penile pain and also appears to have a low efficacy which may make patients less willing to continue the treatment.
 

MUSE (alprostadil)

Hormonal treatment

Testosterone is usually ineffective in treating erectile dysfunction in patients with normal serum testosterone concentrations and may exacerbate the problem by increasing a patient's sexual drive without improving his ability to perform. It may be given orally but is usually given as an intramuscular depot injection at intervals of 3-4 weeks, by daily patches, or by implants every six months. Great care should be exercised in patients with possible carcinoma of the prostate, and levels of prostate specific antigen (PSA) should be checked initially and every six months.

Ethical considerations

Some clinics insist on seeing both members of a couple before starting treatment, but many clinics see only the male partner and are therefore totally reliant on his history. However, many patients are not in a relationship and are afraid to embark on one because of fear of erectile failure. The confidence gained by the certainty of obtaining an erection enables a proportion of this group (whether their problem is psychological or physical) to initiate a relationship, and many patients will have a resumption of normal erectile function.

Misuse of these drugs is a consideration. There are isolated reports of the use of intracavernosal injections in association with prostitution and anecdotal reports of their use in sex shows, and this may become a problem with oral sildenafil. After a drug is prescribed there is clearly no possibility of monitoring its use. It is impossible to check for paedophile and other sexual offences, and patients in these groups may receive help to restore erectile function, with obvious medicolegal implications.

The treatment of homosexual men may be a reflection of an individual doctor's prejudices. As a patient's history is the only evidence available, it would clearly be discriminatory not to treat men who have male partners. Some doctors prefer not to, or refuse to, treat patients who are infected with HIV, but, unless there is uniform testing of all patients, this information is usually available only if the patient volunteers it.

Erectile problems are common in men infected with HIV, and some clinics are now treating infected patients, who are usually in long term relationships. Before treatment, both partners are usually counselled about the risks involved and are asked to give signed agreement to treatment. Again, as in heterosexual relationships, injections may be used in a commercial situation. The occurrence of HIV being knowingly transmitted after treatment to restore erectile function is extremely rare, and there have been no reported cases in the United Kingdom.

Vacuum devices

There are many vacuum devices, either manual or battery operated, currently available for treating erectile dysfunction. The penis is placed in a plastic tube, and venous blood is drawn into it by suction. Once it is erect, a rubber constriction ring is placed at its base to prevent detumescence. These devices are generally safe, but the erection should not be maintained for more than 30 minutes as the penis may become cold and painful because of the constriction. Vacuum devices are the preferred option for patients who are afraid of injections or in whom injections have not been successful. They cost from £100 to £300 and are usually supported by manufacturers' helplines and money back guarantees.
 

Vacuum pump and constriction rings

Surgical management

Surgery for venous leakage and microvascular techniques for revascularisation of the corpora are rarely used, and the results are not good. The only surgical treatment of any value is inserting a penile prosthesis. Since their advent in the mid-1970s, prostheses have developed considerably from poorly concealed, low cost, trimmable silastic rods to ones made of silicone outside a metal core and self contained, inflatable cylinders. Inflatable devices are either two part prostheses with a combined reservoir and pump that sits in the scrotum or three piece models in which the pump alone sits in the scrotum and the reservoir lies in the lower abdominal wall.

Indications for use of prostheses have changed with the development of intracorporeal injections, vacuum devices, and oral preparations. Patients commonly needing surgery are those who have had pelvic surgery or who have diabetes or atherosclerosis. Prostheses are also useful in patients impotent with Peyronie's disease (which seems to be getting commoner) as they correct the deformity as well as the impotence.

Cost apart, the choice of prosthesis is up to the patient. The semi-rigid cylinders do stick out and are therefore not suitable for younger men with children in the house, those participating in swimming and sporting events, and naturists. The cost of an inflatable prosthesis is not countenanced by some NHS trusts, but persuasion may be possible in a particularly deserving case such as a young diabetic patient whose marriage is at risk.

Three piece penile prosthesis in which the pump alone sits in the scrotum and the reservoir lies in the lower abdominal wall

Operative procedure

The operation is done under regional or general anaesthesia. Circumcision is often necessary with many semi-rigid prostheses, so this should be done initially.

The corpora are exposed and opened through an incision large enough to insert a Hegars dilator and are dilated full length from just inside the glans to the ischium, compressing the normal corpora. This may be difficult with fibrotic penises, after priapism, or with Peyronie's plaques. With multipart prostheses, all components are filled with saline and the tubing connected, the pump is placed in the most dependent part of the scrotum, and the reservoir is put under the rectus sheath.

Postoperative management

Pain relief must be provided as the operation is painful.

Antibiotics - A broad spectrum antibiotic should be taken orally for a week after the operation.

Voiding - If there are difficulties with voiding, use clean intermittent catheterisation.

Postoperative use - Semi-rigid prostheses may be used after four weeks. Patients can be taught how to pump up an inflatable prosthesis after four to six weeks.

Postoperative problems

Infection occurs in 1-10% of cases, depending on the difficulty of the procedure. Repeat operations are more prone to infection. It is usually necessary to remove the infected part or complete prosthesis, and, although difficult, it is possible to replace it six months later.

Erosion is usually due to infection or to an unsuspected breach of the urethra at surgery.

Glans ischaemia occurs with vascular compression or damage.

Supersonic transport (SST) deformity (also known as Concorde deformity) with glans droop may be unsightly but may not matter if there is an additional glandular erection.

Mechanical problems are now uncommon. If they occur the part should be replaced.

Prognosis

Penile prostheses give acceptable results. In many large series over 80% of patients and their partners were satisfied with the results. In those with Peyronie's disorder, a prosthesis straightened the penises of 70%. There is no real age limit for the operation, but a prosthesis should not be inserted unless it is going to be used.

Appearance of a penis after insertion of an inflatable prosthesis, with the device deflated (top) and inflated (above)

Wallace Dinsmore, consultant physician, Royal Victoria Hospital, Belfast

Christine Evans, jconsultant urologist, Clwyd Hospital, Rhyl

The picture of Viagra is produced with permission of Associated Press.BMJ 1998;317:387-90

studentBMJ 1999;07:394-436 November ISSN 0966-6494

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3. Derry F, Glass C, Dinsmore WW, et al. Sildenafil (Viagra): a double-blind, placebo controlled single dose, two way cross over study in men with erectile dysfunction caused by traumatic spinal cord injury. J Neurol Sci 1997;150(suppl):S134(abstract 2-52-10).
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