Shared Care Management: the primary care perspective

M.G. Kirby

INTRODUCTION

Impotence or erectile dysfunction (ED) is the inability to maintain an erection sufficiently long to fulfil sexual activity. It has been estimated that up to 10% of the adult male population suffer from this disorder.¹ Further, only a small subfraction asks for help. The condition is age-related with an incidence at age 65 of 25%.² The incidence can be affected by other risk factors or associated conditions. In particular 35–50% of diabetics may experience ED.³ Traditionally men with ED have been referred to specialists e.g. urologists, psychiatrists and diabetologists/endocrinologists, often with long waiting lists. The referral period can be highly dependent on the country and there can even be considerable regional variations. Increasingly, however, several factors will lead to an increasing number of men presenting to their primary care physician:

• The advent of  Viagra and other simple safe and effective treatments.
• Increasing media coverage of ED.
• A change in the traditional reluctance to seek advice.
• The ‘greying’ of the population.
• Limited specialist access in most healthcare environments.

On this basis the primary care physician must gear up to be able to provide appropriate diagnosis, disease management and long-term follow-up and counselling. Although ED does not affect mortality it can have a major negative effect on patient and partner well being and quality of life. The primary care physician and supporting local infrastructure is ideally placed to provide appropriate advice and/or medical and non-medical treatment and support.

ED will appear in most men at least once in their life. It is considered significant only if it occurs on more than an occasional basis, such that it interferes with normal sexual functioning. The problem may also affect a man’s interactions with his family and associates, and the problem tends to be compounded by unrealistic expectations of continuing sexual prowess, particularly as a result of most men’s reluctance to admit to the problem, or even to discuss it with their peers. The situation is often not discussed with the partner and some men may hide their difficulties, which may make the relationship worse, because apparent lack of sexual interest may be misinterpreted as a sign of unfaithfulness.

An open approach is most important and some couples are prepared to accept impotence as an inevitable consequence of the passage of years. However, increasing press and television coverage of this subject is removing some of the traditional reluctance to consult. With increasing life expectancy of men, those in their 70s no longer feel old and often wish to continue with an active sex life. Some of these men may have younger partners and are now requesting medical help to resolve the problem.

With the advent of Viagra and other simple, effective and safe therapies, there is an increasing awareness within the community of the improved prospects of the patient with ED. However, the bulk of the increasing number of males is looking for a quick fix and does not necessarily wish to engage in psychosexual counselling. On this basis, the advent of orally active agents such as Viagra and injectables (various prostaglandin preparations) would be particularly attractive and encourage patient presentation.

It is perfectly natural that elderly couples should wish to continue to share an active sex life. This may be less related to sexual drive and more related to the giving of comfort and security that comes as a result of intimacy. It is not uncommon for older people to report that their sex life is more satisfying than it was in their younger days and this naturally has beneficial effects on both physical and psychological health. There are several factors that predict the continuance of sexual activity past 70 years:

• Greater importance of sex in their younger days.⁵
• Better psychological health.⁶
• Earlier age at first intercourse.⁷
• Better subjective health in women.⁸
• A stronger sexual drive in men in their 20s.⁵

The wider availability and use of hormone replacement therapy (HRT) for women will almost certainly have an impact on the enthusiasm for sexual activity in the older woman. The genital consequences of oestrogen deficiency, especially dyspareunia and urinary symptoms, are significant factors in women withdrawing from sexual activity. It has been shown that, in women continuing sexual activity in the second half of their lives, there is a reduced risk of genital atrophy.⁹

These factors have led many primary care physicians to consider the advisability of setting up an in-house service for ED. This may be partly due to a desire to develop new multidisciplinary skills that would benefit such patients and to be able to offer the patient assessment and appropriate treatment in a non-hospital setting. There are advantages in using existing communication skills based around an established doctor/patient relationship which is integral with the knowledge of the patient's physical, social and psychological history.

There may be financial advantages to the practice in terms of a reduction in unnecessary referrals to outpatient urology departments. When expertise is developed there may be opportunities to assess and treat patients of other primary care physicians in the area as a local provider unit. The use of trained nurses will keep waiting times comparatively short and it is important to have a line of communication with local psychosexual therapists.

NORMAL MECHANISMS

The knowledge of the physiological mechanisms of ED has resulted in the development of various realistic treatment options. Erection of the penis depends on the adequate filling of the corpora cavernosa with blood at systolic pressure. Arterial blood enters from the paired cavernosal arteries, which are the terminal branches of the internal iliac arteries. The mechanism of the erection is controlled by the autonomic nervous system. Parasympathetic nerves from S2–S4 are the principal mediators of erection while sympathetic nerves from T11–L2 control ejaculation and detumescence. Basic research into the smooth muscle physiology of the erectile tissue and the identification of neurotransmitters such as nitric oxide and acetylcholine has opened the pathway to new treatments (Fig. 42.1).

Figure 42.1. (a) The erectile mechanism is mediated by nitric oxide via a second-messenger system involving cyclic guanosine monophosphate (cGMP). Detumescence results from breakdown of cGMP by phosphodiesterase type 5. It has been hypothesized that ED results from reduced tissue cGMP levels. (GTP, guanosine triphosphate.) (b) Phosphodiesterase (PDE) type 5 inhibition e.g. by sildenafil prevents cGMP breakdown and thereby enhances the normal erectile response in a patient with ED. (From ref. 31 with permission.)

a

b

CAUSES

The human sexual response is extremely complex; problems with potency are often multifactorial and there is a need for an integrated approach that may have to be multidisciplinary, involving the primary care physician, urologist, psychologist or psychiatrist and specialist nurse. The causes of ED can be divided into six groups —psychogenic, neurogenic, endocrine, arteriogenic, drugs and miscellaneous. A summary is given in Table 42.1.

Table 42.1. Causes of erectile dysfunction*

Psychogenic - Anxiety, Depression

Neurogenic - Trauma Myelodysplasia (spina bifida) Intervertebral disc lesion Multiple sclerosis Diabetes mellitus Alcohol Pelvic surgery

Endocrine Hormone deficiency — low testosterone and raised SHBG; high prolactin Thyrotoxicosis

Arteriogenic Hypertension Smoking Diabetes Hyperlipidaemia

Venous Functional impairment of the veno-occlusive mechanism

Drugs Central and/or direct effect (most commonly implicated, antihypertensives, antidepressasnts and LHRH analogues)

Miscellaneous Peyronie's disease Penile trauma Opiate use Lack of exercise Obesity Drug abuse

* These conditions are not mutally exclusive - many cases of ed are multifactorial.

Psychogenic impotence

Psychogenic stimuli can inhibit erection, mainly through stimulation of the sympathetic nervous system: the increased sympathetic tone interferes with the mechanism of smooth muscle relaxation that underlies erection. Once failure has occurred, the problem is self-perpetuating, with each failure increasing anxiety. Psychogenic impotence is the commonest cause of intermittent erectile failure in young men. However, it is usually secondary to some organic dysfunction in middle-aged and elderly men.¹⁰ Diagnostic clues include the following:

• Life event at time of onset.
• No physical illness.
• Baseline tests normal.
• Early morning and nocturnal erections intact.
• Normal erection during masturbation.
• Intermittent, depending on partner.
• Sudden onset.

Neurogenic impotence

ED may be caused by changes in the central nervous system, at the level of either the brain, the spinal cord or the peripheral nervous system, and there are usually other clinical signs of neurological involvement. For example, a prolapsed intervertebral disc may cause pressure on the cauda equina and peripheral neuropathies (usually caused by diabetes or alcoholism) may affect the S2–S4 segment. Upper motor neuron lesions dissociate the sacral reflex arc from the midbrain, hypothalamic and cortical controlling mechanisms. Diagnostic clues include the following:

• Inability to masturbate.
• Absent or infrequent morning or nocturnal erections.
• Postural hypotension.
• Urinary symptoms.
• Diminished sweating in lower limb.
• Intermittent attacks of diarrhoea.
• Loss of orgasmic sensation.
• Absent cremasteric, anal or pubocavernosal reflexes.
• Diminished testicular sensation.

Endocrinological impotence

Endocrinological impotence may result from abnormalities in serum testosterone, prolactin or thyroxine. Free serum testosterone concentrations fall progressively with age because the testes produce less hormone and more androgens are bound to sex-hormone-binding globulin (SHBG), the concentration of which increases with age. Falling free testosterone concentrations are associated with a loss of libido and reduced frequency of erections. Diagnostic clues include the following:

• Beyond middle age.
• Progressive loss of erections under all circumstances.
• Recent loss of libido.
• No spontaneous sexual fantasies.
• Feminization.
• Gynaecomastia or testicular atrophy.
• Low testosterone.
• Raised levels of SHBG.
• Raised gonadotrophins.
• Raised prolactin.
• Diminished beard growth.

Raised prolactin concentration is also associated with reduced circulating free testosterone, and decreased potency may be an early feature of raised serum prolactin levels.¹¹ This may be idiopathic or due to drug use, renal failure or a pituitary tumour.

Vascular impotence

Erection may be impaired by either arterial insufficiency or a disorder of the veno-occlusive mechanism, but often both are present. In older patients, arteriosclerosis is the most common cause.^12,13 Changes in the fibroelastic components of the lacunar trabeculae may cause venous leakage and Peyronie’s disease may be associated with a venous leak. Diagnostic clues include the following:

• Insidious onset.
• Inability to masturbate.
• No morning or nocturnal erections.
• Evidence of poor blood supply to fingers, feet or penis.
• Angina.
• Worsened by the use of small amounts of alcohol.
• Smoking.

Medication

Drug therapy is not an uncommon contributory factor in ED.^14,15 Slag and colleagues¹⁶ showed that, in a group of over a thousand men attending medical outpatients, 34% were suffering from ED and, of those investigated, medication was thought to be the cause in 25%.

As the patients grow older they are much more likely to be receiving a variety of drugs and it is important to review their medication, as this simple intervention can result in the return of normal sexual function.^17,18 Antihypertensives are the group of drugs most commonly associated with this problem. These drugs are often used in combination, which may compound the effect. The incidence of ED is higher in untreated hypertensive men than in normotensive individuals, probably owing to arteriosclerosis. The association between beta blockers and ED is well known,^14,15 and a change to one of the more cardioselective beta blockers may be helpful. Centrally acting antihypertensives such as methyldopa and clonidine may also cause problems, but alpha blockers such as doxazosin are much less troublesome and may even improve the situation. Thiazide diuretics may also be a problem.

The MRC trial¹⁸ showed a rate of 36% ED in patients on bendrofluazide, and withdrawal of diuretic often led to an improvement in sexual function. Spironolactone is an aldosterone antagonist and acts as a potassium-sparing diuretic. There are many reports of its association with gynaecomastia, reduced libido and an incidence of between 4 and 30% of ED. This drug may act as an anti-androgen by inhibiting the binding of dihydrotestosterone. Antipsychotics, antidepressants and anxiolytics may all cause problems due to their central effect, anticholinergic effect and effect on the hypothalamus. The increasing use of anti-androgen drugs, particularly for the treatment of hormone-sensitive prostate cancer, leads to a major incidence of ED.

It is impossible to be comprehensive in this text as there is an ever-increasing list of drugs associated with this problem. The mechanisms are complex but there is often a relation to reduced libido. The common offenders are cimetidine, digoxin, nicotine, alcohol and opiates.

Miscellaneous conditions

Obesity, lack of exercise and general lack of fitness, drug and alcohol abuse may often be contibutory factors in patients presenting with ED. Peyronie’s disease, other penile deformities and penile trauma can also cause discomfort, leading to loss of function.

MANAGEMENT OF ED IN THE PRIMARY CARE SETTING

The advent of more widespread disease awareness and the availability of orally active agents have prompted the development of guidelines to be used specifically as the potential basis for patient management in the primary care setting (Chapter 43). The guidelines include diagnosis and treatment, both medical and non-medical involving lifestyle modification.

Diagnosis

A careful history and physical examination are required to help elucidate the cause of ED and to decide whether the problem is psychogenic or organic in origin. There may be clinical signs of recognized risk factors. Men with ED usually have normal libido and unimpaired ejaculatory function.

Psychogenic ED may begin suddenly, following some life event. Early morning, self-stimulated and spontaneous nocturnal erections are often preserved. By contrast, organic impotence is characterized by a progressive loss of erectile function; it is consistently present and associated with loss of early morning and nocturnal erections. A detailed psychosocial and psychosexual history is required to explore sources of relationship difficulties, sources of anxiety or stress and to establish whether the partner is sympathetic towards the problem. Specific questions, such as the following, may be helpful:

• When did you last have successful sexual intercourse_
• How frequently do you have problems with your erections_
• What sort of problems have you had with your erections_
• Have you discussed this matter with your partner_
• Do you have any relationship problems_
• Have you heard of any treatments which may help your problem_
• How interested are you in sex and how often do you have sexual desires_
• Do you have any current physical problems_
• What were your childhood experiences and parents’ attitude to sexuality_
• Did you have any abnormal sexual experiences during adolescence_
• Are you content with your sexual relationship_
• How do you rate yourself as a sexual partner_

Focused examination

1. Examine the size and shape of the penis, in the flaccid state and, where appropriate, in the erect state, to observe any bowing or distortions.
2. Look for any inflammation under the foreskin and determine whether the foreskin retracts normally.
3. Examine the testes with regard to size, shape and consistency and palpate the epididymis and vas deferens to detect any abnormal swelling or varicocoeles.
4. The prostate should be of the same rubbery consistency as the tip of the nose. The presence of induration or a palpable nodule should raise the suspicion of prostate cancer.

General examination should include the endocrine, vascular and neurological systems. Look for loss of secondary sexual characteristics, and for signs of liver disease such as gynaecomastia, palmar erythema, spider naevae and leuconychia. Vascular assessment should include measurement of blood pressure, cardiac status and lower extremity pulses. Look for arterial bruits, poor capillary return and signs of diabetes. Examination of the fundi may reveal changes of hypertension or diabetes, such as haemorrhages, cotton-wool spots or arteriovenous nipping. A brief neurological examination should be made to exclude abnormal reflexes, muscular tone or motor loss. The S2–S4 dermatomes should be evaluated by testing the perineal sensation and anal sphincter tone (Fig. 42.2).

Figure 42.2. Important htmlects of the physical examination in men with ED. (Adapted from ref. 31 with permission.)

Summary

Decide:

• What is the likely cause of the complaint_
• What are the expectations and motivations of the man and his partner for further diagnostic tests and treatment_

Refer if:

• Evidence of significant peripheral vascular disease.
• An organic cause in a young man.
• Hypogonadism in a young man.
• Severe psychosexual problems.

Investigations

It is important to exclude undiagnosed diabetes mellitus with the urine dipstick test, which may also indicate proteinuria or suggest the presence of infection. Blood investigation, where necessary, may include one or any of the following tests depending on history and clinical findings:

• Full blood count.
• Liver function tests.
• Renal function tests.
• Thyroid function tests.
• Blood sugar.
• Testosterone.
• Sex hormone binding globulin (SHBG).
• Prolactin.
• Luteinizing hormone.
• Fasting lipid profile.

Self-administered tests of nocturnal erections may be made with the snap gauge band¹⁹ and the Rigiscan device (Dacomed, Minneapolis, MN, USA). Unless the problem is obviously psychogenic, a trial injection of an intracavernosal vasoactive agent will be helpful and will distinguish responders from non-responders and help select candidates for self-injection treatment.

More specialized investigations need be performed only when a detailed knowledge of the cause of ED is required. These include colour Doppler imaging and pharmacocavernosography.

Psychosexual counselling

There are many psychological causes that diminish the capacity for erectile response (Table 42.2). These include anxiety, depression, relationship problems, negative experiences and sexual technique problems. Psychosexual therapy began at the beginning of this century with the use of Freudian psychoanalysis. In 1970, Masters and Johnson described a treatment programme involving a combination of behavioural and psychotherapeutic elements and they reported a 70% success rate after 5 years of follow-up. Current day therapy concentrates on the behavioural htmlects and aims to reduce performance anxiety by means of a programmed relearning of a couple’s sexual behaviour. This aims to break the vicious circle of erectile failure that is reinforced by the anticipation of failure the next time (Fig. 42.3). Sex therapy consists of a graduated programme of homework assignments combined with education and follow-up to overcome barriers to progress:²⁰

Figure 42.3. Breaking the cycle of erectile failure.

1.   Dealing with predisposing factors;

• Underlying problems
• Education
• Communication skills
• Giving permission.

2.   Dealing with precipitating factors;

• Emotional support
• Physical treatments.

3.   Dealing with perpetuating factors;

• Patient confidence building
• Redefining success
• Allowing expression of feelings
• Partner — open discussion — must be supportive
• Interpersonal communication
• Breakdown problems with intimacy
• Easing pressure — stress management
• Joint responsibility for the partner with the difficulty.

Medical management

Ever since the advent of penile prostheses, there has been a continuous improvement in the availability of user-friendly, reliable and dependable interventions with potential in the management of ED. Traditionally in any ED healthcare management system patient education and training is rate limiting and expensive. In the primary care system; at least, this can be overcome with the help of trained nurse practitioners. Under these circumstances although training in vacuum devices and injection therapy is time consuming, in motivated patients the success rate can be high. The advent of sildenafil, however, is likely to change radically the patient-healthcare provider interface.

The enthusiasm for  taking a pill for the treatment of ED has been traditionally shown by the OTC use of various homeopathic remedies including yohimbine.²⁶

Sildenafil (Viagra) has recently been approved in the US and worldwide approval is anticipated within the next year. This agent is a selective inhibitor of phosphodiesterase type 5. Inhibition of this isoenzyme elevates cavernosal cGMP that produces an erection in ED patients with little effect on normal sexual activity. This drug has been shown to be effective in organic and psychogenic impotence and in diabetics and spinal injury patients. Some degree of success is also observed in post radical prostatectomy patients with surgery-induced ED. Given the reliability of the response to Viagra and the side effect profile, the drug may in fact become a diagnostic for ED in the primary care setting. One can imagine the scenario that only when an inadequate or poor response to Viagra is observed, would specialist referral be required.  However, as with any new class of agent, care should be taken on prescribing Viagra. In addition to an absolute contra-indication for nitrates the full side effect profile of Viagra may only become known after several years of further investigation. It remains, however, that the advent of Viagra represents for many patients a quantum leap in the management of ED.

The biggest problem with the management of this condition in primary care is lack of time and this may be overcome with the help of trained nurses. Teaching vacuum or injection therapy is time consuming but the careful selection of highly motivated patients is rewarding. Both these techniques are well tried and tested and have good success rates, but only if the technique is properly taught.

Intracavernosal injection (ICI)

This method of treatment (Chapter 31) was introduced in the early 1980s and was a significant advance in the treatment of ED.²¹ Papaverine, alone or in combination with phentolamine, and prostaglandin E1 (PGE1) (alprostadil) are the agents most widely used (Table 42.3). Alprostadil has also been studied as an intra-urethral preparation, given by means of a unique applicator.²² There appears to be a good response to intra-urethral alprostadil; systemic effects are uncommon and complications such as priapism and penile fibrosis are less common than when the drug is given by penile injection. Papaverine and PGE1 are both muscle relaxants and probably have a similar mode of action in ED. PGE1 is a naturally occurring substance, metabolized locally following ICI in cavernosal tissue with little systemic penetration. The risk of priapism (defined as an erection lasting more than 4 hours) is very low. Occasionally it does cause a dull throbbing ache in the penis and occasional giddiness and nausea has been reported.

Moxisylyte (Erecnos®) is an alternative intracavernosal injection that has recently been introduced. It facilitates an erection in men with ED (Table 42.4). Erecnos® is a selective alpha-1 blocker that facilitates tumescence within 10 minutes. In a study including more than 300 men with ED, 90% of those receiving Erecnos® reported an erectile response, sufficient for penetration in 50% of cases.23 If a programme of penile injection therapy is commenced, it is necessary to obtain informed consent from the patient, warning him about the risk of priapism; clear instructions should be given regarding what to do should this occur,24 and if so, it is essential to instruct him to return to the GP concerned or to go to the local hospital for treatment. In the event of a prolonged erection, detumescence may be achieved by inserting a butterfly needle into one of the corpora, htmlirating 20-40 ml of blood. This may take approximately 20 minutes and may be complemented by the concomitant administration of an alpha-adrenergic antagonist. Patients should also be warned of the long-term risk of scarring at the site of injection, and instructed to use the injections no more than twice a week. This treatment should be used with particular caution in men under the age of 50 and in those with neurological disease or where psychological features predominate. Larger doses may be necessary in patients with hypertension, peripheral vascular disease or hyper-cholesterolaemia (Fig. 42.4).

Figure 42.4. Self-injection technique. (From ref. 31 with permission.)

Figure 42.5 A typical vacume erection device (a), which is placed over the penis and used to induce an erection that is maintained with a constrictor ring (b). (From ref. 31 with permission.)

Vacuum devices

Vacuum devices are a non-invasive, inexpensive and simple treatment for a man who does not respond to intracavernosal injection.²⁵ The penis is placed inside a cylinder where a pump is used to create a vacuum that pulls blood into the penis. A rigid erection is produced within minutes. A tension ring is then pulled off the cylinder onto the base of the penis, where it remains during sexual activity. Some patients complain that the erection produced is cold and lifeless and the tension ring may cause discomfort, especially during ejaculation. The technique requires good manual dexterity on the part of the patient and the partner. The ring should be removed after 30 minutes of use. Various devices are available (Chapter 34), ranging in price from £150 to £250. They are usually available with a money-back guarantee and are particularly useful in older and less fit men (Fig. 42.5).

• Side effects.
• Ineffectiveness.
• Lack of spontaneity.
• Partner dislike.
• Failure to engage partner at an early stage.
• Interpersonal problems.

If the patient is shown to be hypogonadal, androgens can restore both libido and potency.²⁹ There is no useful therapeutic effect in patients whose free testosterone concentrations are within the normal range. Oral testosterone supplements are less effective than parenteral preparations and are known to have hepatotoxic side effects. Testosterone patches may be a useful alternative. Clinical and biochemical evaluation of the prostate with prostate-specific antigen (PSA) and monitoring of blood lipids is necessary when treating men with testosterone.

Figure 42.5. A typical vacuum erection device (a), which is placed over the penis and used to induce an erection that is maintained with a constriction ring (b). (From ref. 31 with permission.)

Topically acting vasodilating drugs

The use of these drugs is not new (Chapter 29). Glyceryl trinitrate has been used with some limited success.³⁰ Where there is loss of tumescence following penetration, caused by the pelvic steal syndrome or in the presence of a venous leak, improvement may be achieved using a constrictor ring in addition to intra-urethral alprostadil.

Surgical treatment

Men who do not respond to the self-injection technique, or the vacuum device, may benefit from surgery. Many of these patients will have significant arterial or venous disease or penile corpus cavernosum fibrosis. There are three surgical options available: vascular bypass surgery for arterial or venous abnormalities (Chapter 36), ligation for venous incompetence (Chapter 35) or implantation of a penile prosthesis (Chapters 37 ,38 ,39 ).

CONCLUSIONS

The management of ED has been revolutionized by the development of new therapies and it can now be undertaken by any physician with an interest in this subject. In the UK this is usually a urologist but may also be a diabetologist, specialist nurse or primary care physician. With the advent of intra-urethral therapy and oral therapy, it is likely that there will be a huge increase in demand for treatment and the emphasis may swing towards the primary care physician. There will be cost concerns for purchasers in the current climate of limited resources and there will be challenges to primary care in terms of how they deliver new physical treatments and investigate these patients. This may be overcome by setting up in-house clinics run by specialist nurses.

What patients want is a sympathetic interview with a clear explanation of the problem and expert advice about self-administered treatments. This condition has serious adverse effects on the quality of life and to address the problem doctors need to be able to discuss sexual matters with their patients.

It should not be forgotten that this problem affects not only the men but also their partners, and ED can lead to considerable marital disharmony. Primary care physicians can be supportive by providing accurate, unbiased and realistic information for men and their partners. This can help to counter the effect of this disability and help to dispel the inaccurate and misleading information that patients have so often received through the media and friends and family.

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