1. View erectile dysfunction as a symptom rather than a diagnosis
Multiple large studies have consistently demonstrated that ED is a common problem estimated to affect up to 50% of men over the age of 40, the prevalence increasing with age. Despite this the proportion of patients with ED seeking medical advice is low. However, when a patient does mention it, even in passing, it should alert the GP to potential significant underlying pathology. Erections are the result of an interaction between neurogenic, vasogenic, hormonal and psychogenic mechanisms, and ED can be an indication of significant problems in one or more of these systems, which may require further investigation.
2. Confirm the patient actually has ED
Ensure that the patient’s complaint is ED, i.e. the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual performance. Occasionally, patients with other pathologies, such as Peyronie’s disease or ejaculatory disorders, will complain of ED or ‘impotence’. It is important to take a thorough sexual history and to enquire about the impact not only on the patient’s wellbeing, but also on their partner’s. It is often helpful if they both are present at the consultation so you can explore any obvious physical and psychological problems the couple might have.
3. Consider ED as a sign of cardiovascular disease until proven otherwise
Even mild ED is an independent risk factor for cardiovascular disease (CVD). A thorough cardiovascular risk assessment is essential in all men presenting with ED, including identifying risk factors such as smoking, obesity, poor diabetic control and undiagnosed diabetes, which are common to both conditions and are modifiable. Ensure you check the blood pressure and record the BMI. Measurement of serum lipids and HbA1c are an essential part of the baseline investigations.
4. Don’t forget to ask about symptoms that may suggest low testosterone
ED may be the presenting symptom of hypogonadism. Common symptoms include fatigue, depression/low mood, weakness and poor libido. In the presence of these symptoms, combined with biochemical evidence of low testosterone, androgen replacement therapy may prove beneficial, including treating ED. Even if the ED does not resolve, there is evidence that the patients will have a better response to PDE5 inhibitors if their testosterone is within the normal range. Biochemical evidence of low testosterone should prompt measurement of prolactin and luteinising hormone levels.
5. Look for recent changes to medications that may correlate with onset of erectile problems
Many commonly prescribed medications have an association with ED. The list of pharmacological agents associated with ED is extensive, but common culprits include diuretics, antihypertensives (particularly beta-blockers), antipsychotics and antidepressants, as well as drugs to treat benign prostatic hyperplasia (BPH) and prostate cancer. An enquiry into recreational drug use may reveal excessive alcohol intake, which is associated with ED and hypogonadism, as are most illicit substances.
6. Treat modifiable factors and underlying conditions
Encourage patients to adopt lifestyle modifications such as smoking cessation, weight loss, reducing alcohol and increased exercise. Treat/optimise the management of any associated conditions that could be contributing to the ED. Stopping medications implicated as a cause of ED may be helpful but only if a suitable alternative is available as suboptimal management of any underlying condition may cause more harm to erectile function in the long run, as well as the patients general health. There is some evidence that prolonged cycling may result in ED, and in keen cyclists a trial off the bike may be beneficial or one could suggest modifying position or saddle.
7. PDE5 inhibitors are the first-line treatment
Available data suggests that over 80% of men will respond to PDE5 inhibitors. There are currently four PDE5 inhibitors available – sildenafil, tadalafil, vardenafil and avanafil. Each has different characteristics, speed of onset, half-lives and side-effect profiles. Common reasons for failure include inadequate dosing, mistiming doses, lack of sexual stimulation or lack of efficacy. For example, the onset of action of sildenafil may take up to 60 minutes, whereas for tadalafil it may take up to two hours, and the onset of action of the former but not the latter is delayed if taken with a full stomach. Equally a delay in sexual stimulation may result in failure more so for sildenafil and vardenafil, which have half-lives of around for hours, unlike tadalafil which is 17.5 hours.
There is evidence that patient education about these issues will produce a satisfactory result in some men who initially fail to respond. In those who are still unsuccessful, a trial of a second PDE5 inhibitor may be beneficial in a small proportion and is recommended. If two PDE5 inhibitors have failed, it is unlikely that a third will be successful. Cost-wise, sildenafil is significantly cheaper and free from prescribing regulations. Although NHS guidelines suggest that we should prescribe a maximum of one tablet per week, the maximum dose is once per 24 hours
8. Caution in men with high risk cardiovascular disease
There is no evidence that sexual activity or substances used in the management of ED increase the risk of cardiac disease, and initiation of management (for example, with PDE5 inhibitors) does not need to be deferred in those who have low or moderate risk disease. But in those with high risk disease – recent cardiac event, unstable angina, congestive heart failure NYHA groups 3 and 4, moderate to severe valve disease and uncontrolled dysrhythmias – sexual activity carries significant risk (it is the equivalent of briskly climbing two flights of stairs or a one mile walk). In these patients, management should be deferred until their cardiac disease is optimally controlled and their risk improves.
All PDE5 inhibitors are contraindicated in patients with severe cardiovascular disease or patients using nitrates. Patients who use their sublingual spray infrequently and who are not in the high risk category for their cardiovascular disease could consider PDE5 inhibitors, but their nitrates must not be used for 24-48 hours afterwards (depending on PDE5 type), and if angina pain occurs within this time then alternative therapy must be used. This risk needs to be carefully considered and discussed with the patient beforehand.
9. Consider PDE5 inhibitors for men with ED and lower urinary tract symptoms (LUTS)
Bladder outflow obstruction due to BPH resulting in LUTS is increasingly common with increasing age and is associated with a concomitant reduction in erectile function. Studies suggest tadalafil 5mg once daily has similar efficacy to tamsulosin 400mcg once daily in improving LUTS, but with the additional benefit of treating ED. It is now licensed for men with BPH LUTS who also have ED. This has cost implications but may be an option for some men. It’s worth noting that some PDE5 inhibitors are contraindicated with some α-blockers,e.g. tadalafil is contraindicated in men taking doxazosin (although not tamsulosin)-check the product literature for specific details.
10. Refer after trying two different PDE5 inhibitors
In general most men with ED will require ongoing therapy. Exceptions include those with psychogenic, hormonal or traumatic ED which may be cured by addressing the underlying aetiology. Men who have been thoroughly assessed in primary care, treated for associated conditions and failed lifestyle modification, and treated with two different PDE5 inhibitors at maximum dose, should be offered referral to secondary care. Further management options that the patient may be offered include a vacuum pump or intraurethral, topical or intracavernosal alprostadil. If these measures fail and in men who are motivated and are willing to accept a significantly more invasive therapy, a penile prosthesis can be considered, although they are not always funded by the NHS and each case is considered on a case by case basis.
Mr Christopher Dowson is a specialist registrar in urology, and Mr Michael Foster is a consultant urological surgeon, both based at the Heart of England NHS Foundation Trust, Birmingham
Hackett G, Kell P, Ralph D et al. British Society for Sexual Medicine guidelines on the management of erectile dysfunction. J Sex Med, 2008;5:1841-1865
Hatzimouratidis K, Amar E, Eardley I et al. Guidelines on male sexual dysfunction: erectile dysfunction and premature ejaculation. Eur Urol, 2010;57:804-814
NICE. Clinical knowledge summary: erectile dysfunction. London: NICE; 2014