7.4.5 Drugs for erectile dysfunction

General Notes

• Drug treatments for erectile dysfunction may only be prescribed on the Health Service under certain circumstances. These are:
  • men who have diabetes, multiple sclerosis, Parkinson’s disease, poliomyelitis, prostate cancer, severe pelvic injury, single gene neurological disease, spina bifida, or spinal cord injury
  • men who are receiving dialysis for renal failure
  • men who have had radical pelvic surgery, prostatectomy (including transurethral resection of the prostate) or kidney transplant
  • men who were receiving Caverject^®, Erecnos^®, MUSE^®, Viagra^® or Viridal^® for erectile dysfunction, at the expense of the NHS, on 14^th Sept 1998
• The prescription must be endorsed “SLS”.
• GPs can issue private prescriptions for patients on their list, that don’t meet SLS criteria (but cannot charge patients for a private appointment in this instance).
• Men suffering from severe distress as a result of impotence should be referred for assessment by specialist in secondary care. In Northern Ireland, treatments for impotence leading to severe distress are classified as red drugs; supply is via hospital pharmacies. For full details on the red/amber list, visit http://www.ipnsm.hscni.net/red-amber.

Prescribing Notes

• Presentation with erectile dysfunction should prompt assessment and screening for cardiovascular disease and diabetes.
• In the management of acute myocardial infarction, men should be specifically asked if they are taking drugs for erectile dysfunction.
  
• A medication review should be carried out as certain medicines can precipitate erectile dysfunction, e.g. antihypertensive drugs.
• Examination of the patient is important to check for anatomical abnormalities and Peyronie’s disease which may need referral to urology.
• Erectile dysfunction usually responds well to a combination of lifestyle changes and drug treatment. Advise, where applicable, that he should lose weight , stop smoking, reduce alcohol consumption, and increase exercise.
• Provided there are no contraindications, phosphodiesterase-5 (PDE-5) inhibitors are currently recommended as first-line treatment for erectile dysfunction.
• Sildenafil has a duration of action of about 4 hours; tadalafil may be a suitable alternative for patients where a longer duration of action is required (17.5 hours).
• There is not enough evidence to routinely recommend tadalafil ‘once daily’ (2.5mg, 5mg) preparations for erectile dysfunction, avoid prescribing.
• Sildenafil, tadalafil and vardenafil are contraindicated in men receiving nitrates in any form, and nicorandil. Consider discontinuing nitrates if no longer needed.
• Cardiovascular disease and multiple antihypertensive drug regimens are not contraindications to sildenafil or tadalafil therapy provided the man is capable of ordinary daily tasks (and therefore sexual activity) without cardiac symptoms.
• Sildenafil, tadalafil and vardenafil are not licensed for use with other treatments (drug and non-drug) for erectile dysfunction. Such use is therefore off-license and prescribers should ensure that they follow General Medical Council (GMC) advice on prescribing off-license. If patients require combination treatment, they should be referred to a Sexual Dysfunction Clinic.
• Sildenafil 50mg (Viagra^® Connect) is now available to purchase from pharmacies for suitable patients.

Other treatments

• Vacuum tumescence devices are an alternative treatment and a range of devices are available on NHS prescription, although they are usually initiated by a specialist. They may be a suitable option in well-informed older patients with co-morbidities and infrequent sexual intercourse requiring non-invasive, non-pharmacological treatment. They are contra–indicated in men receiving anticoagulant therapy.
• Intracavernosal, intraurethral or topical application of alprostadil is recommended as second-line therapy under careful medical supervision.