7.4.5 Drugs for erectile dysfunction
Drug treatments for erectile dysfunction may only be prescribed on the NHS under certain clinical conditions. These arrangements are explained in PCA(M)(1999)/PCA(P)(1993)3. The arrangements pertaining to patients suffering severe distress because of erectile dysfunction have been reviewed, for more information see the local agreement and PCA(M)(2011)4.
For information on the Management of erectile dysfunction in primary care see the Clinical Guidance Intranet.
Prescriptions must be endorsed 'SLS'.
Phosphodiesterase type 5 inhibitors
Sildenafil, tadalafil and vardenafil are phosphodiesterase type 5 inhibitors licensed for the treatment of erectile dysfunction. Tadalafil can be taken with or without food and has a longer duration of action (efficacy is maintained for up to 36 hours) than sildenafil (and vardenafil) and is primarily for patients for whom this represents a significant advantage. Vardenafil is used for diabetic patients and those who are unresponsive to sildenafil.
Sildenafil (25mg, 50mg 100mg tablets)
Dose (adults over 18 years): initially 50mg taken as needed approximately 1 hour before sexual activity, subsequent doses adjusted according to response to 25-100mg as a single dose as needed. Maximum 1 dose in 24 hours (max. single dose 100mg). Note: Onset of effect may be delayed if taken with food.
Tadalafil (2.5mg, 5mg, 10mg and 20mg tablets)
Dose (adults over 18 years):
On-demand regimen - initially 10mg taken as needed at least 30 minutes before sexual activity, subsequent doses adjusted according to response, up to 20mg as a single dose. Maximum 1 dose in 24 hours (continuous daily use of 10-20mg not recommended).
Once-daily regimen - in patients who have responded to 'on-demand tadalafil' and anticipate frequent use (at least twice weekly) a once-daily regimen with the lowest doses of tadalafil (2.5mg and 5mg) might be considered. Dose: 5mg taken once a day at approximately the same time of day, reduced to 2.5mg once daily according to individual tolerability/response. Continued use of the daily regimen should be reassessed periodically.
Note: Sexually active patients who have recently undergone a prostatectomy may be prescribed low dose tadalafil on alternate days as a long-term rehabilitation treatment. This should only be initiated under specialist supervision.
Vardenafil (5mg, 10mg, 20mg tablets)
Dose (adults over 18 years): initially 10mg taken as needed 25 to 60minutes before sexual activity, subsequent doses adjusted according to response to 5mg-20mg as a single dose as needed. Maximum 1 dose in 24 hours (max. single dose 20mg). Note: Onset of effect may be delayed if taken with a high fat meal.
Alprostadil (injection) is licensed for administration by intracavernosal injection in the treatment of erectile dysfunction. The first injection is supplied in hospital under the supervision of a consultant urologist. Following training and instruction, further supplies may be prescribed by the patient's general practitioner for self-injection at home. Alprostadil urethral stick (Muse®) is also available.