Drug Safety Update
November 2018: Sildenafil (Revatio and Viagra): reports of persistent pulmonary hypertension of the newborn (PPHN) following in-utero exposure in a clinical trial on intrauterine growth restriction
Some drug treatments for erectile dysfunction may only be prescribed on the NHS under certain circumstances; for details see the criteria listed in part XVIIIB of the Drug Tariff. NHS prescriptions (endorsed "SLS") can be issued for sildenafil, alprostadil, tadalafil, vardenafil and certain vacuum tumescence devices to men suffering from erectile dysfunction who have these medical conditions: diabetes, prostate cancer or prostatectomy, spinal cord injury, radical pelvic surgery or severe pelvic injury, Parkinson's disease, renal failure requiring dialysis or following transplant, multiple sclerosis, spina bifida, poliomyelitis, single gene neurological disease, plus men who were receiving treatment for erectile dysfunction at the expense of the NHS before 14th September 1998. GPs can issue private prescriptions for the above drugs and devices for patients on their list who do not meet these criteria, but cannot charge patients for issuing a private prescription.
The DoH has recommended that treatment should also be available from specialist services when the condition is causing severe distress and the following criteria should be assessed.
- significant disruption to normal social and occupational activities
- a marked effect on mood, behaviour, social and environmental awareness
- a marked effect on interpersonal relationships
Phosphodiesterase 5 (PDE5) inhibitors increase arterial blood flow, which leads to smooth muscle relaxation, vasodilation and penile erection. Three potent selective PDE5 inhibitors - sildenafil (Viagra®), tadalafil (Cialis®) and vardenafil (Levitra®) are available. These medications have proven efficacy and safety both in non-selected populations of men with ED and in specific sub-groups of patients, (for example, men with diabetes and those who have had a prostatectomy). The major difference in these drugs is that sildenafil and vardenafil are relatively short-acting drugs, having a half-life of approximately 4 hours, whereas tadalafil has a significantly longer half-life of 17.5 hours.
Sildenafil is also licensed to treat pulmonary hypertension (initiated under specialist supervision).
Tadalafil may be prescribed to be taken regularly post prostatectomy to help restore function. This is an unlicensed indication and must be prescribed on specialist advice.