Warning
All men who present with erectile dysfunction (ED) should undergo cardiovascular risk assessment and have serum testosterone measured on an early morning blood sample.
Consider life-style advice, medication review and psycho-sexual counselling.

In the absence of abnormal clinical findings, a trial of phosphodiesterase inhibitors is appropriate. Tadalafil and Sildenafil are currently on the Highland Formulary:

Tadalafil 10mg initially with titration up to 20mg according to the patient’s response. Take at least 30 minutes before intercourse and can be effective for up to 30 hours. Not affected by food.

Sildenafil 50mg initially with titration up to 100mg or down to 25mg according to the patient’s response. Take 1 hour before intercourse and can be effective for up to 6 hours. Onset of effect may be delayed by food.

Note: Sildenafil and Tadalafil are contra-indicated in patients receiving nitrates and Nicorandil and should be used with caution in patients on alpha-blockers e.g. Doxazosin, Tamsulosin.  If prescribing after myocardial infarction/acute coronary syndrome, advise re-introduction at 1 month after cardiac event if patient is pain free and does not require nitrates or Nicorandil.

Both Tadalafil and Sildenafil should be tried at their maximum doses on several occasions before referring the patient to Urology for consideration of other therapies e.g. transurethral or intra-cavernosal Alprostadil or vacuum devices.

Due to low cost of generic preparations, it is generally now longer the case that daily Tadalafil is more cost effective if the patient anticipates frequent use. The advantage for daily dosing is really for spontaneity.

Prescribing on the NHS

Drug treatments for erectile dysfunction may only be prescribed on the NHS under certain circumstances and the prescription must be endorsed SLS (Selected List Scheme).

Government guidelines on the categories of patients eligible for treatment under the NHS are:

Diabetes mellitus, distress, ED prior to 14/09/98, multiple sclerosis, Parkinson’s disease, poliomyelitis, prostate cancer, prostatectomy, radical pelvic surgery, renal dialysis or transplant, severe pelvic injury, single gene neurological disease, spina bifida, spinal cord injury.

The following criteria should be considered when assessing distress:

  • significant disruption to normal social and occupational activities;
  • a marked effect on mood, behaviour, social and environmental awareness;
  • a marked effect on interpersonal relationships.

General Practitioners are in the best position to determine whether or not a patient is in ‘severe distress’ as a result of their ED and Urologists are unable to determine this but will in every circumstance ratify a GP’s assessment if a prescription is endorsed SLS.

Specific regimens may be suggested by urology specialists for certain groups of patients such as those following total prostatectomies.

Editorial Information

Last reviewed: 30/04/2021

Next review date: 30/04/2024

Author(s): Urology Department .

Version: 1.1

Approved By: TAM Subgroup of ADTC

Reviewer name(s): Dr I Wilson, Consultant Urologist.

Document Id: TAM411