Erectile Dysfunction

Erectile dysfunction (ED) prescribing guidelines in primary care for adults aged 18 years and above.

Key messages

  • Lifestyle changes should be discussed, and psychosexual causes explored before pharmacological treatments are considered for ED. Management of comorbidities should be optimised (e.g. diabetes, cardiovascular disease).
  • ED may represent an early marker of cardiovascular disease and should prompt cardiovascular risk assessment, where appropriate.
  • Consider whether the patient may be suffering from medication-induced ED (see section on drugs which can cause ED).
  • Consider hypogonadism assessment particularly in men with low libido, fatigue, reduced morning erections, metabolic syndrome, diabetes, or poor phosphodiesterase-5 (PDE-5) response.
  • Phosphodiesterase-5 (PDE-5) inhibitors have no effect in the treatment of ED in the absence of sexual stimulation.
  • Prescribe generic sildenafil(as required frequency). If treatment with sildenafil is not tolerated/ ineffective/contraindicated prescribe generic tadalafil (when required frequency) as the first choice oral PDE-5 inhibitors for ED.
  • Historically PDE-5 inhibitors were prescribed as one treatment dose per week on the NHS. However, for men who prefer spontaneous (rather than planned) sexual activity, or who anticipate frequent sexual activity (at least twice a week), daily tadalafil 5mg can be considered (see section on quantity).
  • If a patient cannot tolerate tadalafil 5 mg once daily, they should be switched back to a when required regimen (sildenafil or tadalafil). Splitting tablets is unlicensed and is not advised. Tadalafil 2.5mg tablets are non-formularyacross SWL.
  • Advise patients on the availability of Over the Counter (OTC) sildenafil and tadalafil products to purchase from pharmacies.
    • ED medications are amongst the most counterfeited medicines in Europe.
  • Review the prescribing of PDE-5 inhibitors for the treatment of ED:
    • Arrange follow-up 6 to 8 weeks after initiation of treatment to assess the efficacy and safety of the treatment as well as patient satisfaction.
    • Patients prescribed other PDE-5 inhibitors should be reviewed to replace treatment with generic sildenafil or tadalafil where appropriate.
  • Change existing patients prescribed Cialis® to generic tadalafil 5mg once daily, 10mg or 20mg as required (Cialis® is on average 33 times more expensive than generic tadalafil).
  • Generic sildenafil and generic tadalafil may be prescribed on NHS FP10 in line with SWL formulary guidance for all patients with ED. All other oral PDE-5 inhibitors (avanafil and vardenafil) are non-formulary across NHS SWL.
  • For information on contraindications, cautions, dosing information and side effects please refer to the Summary of Product Characteristics (SPC) or British National Formulary (BNF).
  • A patient with ED should receive 4 to 8 doses of a PDE-5 inhibitor with sexual stimulation at a maximum dose before being classified as a non-responder or oral treatment deemed ineffective.
  • If failed response to two oral PDE-5 inhibitors, refer to the section on alternative treatment options (specialist recommendation only).

Erectile Dysfunction pathway

The ED treatment pathway is also available as a visual summary flow chart.

Confirm diagnosis of Erectile Dysfunction in adults aged 18 years and above

  • Assess for causative factors, offer lifestyle advice and assess cardiac risk.
  • Management of comorbidities should be optimised.

Prescribe generic sildenafil or tadalafil on FP10

  • Usual starting dose of sildenafil is 50mg as required, increasing to 100mg if ineffective or decreasing to 25mg, where clinically appropriate.
  • If treatment with sildenafil is not tolerated or is ineffective or is contraindicated, prescribe generic tadalafil (as required frequency).
  • Usual starting dose of tadalafil is 10mg as required, increasing to 20mg if ineffective. For men who prefer spontaneous (rather than planned) sexual activity, or who anticipate frequent sexual activity (at least twice a week), daily tadalafil 5mg can be considered.
  • Refer to SPC for full dosing information, contraindications, and drug interactions.
  • Advice on recommended quantity to supply can be found in the section on quantity.

Follow up treatment 6 to 8 weeks after initiation

  • If treatment is tolerated and effective (a patient should receive 4 to 8 doses of a PDE-5 inhibitor at a maximum tolerated dose with sexual stimulation before treatment is classified as non-effective), continue with treatment on an FP10.
  • Note, all treatments for ED (except generic sildenafil and generic tadalafil) require an SLS endorsement to be prescribed on the NHS (see section on SLS).
  • A patient should trial at least two different PDE-5 inhibitors taken sequentially before being classed as a ‘non-responder’ (trialing each PDE-5 inhibitor for 4 to 8 doses at a maximum tolerated dose with sexual stimulation before switching to an alternative drug).

If treatment failure on 2 oral PDE-5 inhibitors

  • Consider alternative therapy options on FP10 only if patient meets SLS criteria (specialist recommendation only). If not offer private prescriptions for alternative ED treatments.

Topical preparations:

Topical preparations have an Amber 1 prescribing status i.e. Primary care initiation, on the recommendation of a specialist.

Alprostadil transurethral application:

  • MUSE® urethral sticks
    • Vitaros® cream

Vacuum erectile dysfunction pump:

Vacuum erectile dysfunction pumps are Amber 1 prescribing status i.e. Primary care initiation, on the recommendation of a specialist.

  • Initial pump training to be provided to the patient by the Acute Trust recommending the device. Training is provided by the supplier.
  • Specialist recommending the initiation of the device must communicate clearly, in writing, to the patient’s GP what product is to be prescribed.
  • Only devices included in the Drug Tariff are to be recommended for patients fulfilling SLS criteria (see section on SLS).
  • Patients who do not fulfil the SLS criteria will have to purchase the device privately.

Injectable preparations

These are Amber 2 prescribing status i.e. Secondary care initiation with continuation in primary care (or via specialist primary care services, where available).

  • Injectable devices are to be initiated and supplied in secondary care. GPs can continue prescribing in primary care if treatment is deemed effective after one month.
  • Initial sharps bin is provided by secondary care; ongoing sharps bins can be provided in the community.
  • Alprostadil intracavernosal injection:
    • Caverject® Dual Chamber: 10 and 20 microgram injections
    • Viridal Duo®: 10, 20 and 40 microgram injections
  • Aviptadil with phentolamine mesylate is reserved for patients who cannot use intracavernosal alprostadil due to pain, or supply issues or no response from 40mcg alprostadil:
    • Invicorp®: 25micrograms/2mg/0.35ml solution for injection ampoules

Prescribing information

NHS SWL supports the prescribing of the following oral PDE-5 inhibitors for ED only:

  • Generic sildenafil 50mg as required (based on efficacy and tolerability, the dose may be increased to 100mg or decreased to 25mg).
  • Generic tadalafil 10mg as required (based on efficacy and tolerability, this can be increased to the maximum dose of 20mg).
  • Generic tadalafil 5mg daily for men who prefer spontaneous (rather than planned) sexual activity, or who anticipate frequent sexual activity (at least twice a week).
  • Change existing patients prescribed Cialis® to generic tadalafil 5mg once daily, 10mg or 20mg as required (Cialis® is on average 33 times more expensive than generic tadalafil).
  • If a patient cannot tolerate tadalafil 5 mg once daily, they should be switched back to as when required regimen (sildenafil or tadalafil). Splitting tablets is unlicensed and is not advised. Tadalafil 2.5mg tablets are non-formulary across SWL.
  • Branded sildenafil (Viagra®) and tadalafil (Cialis®) can only be prescribed on the NHS if the patient fulfils SLS criteria (see section on SLS)
  • All other oral PDE-5 inhibitors (avanafil and vardenafil) are non-formularyin SWL.

Refer to a specialist if treatment failure on 2 different oral PDE-5 inhibitors for consideration of alternative treatment options (a patient should trial at least two different PDE-5 inhibitors taken sequentially before being classed as a ‘non-responder’. Each PDE-5 inhibitor should be trialed for 4 to 8 doses at a maximum tolerated dose with sexual stimulation before switching to an alternative drug).

Selected List Scheme (SLS)

Prescribing of drugs for ED is restricted nationally under the SLS on the grounds of cost to the NHS except generic sildenafil and tadalafil. If a patient has any of the following conditions, they fulfil SLS criteria and can be treated for ED on an NHS prescription:

  • Diabetes, multiple sclerosis, Parkinson’s disease, poliomyelitis, prostate cancer, severe pelvic injury, single gene neurological disorder, spina bifida, spinal cord injury, receiving treatment for renal failure by dialysis, a man who has had the following surgery – prostatectomy, radical pelvic surgery or renal failure treated by transplant.
  • All treatments for ED (except generic sildenafil and generic tadalafil) require an SLS endorsement to be prescribed on the NHS.
  • Offer a private prescription if the patient does not respond to both generic sildenafil and generic tadalafil and does not fulfil SLS criteria .

For further information on SLS, refer to Part XVIIIB of the Drug Tariff.

Private prescriptions

  • Note: Generic sildenafil and generic tadalafil must not be prescribed privately for any NHS patient using it for ED.
  • Other ED medication cannot be prescribed privately for NHS patients with ED that fulfil SLS criteria.
  • Branded PDE-5 inhibitors can be prescribed privately for patients that do notfulfil the SLS criteria.

Quantity

All patients should be offered a trial of 4 doses of a PDE-5 inhibitor unless contraindicated.

  • Historically, NHS prescribing quantities for ED treatments were based on approximately one treatment dose weekly; however, prescribing should ultimately be guided by individual clinical need and clinician judgement.
  • Prescribers should be aware of the risks of excessive prescribing which can lead to unlicensed and unauthorised diversion of supply (PDE-5 inhibitors have “street value”) and/or possible dangerous use.

  • If a patient prefers spontaneous (rather than planned) sexual activity, or who anticipates frequent sexual activity (at least twice a week), daily tadalafil 5mg can be considered.

Daily Tadalafil

  • Daily tadalafil 5mg can be considered for men who prefer spontaneous (rather than planned) sexual activity, or who anticipate sexual activity at least twice weekly.
  • If a patient cannot tolerate tadalafil 5 mg once daily, they should be switched back to as required regimen (sildenafil or tadalafil). Splitting tablets is unlicensed use and is not advised. Tadalafil 2.5mg tablets are non-formulary across SWL.

Contraindications, Cautions, Drug Interactions and Adverse Effects

This section is not exhaustive. Refer to the individual SPC for full list of contraindications, cautions and drug interaction.

Contraindications

Do not prescribe a PDE-5 inhibitor to patients with any of the following co-morbidities

  • Hypotension (systolic Blood Pressure (BP) less than 90 mmHg)
    • History of non-arteritic anterior ischaemic optic neuropathy (NAION)
    • Recent Myocardial Infarction (MI within past 90 days)
    • Recent stroke (within past 6 months)
    • Severe or unstable heart disease (vasodilation or sexual activity  not recommended)
    • Taking nitrate medications
    • Unstable angina or angina during sexual intercourse
    • Hereditary degenerative retinal disorders (sildenafil only)
    • Severe hepatic impairment (sildenafil only)
    • New York Heart Association (NYHA) class II or greater heart failure (within the last 6 months) (tadalafil only)
    • Uncontrolled arrhythmias (tadalafil only)
    • Uncontrolled hypertension (tadalafil only)

Cautions

Prescribe a PDE-5 inhibitor, with caution,to a patient with any of the following co-morbidities:

  • Cardiovascular disease. Consider the potential cardiac risk of sexual activity in men with pre-existing cardiovascular disease before prescribing a PDE-5 inhibitor. Refer to NICE CKS Cardiac risk stratification section for further information.
  • Left ventricular outflow obstruction (for example aortic stenosis and idiopathic hypertrophic subaortic stenosis).
  • Anatomical deformation of the penis (for example angulation, cavernosal fibrosis, or Peyronie’s disease).
  • A predisposition to priapism (for example in sickle-cell disease, multiple myeloma, or leukaemia).
  • Prescribe sildenafil with caution to men with active peptic ulceration or bleeding disorders.

Drug interactions

Most common drug interactions

  • Nitrates: GTN, isosorbide mononitrate, or isosorbide dinitrate, nicorandil, or amyl nitrate (‘poppers’ used for recreation) are absolutely contraindicated.
  • Alpha-blockers: can increase the risk of postural hypotension as both are vasodilators.
  • Cytochrome P450 (CYP) 3A4 and 2C9 inhibitors (e.g. ritonavir, ketoconazole, itraconazole, erythromycin, cimetidine, and grapefruit juice): co-administration should be avoided if possible.
  • CYP3A4 inducers (e.g. rifampicin, phenobarbital, phenytoin, and carbamazepine): co-administration should be avoided if possible.
  • Sacubitril/valsartan: prescribe sildenafil with caution due to significant drop in blood pressure.

Common adverse effects

  • Back pain, dizziness, dyspepsia, flushing, migraine, myalgia, nasal congestion, nausea, and vomiting.

Drugs which can cause ED

  • Diuretics: Thiazides (for example bendroflumethiazide), spironolactone.
  • Antihypertensives: Methyldopa, clonidine, beta-blockers (for example propranolol), verapamil.
  • Fibrates: fenofibrate, gemfibrozil.
  • Antipsychotics: Phenothiazines (for example chlorpromazine), butyrophenones (for example haloperidol).
  • Antidepressants: Tricyclic antidepressants (e.g. amitriptyline), monamine-oxidase inhibitors (MAOI) (e.g. phenelzine), selective serotonin reuptake inhibitor (SSRI) (e.g. fluoxetine), lithium
  • Hormones: Oestrogens, progesterone, corticosteroids, cyproterone acetate, 5-alpha reductase inhibitors (e.g. finasteride)
  • Cytotoxics: Cyclophosphamide, methotrexate
  • Recreational drugs: Alcohol, tobacco, cannabis
  • Histamine antagonists: Cimetidine, ranitidine
  • Anti-arrhythmics and anticonvulsants: Disopyramide, carbamazepine

Patient advice

Around 30 to 35% of men fail to respond to initial treatment with PDE-5 inhibitors largely due to inadequate counselling and unrealistic expectations. Therefore, advise patients of the following:

  • ED usually responds well to a combination of lifestyle changes and drug treatment.
  • Lifestyle changes include (where applicable) losing weight, reducing stress, stopping smoking, reducing alcohol consumption, stopping illicit drug use and increasing exercise.
  • Counsel patients on possible side effects including headache, flushing (common), visual disturbance, and priapism (very rare).
  • Advise patients to not stop taking prescribed medication unless instructed to by a healthcare professional.
  • Advise patients not to take unlicensed herbal remedies for ED. They could contain prescription-only medicines which may be contraindicated or interact with prescribed medication.
  • Advise patients that there is a delay in onset of action with PDE-5 inhibitors and sexual stimulation is required.

Sildenafil

  • To be taken 1 hour before sexual activity.
  • Takes 30 to120 minutes (median 60 minutes) to reach maximum plasma concentration.
  • Takes 25 minutes (range 12 to 37 minutes) to cause an erection.
  • Patients should still be able produce an erection 4 to 5 hours post dose.
  • Rate of absorption is reduced by an average of 60 minutes when consumed with food.

Tadalafil

  • To be taken at least 30 minutes before sexual activity.
  • Takes 2 hours (median) to reach maximum plasma concentration.
  • Erectile response may occur from approximately 16 minutes after dosing in some patients, and efficacy may persist for up to 36 hours.
  • Rate of absorption is not affected by food intake.

Cycling

  • If cycling more than 3 hours a week, advise patients to try a period of time without cycling.
  • If it is not possible for them to stop cycling, preventative measures, such as the use of a properly fitted, well-padded bicycle seat and riding with the seat in a suitable position, may help prevent impairment of erectile function.

Alternative treatment options if failed response to 2 oral PDE-5 inhibitors (specialist recommendation only)

Topical preparations, injectable devices and Vacuum pumps are alternatives to oral PDE-5 inhibitors for the treatment of ED. Patients should be assessed for suitability for these products by a specialist. Patients and their partners must be counselled appropriately to ensure they can use the treatment effectively to maximise concordance, efficacy of treatment and patient satisfaction with treatment.

Alprostadil

  • The combination of alprostadil with other ED agents is not approved nor recommended
  • Alprostadil can only be provided on the NHS for patients who fulfil NHS SLS criteria (see section on SLS).
  • All products listed below require SLS endorsement on an NHS prescription.

Topical formulary preparations (Amber 1):

This is a better option for patients on medications that may increase bleeding risk. They can be initiated in primary care under the advice of a specialist.

  • MUSE®
    • Intraurethral application
    • 30 to 60% efficacy (refer to individual SPC for more information).
  • Vitaros®
    • Topical cream.
    • 31 to 40% efficacy (refer to individual SPC for more information).

Intracavernous injection formulary preparations (Amber 2):

  • Caution should be advised in patients receiving concomitant medications, which could increase the risk of bleeding, such as anticoagulants or platelet aggregation inhibitors.
  • Injectable devices are to be initiated and supplied in secondary care. GPs can continue prescribing in primary care if treatment is deemed effective after one month. Initial sharps bin to be provided by secondary care, ongoing sharps bins can be provided in the community. Intracavernous alprostadil has 70 to 80% efficacy (refer to individual SPCs for more information).
  • Viridal Duo®
    • Preferred product over Caverject® Dual Chamber (DC) for patients requiring a 40mcg dose as it is more user friendly.
    • Patient can inject 1x40mcg Viridal® Duo injection compared to having to inject 2x20mcg Caverject® DC (Caverject® DC is not available in a 40mcg strength).
    • Prescribing 1×40 mcg Viridal® Duo is more cost effective than 2x20mcg Caverject® DC.
  • Caverject® Dual chamber
    • Note: Caverject® (alprostadil) powder for solution for injection vials is non formulary. It should not be initiated for new patients. It is only to be used for existing patients across SWL.

Aviptadil with phentolamine mesylate

  • Second line injectable option for ED.
  • Reserved for patients who cannot use intracavernosal alprostadil due to pain or supply issues or no response from 40mcg alprostadil.
  • Not to be initiated in primary care, for continuation only after recommendation and initiation by a specialist.
  • Invicorp®
    • 25micrograms/2mg/0.35ml solution for injection ampoules.

Vacuum erectile dysfunction (VED) pump:

  • VED pumps are only to be prescribed by a GP based on a specialist recommendation following patient assessment and training.
  • VEDs are contraindicated in men with bleeding disorders or those taking anti-coagulant therapy.
  • These should only be prescribed for patients fulfilling SLS criteria. Patients who do not fulfil the criteria will have to purchase privately (see section on SLS).

References/resources

Version 4.2 approved by Integrated Medicines Optimisation Committee (IMOC) August 2026.