- Treatment for erectile dysfunction with sildenafil
- Access sildenafil following an online medical consultation
- What is sildenafil?
- What is the active substance in sildenafil?
- Who may be considered for treatment with sildenafil?
- What dosages are available?
- How is sildenafil taken?
- When should sildenafil not be used?
- Warnings and precautions
- Possible side effects
- Use with alcohol and food
- Driving and operating machinery
- Storage information
- Active substance and excipients
- Sildenafil patient information leaflet
Treatment for erectile dysfunction with sildenafil
Sildenafil is a prescription-only medicine used in adult men for the treatment of erectile dysfunction. Erectile dysfunction is defined as the persistent inability to achieve or maintain an erection sufficient for satisfactory sexual activity.
Sildenafil belongs to a group of medicines known as phosphodiesterase type-5 (PDE-5) inhibitors. It works by increasing blood flow to the penis during sexual stimulation, which can help achieve and maintain an erection.
The tablets are available in different strengths. The dose prescribed depends on individual health factors and response to treatment, and must be determined by a clinician following a medical assessment.
Access sildenafil following an online medical consultation
Start the online consultation and complete a confidential medical questionnaire.
A UK-registered healthcare professional will review your information and determine whether sildenafil may be appropriate. If suitable, a prescription can be issued following clinical assessment.
Important information
DoktorABC UK is a digital health platform that connects patients with independent, UK-registered healthcare professionals. DoktorABC UK does not provide medical care, issue prescriptions or dispense medicines. All clinical decisions are made by the prescribing clinician following an individual medical assessment.
What is sildenafil?
Sildenafil is a medicine used to treat erectile dysfunction in adult men. The active substance works by relaxing blood vessels in the penis, allowing increased blood flow during sexual stimulation.
Sildenafil does not cause an erection on its own. Sexual arousal is required for the medicine to be effective.
The onset of action is typically between 30 and 60 minutes after taking the tablet. The effects may last for up to 4–5 hours, although this varies between individuals.
What is the active substance in sildenafil?
The active substance is sildenafil citrate. It inhibits the PDE-5 enzyme, which plays a role in regulating blood flow in the penis.
By inhibiting this enzyme, sildenafil enhances the natural erectile response to sexual stimulation. Suitability depends on overall health, current medicines and cardiovascular status.
Who may be considered for treatment with sildenafil?
Sildenafil may be considered for adult men (aged 18 and over) who experience erectile dysfunction, following a medical assessment.
Treatment may not be suitable for everyone. A clinician will assess:
- Cardiovascular health
- Current medicines
- Underlying medical conditions
What dosages are available?
Sildenafil is commonly prescribed in the following strengths:
- 25 mg
- 50 mg
- 100 mg
The usual starting dose is 50 mg, taken when needed. The dose may be adjusted by the clinician depending on effectiveness and tolerability.
Sildenafil should not be taken more than once per day.
How is sildenafil taken?
Sildenafil should be taken approximately one hour before sexual activity.
The tablet should be swallowed whole with water.
It can be taken with or without food. However, a heavy or high-fat meal may delay the onset of effect.
When should sildenafil not be used?
Sildenafil must not be used if you:
- Are allergic to sildenafil or any of its ingredients
- Take nitrate medicines for chest pain (angina)
- Use nitric oxide donors (such as amyl nitrite, "poppers")
- Take riociguat
- Have severe heart or liver disease
- Have recently had a heart attack or stroke
- Have very low blood pressure
- Have certain rare inherited eye conditions or a history of sudden vision loss
Always inform your clinician about your full medical history before starting treatment.
Warnings and precautions
Before using sildenafil, speak to your clinician if you:
- Have heart problems
- Have kidney or liver impairment
- Have blood disorders such as sickle cell anaemia, leukaemia or multiple myeloma
- Have anatomical deformation of the penis or Peyronie's disease
- Have a stomach ulcer
- Have a bleeding disorder such as haemophilia
- Have a history of sudden vision loss
Sildenafil should not be used with other treatments for erectile dysfunction or with other PDE-5 inhibitors.
Possible side effects
Like all medicines, sildenafil can cause side effects, although not everyone experiences them.
Common side effects
- Headache (very common)
- Flushing
- Indigestion
- Nasal congestion
- Dizziness
- Visual disturbances (altered colour perception, blurred vision)
Serious side effects (seek urgent medical help)
- Chest pain
- Sudden loss of vision or hearing
- Prolonged or painful erection lasting more than 4 hours (priapism)
- Severe allergic reactions (sudden wheezing, breathing difficulties, swelling of eyelids, face, lips or throat)
- Severe skin reactions
- Seizures
In the UK, suspected side effects can be reported via the MHRA Yellow Card Scheme.
Use with alcohol and food
Excessive alcohol consumption may reduce the ability to achieve an erection and may increase the risk of side effects.
Moderate alcohol intake is advised.
Driving and operating machinery
Sildenafil may cause dizziness or visual disturbances. Do not drive or operate machinery if affected.
Storage information
Store sildenafil at room temperature and keep out of the sight and reach of children.
Do not use after the expiry date shown on the packaging.
Dispose of unused medicine safely. Do not dispose via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required.
Active substance and excipients
Active substance:
Sildenafil (as sildenafil citrate), available in 25 mg, 50 mg and 100 mg strengths
Other ingredients:
Tablet core:
Lactose monohydrate, microcrystalline cellulose (E 460), hydroxypropyl cellulose (E 464), croscarmellose sodium, sodium stearyl fumarate, highly dispersed silicon dioxide (E 551)
Film coating:
Indigo carmine (E 132 aluminium lake), medium-chain triglycerides, hypromellose (E 463), maltodextrin, polydextrose (E 1200), ponceau 4R (E 124 aluminium lake), talc (E 553b), titanium dioxide (E 171), glucose monohydrate, soya lecithin (E 322), potassium aluminium silicate / titanium dioxide pigment (E 555), carmellose sodium (E 466)
Manufacturer:
STADA Arzneimittel AG
Sildenafil patient information leaflet
Frequently asked questions
How long does sildenafil take to work?
Sildenafil usually starts working within 30–60 minutes. The time may vary depending on individual factors and whether it is taken with food.
Does sildenafil work without sexual stimulation?
No. Sexual stimulation is required for sildenafil to be effective.
Can I take sildenafil every day?
Sildenafil should not be taken more than once per day. Treatment should be taken only when needed, approximately one hour before sexual activity.
What should I do if sildenafil doesn't work?
If sildenafil does not produce the desired effect or the erection is not sufficient, speak to your clinician. The dose may need to be adjusted, or alternative treatment may be more suitable.
How long should sildenafil be used?
Duration of treatment depends on individual needs and should be reviewed regularly with a clinician.
Can I take sildenafil if I have high blood pressure?
Sildenafil may be suitable if high blood pressure is well controlled. However, if you take certain blood pressure medicines, particularly alpha blockers, inform your clinician as dose adjustment may be required.
What is the difference between sildenafil and Viagra®?
Sildenafil contains the same active substance as Viagra® and works in the same way. It is a generic medicine and may be available at a lower cost.
Leaflet info
The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine. It is written for patients and gives information about taking or using a medicine. It is possible that the leaflet in your medicine pack may differ from the PDF-version from this website because it may have been updated since your medicine was packaged or the medicine is from another brand.
