Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body's normal response is to increase blood flow to his penis to produce an erection. By controlling the enzyme, Sildenafil helps to maintain an erection after the penis is stroked. Without physical action to the penis, such as that occurring during sexual intercourse, Sildenafil will not work to cause an erection.
Sildenafil belongs to a group of medications that are known as ‘PDE-5 inhibitors’. They work by relaxing the blood vessels in your penis, which increases blood flow to the area and helps you get an erection. It will not help you get an erection if you are not sexually aroused. The treatment will not resolve the underlying physical cause of your ED or increase your sexual desire.
Sildenafil treats ED in around two thirds of cases. Sildenafil starts working around 30 to 60 mins after you take it. It normally lasts around 4 to 6 hours. It should be tried at least 8 times before giving up, considering a higher dose, or seeking an alternative.
severity of your ED, you may be prescribed a lower dose of 25mg, or a higher one of 100mg. Dosage does not affect how quickly or for how long the treatment works. We recommend that you try the 50mg tablet first to see whether this has the desired effect. Higher doses come with an increased chance of developing side effects.
Generally Sildenafil requires 30-60 minutes to take effect, therefore it should be taken at least one hour before you intend to have sex. It should be taken orally on an empty stomach. The effects of Sildenafil last between 4-6 hours; it should not be taken too early before sex because the effects can wear off. Sildenafil requires arousal and sexual stimulation to take effect. It won’t give you an erection on its own.
You should always start with a low initial dose. If, after you have tried it 4 times, you feel that a stronger dose will work better then you should try the next strength up. However, this must only be done if you are not experiencing any side effects as these will only be exacerbated with a stronger dose.
Never take more than one Sildenafil tablet at a time or in combination with any other erectile dysfunction medication. Nor should the medication be taken more than once in a 24-hour period.
Sildenafil can be taken after eating or on an empty stomach. However, if you take Sildenafil after a high-fat meal (e.g. fried food) you might find it takes longer to feel an effect. Drinking more than one or two units of alcohol will make Sildenafil less effective. Excessive alcohol can compromise erections regardless of erectile dysfunction.
Always use this medication exactly as your clinician has told you. Check with our clinical team or your GP or pharmacist if you are not sure.
Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
Sildenafil has been used by millions of men worldwide for over a decade and has been proven to be a safe and effective treatment for erectile dysfunction. For the majority of users no side effects are experienced. However, some men may experience mild side effects and less than 1% will experience serious side effects.
Side effects are uncommon but can include:
- Nausea
- Vomiting
- Back pain
- Diarrhoea
- Allergic rash
- Facial flushing
- Headaches
- Light headedness
- Nasal congestion
- Indigestion
- Palpitations (racing heartbeat)
- Blurred vision
For full information on side effects and correct use, see the patient information leaflet. If any side effects concern you, or you are experiencing any of the side effects mentioned in the patient information leaflet whilst taking this medication, please contact our clinical team or speak to your GP.
Be aware that sexual activity carries a possible risk to patients with heart disease because it puts an extra strain on your heart. If you have a heart problem you should inform our clinical team.
Sildenafil is not suitable if you are taking nicorandil or nitrates, such as GTN spray or isosorbide mononitrate tablets to treat angina.
There are other situations where you shouldn’t take Sildenafil, including if:
- You suffer from heart disease or heart rhythm problems
- You have had a heart attack or stroke within the last six months
- You have high or low blood pressure
- You suffer from liver or kidney disease
- You are a haemophiliac
- You suffer from sickle cell anaemia or leukaemia
- There is a physical deformity of the penis
- You suffer from retinitis pigmentosa
- You have a stomach ulcer.
Get emergency medical help if you have signs of an allergic reaction to this medication. These include:
- Hives
- Dizziness
- Fast or pounding heartbeats
- Wheezing
- Difficult breathing
- Swelling of your face, lips, tongue, or throat.
It is important that you let us know which prescription, over-the-counter medicines and recreational drugs you are currently taking. You must also tell us about any other medical conditions that you currently have (or had in the past). This will help us ensure the prescribed medication is safe and appropriate for you to take.
For full information on warnings, medication interactions and contraindications, refer to the Patient Information Leaflet. Please read all packaging and the Patient Information Leaflet before taking any new medicine and inform our clinical team or your GP of medicines you are taking or intend to take.
