Sildenafil

Sildenafil is a prescription medication used to treat erectile dysfunction (when you struggle to get or keep erections). It is the generic or unbranded form of Viagra, a well-known, branded erectile dysfunction medication. Sildenafil and Viagra work in exactly the same way because they both contain the active ingredient sildenafil citrate.

Sildenafil comes in the form of oral tablets and can be prescribed in various doses of 25mg, 50mg and 100mg tablets.

Sildenafil is primarily prescribed to treat erectile dysfunction. It may sometimes be prescribed for other conditions by specialists.

Sildenafil can help men achieve and maintain an erection because it is a PDE-5 inhibitor (phosphodiesterase type 5 inhibitor). PDE-5 inhibitors work by blocking the PDE-5 enzyme which causes blood vessels to get narrower. When you take sildenafil, it causes blood vessels in the penis to relax and widen, helping to improve blood flow to the area.

Here is is how sildenafil works, step-by-step:

1. PDE-5 causes the blood vessels to get narrower.
2. Taking sildenafil 1 hour before sex blocks PDE-5 from working.
3. Blood flow is improved, allowing you to get and maintain an erection when sexually aroused.

The effects of sildenafil can last for up to 4 to 6 hours depending on the dosage and your body’s metabolism. This means that if you are sexually aroused during this time-frame the medication should help you to achieve and maintain an erection.

However, how long sildenafil lasts will differ from person to person and depends on the dosage. Many find that the effects of sildenafil normally start to wear off after 2 to 3 hours.

Remember, while sildenafil can last for 4 to 6 hours, this does not mean that your erections will last this long when you take the medication. If you experience an erection lasting over 4 hours you should seek medical advice.

Sildenafil starts to work within 30 to 60 minutes. Its effects are usually strongest 1 hour after taking it, so you should plan to take it an hour before you want to have sex.

How long sildenafil takes to work can depend on a number of factors. It is more effective when taken on an empty stomach. Sildenafil will take longer to work if taken with food or shortly after eating.

Sildenafil is an effective treatment for erectile dysfunction for most men who take it. Clinical studies have found sildenafil to be effective in lasting erections for 62% of men at the 25mg dose, 74% of men at the 50mg dose, and 82% of men at the 100mg dose.

This means that sildenafil will work for most men who try it, depending on the dose and factors like your age and weight. However, if you find that sildenafil is not working for you after a few tries, alternative treatments are available.

You need to be sexually aroused for sildenafil to work. Sildenafil improves the way your body works naturally when you are aroused. This means you will not get an erection when taking sildenafil unless you are sexually aroused.

Take 1 sildenafil tablet an hour before you want to have sex, ideally on an empty stomach.

One hour before you have sex is the best time to take sildenafil as this is when its effects are usually strongest.

Never take more than your prescribed dose of sildenafil within 24 hours. Only take sildenafil when you need it, as advised by a doctor or pharmacist. Do not combine it with other medications for erectile dysfunction. Avoid alcohol and grapefruit juice while taking sildenafil as they can increase the risk of you experiencing side effects.

How much sildenafil to take

Sildenafil is available in 25mg, 50mg, and 100mg dosage strengths. The usual dose is 50mg, to be taken no more than once a day. This can be increased or decreased as needed.

25mg

25mg is the lowest dose of sildenafil, usually prescribed if you experience side effects on the standard 50mg dose if you have a medical condition or if you are also taking medications that lower blood pressure.

50mg

50mg is the standard dose of sildenafil. Most people will be prescribed 50mg as long as they have no medical conditions.

100mg

This is the highest possible dose of sildenafil. You may be prescribed 100mg if the 50mg dose is not effective for you, as long as you do not experience any adverse side effects.

Sildenafil is a prescription-only medication, to buy it you need a prescription from a doctor or pharmacist. You can request a prescription from your GP, or a safe and regulated online doctor service like Asda Online Doctor.

Can I buy sildenafil online?

Yes, you can get a prescription for sildenafil from safe and trusted online doctor services like Asda.

Getting a prescription for sildenafil with Asda is easy, just fill out our quick online consultation form and one of our doctors will make sure that sildenafil is right for you. If approved, you can choose from fast and discreet home delivery or collection from an Asda pharmacy.

Can I buy sildenafil over-the-counter?

You can get 50mg of sildenafil over-the-counter from most pharmacies after a consultation with a pharmacist. This is known as Viagra Connect. They will need to ask you some questions about your health and any other medications you take to make sure sildenafil is safe and appropriate for you. If they have any concerns they may recommend that you see your doctor.

Can I get sildenafil on the NHS?

Yes, you can get sildenafil on the NHS if you have erectile dysfunction. You will need to see your GP so they can make sure it is safe for you and give you a prescription. You cannot get branded Viagra on the NHS.

Sildenafil, like all medications, can have side effects. Not everyone who takes sildenafil will experience side effects and most side effects are mild to moderate and temporary.

Very common side effects (may affect more than 1 in 10 people) include:

• headache

Common side effects (may affect up to 1 in 10 people) include:

• nausea
• facial flushing
• hot flushes (a sudden feeling of heat in your upper body)
• indigestion
• visual disturbance (including a colour tinge to your vision or blurred vision)
• stuffy nose
• dizziness

Uncommon side effects (may affect up to 1 in 100 people) include:

• vomiting
• eye irritation
• watery eyes or bloodshot/red eyes
• pain in your eyes
• light sensitivity,
• visual disturbance (seeing flashes of light or visual brightness)
• a fast or pounding heartbeat
• high or low blood pressure
• muscle pain
• feeling sleepy
• reduced sense of touch
• vertigo
• ringing in the ears
• dry mouth
• blocked or stuffy sinuses or inflammation of the lining of the nose (symptoms include runny nose, sneezing and stuffy nose)
• upper abdominal pain
• gastro-oesophageal reflux disease (symptoms include heartburn)
• blood in your urine
• pain in the arms or legs
• nosebleed
• hypersensitivity
• rash
• chest pain

Rare side effects (may affect up to 1 in 1,000 people) include:

• fainting
• feeling irritable
• stroke
• heart attack
• temporary decreased blood flow to parts of the brain
• feeling of tightening of the throat
• numb mouth
• bleeding at the back of the eye
• double vision
• reduced sharpness of vision
• abnormal sensation in the eye
• swelling of the eye or eyelid
• small particles or spots in your vision
• seeing halos around lights
• dilation of the pupil of the eye
• discolouration of the white of the eye
• penile bleeding
• presence of blood in semen
• sudden decrease or loss of hearing

Seek medical help or advice if you experience any of these side effects, and call 111 or 999 in an emergency:

• an allergic reaction (wheeziness, breathing difficulties, dizziness, or swelling of the eyelids, face, lips or throat)
• chest pains during or after intercourse
• prolonged and sometimes painful erection which lasts for more than 4 hours
• a sudden decrease or loss of vision
• serious skin reaction, including peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes, or fever
• seizures or fits

It’s good to be aware of the possible side effects, just in case you experience them. You can find a detailed outline of sildenafil’s side effects in your patient information leaflet (included with your medication or online).

How long do sildenafil side effects last?

If you do experience side effects when using sildenafil for erectile dysfunction, they will most likely go away within a day or within your first week on the medication. It can sometimes help to eat something small with your tablet.

If you do experience side effects that are persistent (over 7 days), your Asda Online Doctor is here to help, simply message via your patient account or you can speak to a doctor or pharmacist for advice.

What to do if you get sildenafil side effects

If you get side effects when taking sildenafil, they will usually go away on their own after about a week. But, there are things you can try to help alleviate symptoms, such as:

• staying hydrated or taking painkillers can help to improve headaches
• avoiding alcohol and caffeine can help to improve facial flushing
• using a decongestant nasal spray can help if you are suffering with a blocked/stuffy nose
• avoiding rich or greasy food or getting fresh air can help with nausea
• resting can improve dizziness or tiredness

However, if you experience side effects that are uncomfortable or do not go away, seek advice from Asda Online Doctor or another medical professional.

If you experience any of the serious side effects of sildenafil you must not ignore it and seek medical help immediately. In an emergency, call 999. For example, if you experience:

• an allergic reaction (breathing difficulties, wheezing and the swelling of the lips, through, mouth or tongue)
• a painful erection or an erection lasting over 24 hours
• chest pain
• fits or seizures

Sildenafil may not be right for everyone - certain conditions or certain medications can interact with sildenafil and make it less effective, or potentially unsafe.

Do not take Sildenafil if you:

• are allergic to sildenafil
• do not have erectile dysfunction
• are under 18
• are a woman
• have low blood pressure
• have a serious heart or liver problem
• have recently had a heart attack, heart problem or stroke
• have a stomach ulcer
• have a bleeding problem (such as haemophilia)
• have a deformity of your penis or have Peyronie’s disease (curved penis)
• have sickle cell anaemia, leukaemia or multiple myeloma
• have ever had loss of vision because of non-arteritic anterior ischaemic neuropathy (NAION)
• have an inherited eye disease (such as retinitis pigmentosa)

Other medicines and sildenafil

Sildenafil tablets can interact with other medicines. Do not take sildenafil if you take any of the following:

• other treatments for erectile dysfunction, such as Cialis (tadalafil) or Levitra (vardenafil)
• angina or chest pain treatment called nitrates, such as glyceryl trinitrate (GTN) or isosorbide mononitrate
• treatment for pulmonary arterial hypertension such as riociguat
• HIV treatment, such as protease inhibitors
• alpha-blockers for high blood pressure, such as doxazosin or alfuzosin
• recreational drugs that affect your blood pressure, such as ‘poppers’ sold as leather cleaners or room ‘odourisers’
• certain antibiotics, such as erythromycin

Sildenafil is generally safe for most men who take it. If you are not sure whether Sildenafil is suitable for you, speak to a doctor or pharmacist. If sildenafil is not appropriate for you, you will not get a prescription for it.

Serious adverse side effects occur rarely and are most likely when someone takes sildenafil incorrectly. As this study explains, serious and adverse side effects occurred when men took sildenafil alongside other interacting medications or while having associated medical conditions, such as heart disease.

Sildenafil is not the only treatment available for erectile dysfunction. There are both medical and non-medical alternatives.

Medical alternatives

Other medications to treat erectile dysfunction are available from Asda Online Doctor. If you think sildenafil might not be right for you, instead consider:

Viagra

This medication works in the same way as sildenafil as they both contain the active ingredient sildenafil citrate. Viagra can be more expensive than sildenafil as it is a branded version of the medication.

Viagra Connect

This medication also works in the same way as sildenafil and contains the same active ingredient sildenafil citrate. It can only be bought in 50mg tablets and is available over the counter with a consultation with a pharmacist. Viagra and Viagra Connect are manufactured by the same company, Pfizer.

Tadalafil

This medication is similar to sildenafil. It also comes as a tablet and both medications are PDE-5 inhibitors, meaning they work in the same way. However, tadalafil can last up to 36 hours which is longer than sildenafil (lasts up to 6 hours).

Tadalafil is also sold under the brand name Cialis.

Vardenafil

This medication is another PDE-5 inhibitor, which means that it works in the same way as sildenafil. Vardenafil is also taken as a tablet at 10mg or 20mg.

Levitra

This medication is a branded version of vardenafil. It works in exactly the same way but differs in price and packaging.

Spedra

Spedra is a prescription erectile dysfunction medication, containing the active ingredient avanafil which is also a PDE-5 inhibitor. It comes as a tablet in doses of 50mg to 200mg.

Vitaros cream

Vitaros (active ingredient alprostadil) is a cream you apply directly to the tip of the penis. It can help you to get and keep an erection during sex even if there is nerve damage on the penis. Vitaros cream is an alternative to erectile dysfunction tablets like Viagra, vardenafil or Spedra if you would prefer not to take medication orally.

Non-medical alternatives

If you do not want to take medication for erectile dysfunction, there are some other things you can try, they include:

1: Penis pumps or rings may help to improve your erections. They can increase the pressure to cause more blood flow to the area and can also be used alongside ED medications.

2: Making lifestyle changes, for example:

• stopping smoking
• drinking less alcohol
• improving your diet
• doing regular exercise

3: Therapy – some men’s erectile dysfunction may be caused or worsened by psychological problems. If stress, anxiety, or depression are causing symptoms of erectile dysfunction then therapy may help.