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Sildenafil Citrate (Sildenafil 25mg tablets)



Information specific to: Sildenafil 25mg tablets when used in Erectile dysfunction.

Sildenafil citrate (sil-den-af-fil sit-rate) is a medicine which is used in treating erectile dysfunction.

The information in this Medicine Guide for Sildenafil citrate varies according to the condition being treated and the particular preparation used.

Your medicine

Sildenafil citrate is used in the treatment of erectile dysfunction in men. It works by relaxing muscles in the walls of the blood vessels. Sexual stimulation increases the blood flow to the penis. Following sexual stimulation, Sildenafil citrate helps to produce an erection that is suitable for sexual activity.

Sildenafil citrate is not suitable for women or anyone under 18 years of age.

Other information about Sildenafil citrate:

  • your prescriber may vary the dose of your medicine to find what is best for you

Do not share your medicine with other people. It may not be suitable for them and may harm them.

The pharmacy label on your medicine tells you how much medicine you should take. It also tells you how often you should take your medicine. This is the dose that you and your prescriber have agreed you should take. You should not change the dose of your medicine unless you are told to do so by your prescriber.

If you feel that the medicine is making you unwell or you do not think it is working, then talk to your prescriber.

Whether this medicine is suitable for you

Sildenafil citrate is not suitable for everyone and some people should never use it. Other people should only use it with special care. It is important that the person prescribing this medicine knows your full medical history.

Your prescriber may only prescribe this medicine with special care or may not prescribe it at all if you:

  • are allergic or sensitive to or have had a reaction to any of the ingredients in the medicine
  • have a medical condition that stops you from engaging in sexual activity. This includes certain heart and circulation problems such as angina
  • have bleeding problems
  • have conditions which increase the risk of priapism such as sickle cell anaemia, leukaemia or multiple myeloma
  • have had a stroke
  • have hereditary eye disorders
  • have liver problems
  • have loss of vision
  • have low blood pressure
  • have penile problems such as a deformed penis, Peyronie's disease or penile scarring
  • have recently had a heart attack
  • have stomach ulcers

Furthermore the prescriber may only prescribe this medicine with special care or may not prescribe it at all for someone who is under 18 years of age.

As part of the process of assessing suitability to take this medicine a prescriber may also arrange tests:

  • to determine whether or not the medicine is suitable and whether it must be prescribed with extra care
  • to check that this medicine is not having any undesired effects

Over time it is possible that Sildenafil citrate can become unsuitable for some people, or they may become unsuitable for it. If at any time it appears that Sildenafil citrate has become unsuitable, it is important that the prescriber is contacted immediately.


Alcohol can interact with certain medicines.

In the case of Sildenafil citrate:

  • there are no known interactions between alcohol and Sildenafil citrate


Medicines can interact with certain foods. In some cases, this may be harmful and your prescriber may advise you to avoid certain foods.

In the case of Sildenafil citrate:

  • this medicine interacts with grapefruit juice. Grapefruit juice increases the level of Sildenafil citrate in your blood

If your diet includes any of the above, speak to your prescriber or pharmacist for further advice.

Driving and operating machinery

When taking any medicine you should be aware that it might interfere with your ability to drive or operate machinery safely.

In the case of Sildenafil citrate:

  • this medicine could affect your ability to drive or operate machinery

You should see how this medicine affects you before you judge whether you are safe to drive or operate machinery. If you are in any doubt about whether you should drive or operate machinery, talk to your prescriber.

Family planning and pregnancy

This medicine must not be taken by women so its effects in pregnancy are not known.


This medicine must not be taken by women so its effects on breast-feeding are not known.

Taking other medicines

If you are taking more than one medicine they may interact with each other. At times your prescriber may decide to use medicines that interact, in other cases this may not be appropriate.

The decision to use medicines that interact depends on your specific circumstances. Your prescriber may decide to use medicines that interact, if it is believed that the benefits of taking the medicines together outweigh the risks. In such cases, it may be necessary to alter your dose or monitor you more closely.

Tell your prescriber the names of all the medicines that you are taking so that they can consider all possible interactions. This includes all the medicines which have been prescribed by your GP, hospital doctor, dentist, nurse, health visitor, midwife or pharmacist. You must also tell your prescriber about medicines which you have bought over the counter without prescriptions.

The following medicines may interact with Sildenafil citrate:

  • amlodipine
  • amyl nitrite
  • bosentan
  • cimetidine
  • dipyridamole
  • doxazosin
  • erythromycin
  • itraconazole
  • ketoconazole
  • nicorandil
  • rifampin
  • ritonavir
  • saquinavir
  • theophylline

The following types of medicine may interact with Sildenafil citrate:

  • alpha-blockers
  • cytochrome P450 enzyme inducers
  • cytochrome P450 enzyme inhibitors
  • endothelin antagonist
  • nitrates
  • nitric oxide donors
  • other medicines used to treat erectile dysfunction
  • phosphodiesterase type-5 inhibitors
  • protease inhibitors

If you are taking Sildenafil citrate and one of the above medicines or types of medicines, make sure your prescriber knows about it.

Complementary preparations and vitamins

Medicines can interact with complementary preparations and vitamins. In general, there is not much information available about interactions between medicines and complementary preparations or vitamins.

If you are planning to take or are already taking any complementary preparations and vitamins you should ask your prescriber whether there are any known interactions with Sildenafil citrate.

Your prescriber can advise whether it is appropriate for you to take combinations that are known to interact. They can also discuss with you the possible effect that the complementary preparations and vitamins may have on your condition.

If you experience any unusual effects while taking this medicine in combination with complementary preparations and vitamins, you should tell your prescriber.

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