Sildenafil tablets are usually taken three times a day to improve your ability to exercise.

You may need to spend a day in hospital when you start treatment, before returning home and carrying on taking the medicine. How long you can take sildenafil for will depend on your condition. If at any time your condition gets worse, you may be given additional treatment as well as, or instead of, sildenafil.

Sildenafil may not be suitable for you if you:

  • are also taking medicines or drugs that contain nitrates – organic nitrates are often used to treat angina and amyl nitrate is a recreational drug commonly known as "poppers"
  • have a severe liver problem
  • have recently had a heart attack or stroke
  • have severe low blood pressure (hypotension)
  • have certain eye conditions

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