When to avoid sildenafil

You should be careful with sildenafil if:

• have ever had an allergic reaction to sildenafil or any other medicine
• are taking medicines called nitrates for chest pain (angina)
• have a serious heart or liver problem
• have recently had a stroke, heart attack or a heart problem – your doctor should carefully
check whether your heart can take the additional strain of having sex
• have low blood pressure (hypotension)
• have a bleeding problem like haemophilia
• have a rare inherited eye disease, such as retinitis pigmentosa
• have a stomach ulcer
• have sickle cell anaemia (an abnormality of red blood cells), leukaemia (cancer of blood cells) or multiple myeloma (cancer of bone marrow)
• have a deformity of your penis or Peyronie's disease (curved penis)