You need to be sexually excited for it to work. It’s used to treat men with erectile dysfunction, helping you to get and maintain an erection. This, in turn, leads to more nitric oxide in the body. Ask your pharmacist for a list of the ingredients. This medicine is available on prescription and you can also buy it from most pharmacies. Sildenafil Liqrev, Revatio is used to improve the ability to exercise in adults Liqrev, Revatio and children 1 year of age and older Revatio with pulmonary arterial hypertension PAH; high blood pressure in the vessels carrying blood to the lungs, causing shortness of breath, dizziness, and tiredness. Cialis stays in your system for up to 36 hours, and you can take it daily.You can use your Superdrug Online Doctor prescription to buy your erectile dysfunction treatment at any pharmacy in Ireland. Trustpilot. Use our online assessment to order. A . Who may not be able to take sildenafil. Sildenafil is not suitable for some people. To make sure it’s safe for you, speak to your doctor or pharmacist before taking sildenafil if you: have ever had an allergic reaction to sildenafil or any other medicine. have recently had a stroke, heart attack or a heart problem – your doctor should. Rarely reported side effects include: an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis. sudden vision loss in one or both eyes.