· Proper Use. Drug information provided by: Merative, Micromedex ®. Use sildenafil exactly as directed by your doctor. Do not use more of it and do not use it more often than your doctor ordered. If too much is used, the chance of side effects is increased. This medicine comes with a patient information leaflet.Use the oral syringe provided with your medication to measure and take your dose. Its effects might last longer if you have mild to moderate ED. You may take this medicine with or without food. Sildenafil usually should not be taken more than once every 24 hours. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Do not press on the plunger of the syringe.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. 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 . Sildenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, sildenafil works by increasing blood flow to the penis.  · Proper Use. Drug information provided by: Merative, Micromedex ®. Use sildenafil exactly as directed by your doctor. Do not use more of it and do not use it more often than your doctor ordered. If too much is used, the chance of side effects is increased. This medicine comes with a patient information leaflet.You should only be treated with one of these products at a time. This will increase the supply of blood to the lungs and reduce the workload of the heart. 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. This medicine works best when you take it on an empty stomach an hour before sex. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. What should I do if I forget a dose? Tadalafil Cialis.