If you ever need emergency medical treatment for a heart problem, the healthcare providers who treat you will need to know when you last took sildenafil. Different brands may not work the same way. However, the dose is usually not more than 80 mg 3 times a day. Make sure you tell your doctor if you have any other medical problems, especially: Abnormal penis, including a curved penis or birth defects of the penis—Chance of problems occurring may be increased and this medicine should be used with caution in these patients. The following nonprescription or herbal products may interact with sildenafil: cimetidine Tagamet HB , St. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. Children—Use is not recommended.Sildenafil (Generic Viagra, Revatio) is medication used to treat erectile dysfunction (ED) in men who suffer from impotence, or the inability to get or maintain an test1.ru combination with sexual stimulation, sildenafil works by increasing blood flow to the penis to help a man get an erection and maintain it during sexual intercourse. AdGet a Prescription for ED treatment, discreetly deliverED to your door. 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 .