Create a List of Your Concerns You need to have a plan when consulting your doctor for a specific case. If you are taking sildenafil to treat erectile dysfunction, follow your doctor’s directions and the guidelines in this paragraph. Do not press on the plunger of the syringe. Sildenafil does not prevent pregnancy or the spread of sexually transmitted diseases such as human immunodeficiency virus HIV. The following nonprescription or herbal products may interact with sildenafil: cimetidine Tagamet HB , St. Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases.Your doctor can prescribe VIAGRA if he or she thinks it’s right for you. VIAGRA OFFERS SAVINGS TO PATIENTS. If eligible, patients may save 50% on up to 12 prescriptions of brand-name VIAGRA annually–and could save up to $4, a year.* Patients should always ask their doctors for medical advice about adverse events. You are encouraged . 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 . Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP.