Do not use more of it and do not use it more often than your doctor ordered. Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. Your doctor may adjust your dose if needed. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. Sexual activity may be a strain on your heart, especially if you have heart disease. Sildenafil comes as a tablet and suspension liquid to take by mouth.Sildenafil oral tablet is used to treat erectile dysfunction (ED). It’s also used to treat pulmonary arterial hypertension (PAH). What is sildenafil? Sildenafil is a prescription . AdSave Time & Money with Online Prescription for Viagra, Cialis, Sildenafil and Tadafil. Free & Private Online Consultant with Real Doctors. Reliable E.D. Meds Shipped Shipping · Discreet Packaging · Real Doctors · Personalized Plan/5 (3, reviews). VIAGRA is available by prescription only in 25 mg, 50 mg, and mg tablets. Patients should always ask their doctors for medical advice about adverse events. You are encouraged to report adverse events related to Viatris products by calling (U.S. only). If you prefer, you may contact the U.S. Food and Drug Administration (FDA.