Interactions. 1. How it works. Sildenafil may be used to treat erectile dysfunction (ED or impotence) in men (Viagra brand) or pulmonary arterial hypertension in both men and .Ask your pharmacist for a list of the ingredients. Sildenafil may cause side effects. Your doctor or other health care professional can recommend one for you based on these factors, other health conditions you have and any other medicines you take. Viagra is also informally known as “vitamin V”, “the blue pill”, or “blue diamond”, as well as various other nicknames. Follow the manufacturer’s directions to use and clean the oral syringe. This boosts blood flow and helps you get an erection from sexual activity.Drug Images Viagra treats erectile dysfunction (ED) in adults. It’s usually taken about 1 hour before sexual activity. Below, you’ll find information about recommended dosages . Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or alcohol. Its effects . Viagra is a brand-name prescription drug that’s approved to treat erectile dysfunction (ED). With ED, you’re unable to have or maintain an erection. Viagra is approved for this use .United States Sildenafil is available as a generic drug in the United States, labeled for pulmonary arterial hypertension. Some medications should not be taken with sildenafil. Oral medicines for ED usually work well and cause few side effects. Its effects might last longer if you have mild to moderate ED. An inherited eye disease that affects the retina. How should this medicine be used?