Taking sildenafil alone will not cause an erection. Some people may also have ringing in their ears tinnitus or dizziness. If you’re not sure if you’re taking a nitrate, ask your doctor or pharmacist. This medicine is available on prescription and you can also buy it from most pharmacies. Sildenafil is also sometimes used to treat pulmonary hypertension high blood pressure in the blood vessels that supply the lungs. This site is intended only for U. It can be dangerous to take sildenafil if you also take medicines called nitrates often given for chest pain.Get drug information. Search for a drug by name or NDC number and get complete drug information. It’s like the printout attached to your refill—only electronic. Help me find my info. Search by name. Search by NDC. Enter medication name (Ex. “Lipitor”). Getting a 3-month supply. You may be able to get a day supply of Viagra. If approved by your insurance company, getting a day supply of the drug could reduce your number of trips to the. Compare prices and print coupons for Viagra (Sildenafil) and other drugs at CVS, .