But, some side effects, including flushing, heartburn, sinus congestion, and headaches, might prevent some men from taking them even though they work well. But, keep in mind that ED might signal an underlying medical problem, like high blood pressure, heart disease, diabetes, low testosterone, or sleep apnea. It is eliminated predominantly by hepatic metabolism mainly CYP3A4 and is converted to an active metabolite with properties similar to the parent, sildenafil. Some people may also have ringing in their ears tinnitus or dizziness. There were some reports of headaches and nausea, however. The pharmacokinetics of sildenafil in patients with severely impaired hepatic function Child-Pugh Class C have not been studied [see Dosage and Administration 2. You are encouraged to report adverse events related to Viatris products by calling U.Examples of Viagra’s more commonly reported side effects include: headache. flushing (temporary warmth, redness, or deepening of skin color) stuffy nose. indigestion (upset stomach) mild vision. VIAGRA can cause your blood pressure to drop suddenly to an unsafe level if taken with certain other medicines. Do not take VIAGRA if you take any other medicines called “nitrates.” Nitrates are used to treat chest pain (angina). A sudden drop in blood pressure can cause you to feel dizzy, faint, or have a heart attack or stroke. According to price-comparison site , generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s compared with more than $50 per.