This increase in blood flow results in a firmer, longer-lasting erection. Is there any difference between Viagra and Sildenafil? People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. Answer: No. Never purchase ED medications from a site or service that doesn’t require a prescription and medical documentation. However, some states require a live video consultation. These PDE5 inhibitors may cause headache, flushing, drop in blood pressure, or other adverse effects.Does the price of sildenafil vary based on strength or what it’s prescribed for? 25 mg, 50 mg, mg: PAH treatment: oral tablet: 20 mg: liquid suspension: 10 . Want to see these pharmacies on a map and filter by available services? How much does sildenafil citrate or revatio cost near you? Find the best sildenafil citrate or revatio . DRUG_DESCRPTION Compare DRUG_NAME prices and find coupons that could save you up to 80% instantly at pharmacies near you such as CVS, Walgreens, Walmart, and .