There are many safe, reliable online services offering ED prescriptions. Sildenafil for pulmonary hypertension can also be known by the brand names Revatio and Grandipam. This increase in blood flow results in a firmer, longer-lasting erection. Take sildenafil as needed before sexual activity. Rarely reported side effects include: an erection that will not go away priapism. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule.AdWith RexMD you’re saving time and money with our Viagra delivery. Get started now. Reliable E.D. meds prescribed by real doctors. Get your free & private online visit todayFree Shipping · Real Doctors · Discreet Packaging · Personalized PlanTypes: Premature Ejaculation · Privacy Policy · Sexual Health. Compare prices and print coupons for Viagra (Sildenafil) and other drugs at CVS, Walgreens, and other pharmacies. Prices start at $ Learn about uses, how it works, and more for Viagra (sildenafil). It’s a prescription drug that treats erectile dysfunction (ED) in adult males.