When a man gets aroused, the brain sends signals to the body that tell vessels supplying the penis to open up. Is Viagra the best tablet for ED? Stop taking VIAGRA and call your healthcare provider right away if you have any sudden vision loss sudden hearing decrease or hearing loss. Please expect up to 4 to 6 weeks for reimbursement. Answer: In short, the drug in Viagra, Sildenafil, dilates blood vessels at the entrance to the penis. · Sildenafil for oral suspension contains sildenafil, which is the same medicine found in another medicine called VIAGRA ®. VIAGRA is used for the treatment of . This means that 4 hours after you take a dose, your body has cleared half of the dose. In most cases, it takes about 5 half-lives for your body to completely remove a Missing: packaging.  · Brand names: Revatio, Viagra Drug classes: Agents for pulmonary hypertension, Impotence agents. Medically reviewed by Kaci Durbin, MD. Last updated Missing: packaging.