· Description and Brand Names. Drug information provided by: Merative, Micromedex® US Brand Name. Revatio; Viagra; Descriptions. Sildenafil is used to treat .The decision, Teva Canada Ltd. Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine. Sildenafil is also used in both men and women to treat the symptoms of pulmonary arterial hypertension. Its effects often last for 4 to 5 hours. Seven of these companies are based in India. What should I do if I forget a dose?Common Viagra side effects may include: flushing (warmth, redness, or tingly feeling); headache, dizziness; abnormal vision (blurred vision, changes in color vision) runny or stuffy nose, nosebleeds; sleep problems . Viagra is a brand-name medication that contains the active drug sildenafil. This active drug comes as a generic medication, too. Sildenafil and brand-name Viagra are both used to treat ED.  · Generic name: sildenafil (oral) [ sil-DEN-a-fil ] Brand names: Revatio, Viagra Drug classes: Agents for pulmonary hypertension, Impotence agents. Medically reviewed by Kaci Durbin, MD. Last updated on Uses; Warnings; Before taking; Dosage; Side effects; Interactions; FAQ; What is sildenafil?Your doctor may need to change the doses of your medications or monitor you carefully for side effects. While the sale remains subject to a consultation with a pharmacist, the other restrictions from the trial have been removed, allowing customers over the age of 18 to purchase an unlimited number of pills. If you are taking sildenafil for PAH, take the missed dose as soon as you remember it. The patent was published in and expired in Recent heart or blood vessel problems.