Sildenafil comes as a tablet and suspension liquid to take by mouth. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail. If you are taking sildenafil for erectile dysfunction, your doctor will probably start you on an average dose of sildenafil and increase or decrease your dose depending on your response to the medication. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking sildenafil. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. This product is available in the following dosage forms: Tablet Suspension There is a problem with information submitted for this request. Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient. · Sildenafil under the name Viagra is used to treat erectile dysfunction (impotence) in men. Another brand of sildenafil is Revatio, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. Do not take Viagra while also taking Revatio. Warnings. Sildenafil is in a class of medications called phosphodiesterase (PDE) inhibitors. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation. This increased blood flow can cause an erection. Sildenafil treats PAH by relaxing the blood vessels in the lungs to allow blood to flow easily.  · Viagra; Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where .