What should I do if I forget a dose? If you become pregnant while taking sildenafil, call your doctor. Sildenafil is in a class of medications called phosphodiesterase PDE inhibitors. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. Generic versions of sildenafil, vardenafil and tadalafil are available. · Drug information provided by: Merative, Micromedex ® US Brand Name Revatio 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. Drugs & Medications Viagra Viagra – Uses, Side Effects, and More Generic Name (S): sildenafil Uses Sildenafil is used to treat male sexual function problems (impotence or erectile. Viagra is a brand-name medication. It’s also available in a generic form called sildenafil. How does Viagra work and how long does it last? You may have questions related to how Viagra.