The pharmacokinetics of sildenafil are dose-proportional over the recommended dose range. It might work longer if you have mild to moderate erectile dysfunction. Generic versions of sildenafil, vardenafil and tadalafil are available. Sore throats are common, but not dizziness, vision changes, nausea, or muscle aches. It might work longer if you have mild to moderate erectile dysfunction. The pharmacokinetics of sildenafil in patients with severely impaired hepatic function Child-Pugh Class C have not been studied [see Dosage and Administration 2. It comes in doses ranging from 5 mg up to 20, as well as more easy-to-hide tablets that disintegrate under the tongue.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . Viagra (sildenafil) is approved to treat sexual dysfunction in men by the U.S. Food and Drug Administration (FDA), but it is sometimes prescribed to women off-label, which means without approval by the FDA. Viagra is an effective drug for treating male erectile dysfunction, but it targets sexual performance, not sexual arousal. Examples of these products include: dehydroepiandrosterone (DHEA) ginseng yohimbine.