The following nonprescription or herbal products may interact with sildenafil: cimetidine Tagamet HB , St. If it is not treated right away, priapism can permanently damage your penis sudden vision loss in one or both eyes. These include itraconazole Sporanox, Tolsura , ketoconazole Extina, Ketozole, others and ritonavir Norvir. A newer form of the medicine that dissolves on the tongue might work faster than the pill that you swallow. Do not stop taking sildenafil without talking to your doctor. Especially tell your healthcare provider if you take any of the following: medicines called nitrates medicines called guanylate cyclase stimulators such as Adempas riociguat medicines called alpha-blockers, such as Hytrin terazosin HCl , Flomax tamsulosin HCl , Cardura doxazosin mesylate , Minipress prazosin HCl , Uroxatral alfuzosin HCl , Jalyn dutasteride and tamsulosin HCl , or Rapaflo silodosin.The generic name for Viagra is sildenafil. The drug also has another brand name: Revatio. It works by slowing down the action of PDE5, What is the closest thing to Viagra over-the-counter? 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 . Extra 15% off $30 sitewide with code SAVE15; Clip your mystery deal! BOGO 50% off select Walgreens health & wellness.