take medicines called "nitrates" (for instance nitroglycerin) use Avenue medications known as "poppers" such as amyl nitrate or amyl nitrite, and butyl nitrate get any medicines called guanylate cyclase stimulators such as riociguat (Adempas) are allergic to sildenafil, as contained in Viagra® and Revatio, or any of your elements in Viagra®.Mecha