take medicines referred to as "nitrates" (like nitroglycerin) use Road drugs known as "poppers" for example amyl nitrate or amyl nitrite, and butyl nitrate acquire any medicines known as guanylate cyclase stimulators such as riociguat (Adempas) are allergic to sildenafil, as contained in Viagra® and Revatio, or any on the ingredients in Viagra®.E