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. Some providers may prescribe Viagra off-label for uses not intended or approved but that may be beneficial for women. It Targets the Problem and Works Quickly. This site is intended only for U. Oral ED medications are generally well-tolerated, Dr.AdFree & Private Online Consultant with Real Doctors. Reliable E.D. Meds Shipped Discreetly. Save Time & Money with Online Prescription for Viagra, Cialis, Sildenafil and Shipping · Real Doctors · Discreet Packaging · Personalized Plan/5 (3, reviews)Generic Viagra – $ · Cialis Daily – $ · Tadalafil – $ · Sildenafil – $  · 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. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. VIAGRA may affect the way other medicines work, and other medicines may affect the way VIAGRA works, causing side effects. Especially tell your healthcare provider if you take any of the following.