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. It continues to work for up to 4 hours, although its action is usually less after 2 hours. You are encouraged to report adverse events related to Viatris products by calling U. This site is intended only for U. If you see air bubbles in the syringe, repeat the steps. Sildenafil should not be used with any other medicine or device that causes erections.Optum Store allows for bulk ordering in a , , and day supply. The price will vary based on the size of your order. if bought in a larger monthly supply. Brand-name Viagra is also. Brand names for sildenafil include Viagra, Revatio, and Liqrev. The cost for sildenafil oral tablet mg is around $10 for a supply of 2 tablets, depending on the pharmacy you . Optum Store allows for bulk ordering in a , , and day supply. The price will vary based on the size of your order. if bought in a larger monthly supply. Brand-name .