Hearing problems: Rarely, people taking Cialis Tadalafil have experienced a sudden decrease or loss of hearing. Avanafil Stendra. Vardenafil usually works for 4 to 5 hours. This medicine also works best when you take it an hour before sex on an empty stomach. Free Delivery Your medication is delivered directly to you at no added cost. Oral medicines for ED usually work well and cause few side effects. Lower doses of Cialis Tadalafil should be used if you have impaired kidney function.Tadalafil (Cialis). This medication is taken with or without food an hour before sex. It works for up to 36 hours. You can take it in a small dose daily or in a larger dose as needed. . Generic Cialis is called Tadalafil and you could save up to 90% on the price of your medication by buying brand or generic Cialis online through Canadian Pharmacy Meds. . not available over-the-counter (OTC) Was this helpful? How does Cialis work? Cialis works by increasing blood flow to the penis to help a person get and maintain an .