You should resume taking the medication you were taking prior to your surgery unless told not to. However, you should stay off aspirin or aspirin-containing products until after the catheter comes out and for at least four weeks following surgery.
You will be given a prescription for pain killers for discomfort at the incision site. Most men following prostatectomy rely only on extra strength acetaminophen at home and do not require narcotic pain medication. You will also be given a prescription for an antibiotic to take around the time the catheter comes out. Typically it will be a three-day course of antibiotics, which you'll need to start on the day prior to your scheduled cystogram appointment.