My sister had a laminectomy yesterday. During the night she had to void, but was not able to. Because of the large amount of fluids given during the surgery, she had to be catheterized. The nurse told her she had a lot of blisters around her meatus and the apparently they were in the urethra also. The only different meds she was taking prior to surgery was Oxycodone with Acetaminophen, Ketorolac, Nortriptyline, and some OTC potassium due to sever leg cramps. Could any of these meds have caused these blisters? Thank you for any suggestions you have. Am I supposed to pay for the answer?