According to UPI, research has shown that intravenous acetaminophen had no additional benefits over oral Tylenol for patients undergoing colorectal procedures. IV acetaminophen, marketed as Ofirmev and manufactured by Mallinckrodt Pharmaceuticals, was introduced in the United States in 2010. A typical oral tablet of acetaminophen costs a few cents, but the IV version's wholesale is $13 for a 1 gram vial.