Children ( n = 151 ) undergoing tonsillectomy ( c. 1995 ) were randomized to receive acetaminophen elixir 40mgkg ( -1 ) before surgery and 20mgkg ( -1 ) rectally at the end of surgery with diclofenac suspension 0.1 mgkg ( -1 ) , 0.5 mgkg ( -1 ) , or 2.0 mgkg ( -1 ) before surgery or placebo .