This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthesia, Subject name: Pharmacology
Which of the following drugs are believed to be effective in the treatment of post operative shivering? 
Select and explain. 
A. Ondansetron, B. Diclofenac sodium, C. Pethidine, D. Paracetamol
C: Pethidine
Answer: C: Pethidine 
Explanation: Ans. (C) Pethidine(Ref: Anesthesiology by Longnecker/1485; KDT 8th/e p503)Pethidine is most effective drug for treatment of post-operative shivering. Other drugs that can be used for this purpose are clonidine, doxapram, ketanserin and alfentanil.