<prompt> Which of the following opioid should not be used with MAO inhibitors?MorphinePentazocineBuprenorphinePethidine  <response>: Ref: KD Tripathi 6e p440 Most of Pethidine is metabolized by MAO-A and is inactivated. Small amount is conveed to nor-Pethidine, which has CNS stimulant propeies. Therefore if combined with MAO inhibitors, most of Pethidine will form nor-Pethidine and the risk of seizures will increase. 