Which opioid does not require kidney & liver for metabolism -

Ans. is 'a' i.e., Remifentanylo Fentanyl80-100 times more potent than morphine.It is used in anaesthesia as neuroleptic analgesia^'anaesthesia.Transderma! patch is used in cancer or other types of chronic pain.It causes postoperative muscle rigidity,o AlfentanylAlfentanyl is seldom used now.It is shortest actingo RemifentanylFaster acting than other fentanyl congeners.Unique in that it is metabolized by plasma estreases, so dose reduction is not required in renal and hepatic failure,o SufentanylMost potent opioid (propoxyphene and mepridine are least potent opioid) ?? Mainly used in anaesthesia.All fentanyl congneres can produce truncal rigidity on rapid i.v. infusiono RememberSufentanil is most potent opioid analgesic - Katzung 10th/e p. 491Mepridine (Pethidine) and propoxyphene are least potent opioid analgesics.