<prompt> Which of the following anaesthetic drugs is contraindicated in chronic renal failureMorphineFentanylPethidineAtracurium  <response>: Pethidine Meperidine is metabolized to form normeperidine long half life which is excreted by the kidney. Administration of pethidine to a patient with Chronic Renal Failure causes toxic accumulation of this metabolite and is hence contraindicated. 