Atracurium is metabolised by both Hofmann elimination and ester hydrolysis. Cisatracurium is a stereoisomer of atracurium. Which of the following is a key difference between cisatracurium and atracurium that makes cisatracurium safer in renal failure patients?

• A Cisatracurium undergoes predominantly renal elimination
• B Cisatracurium produces significantly less laudanosine, a CNS stimulant metabolite ✓
• C Cisatracurium is a depolarizing agent with faster metabolism
• D Cisatracurium is metabolised exclusively by plasma cholinesterase

Explanation

Both atracurium and cisatracurium undergo Hofmann elimination and ester hydrolysis, not renal or plasma cholinesterase metabolism. However, atracurium produces laudanosine as a byproduct of Hofmann elimination, which accumulates in renal failure and can cause CNS excitation and seizures. Cisatracurium produces much less laudanosine, making it safer in renal failure. Option D is wrong as mivacurium, not cisatracurium, is the non-depolarising agent metabolised by plasma cholinesterase.

Reference: Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.