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
Muscle relaxant safe in renal failure patient is:- 
Select and explain. 
A. Pancuronium, B. Piperacuronium, C. Tubocurarine, D. Atracurium
D: Atracurium
Answer: D: Atracurium 
Explanation: Atracurium and cis-atracurium undergo Hoffmann's elimination (spontaneous non-enzymatic molecular rearrangement) and are the agents of choice for patients with hepatic or renal insufficiency. Atracurium is metabolized to laudanosine that is responsible for seizures. Cis-atracurium is relatively safe in this regard. Cis-atracurium release much less histamine as compared to atracurium.