<prompt> Muscle relaxant safe in renal failure patient is:-PancuroniumPiperacuroniumTubocurarineAtracurium  <response>: Atracurium and cis-atracurium undergo Hoffmanns 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. 