Friday September 14, 2007
Regarding cisatracurium and its metabolite !

Cisatracurium is a drug of choice for neuro-muscular blockade in patients with multi-system organ failure.The metabolism of cisatracurium is largely independent of major organs such as liver or kidney. 80% of cisatracurium undergoes Hofmann elimination in plasma which is only a PH and temperature-dependent chemical process and degrade into metabolites.

Dosing: 0.15 to 0.2 mg/kg IV bolus followed by 1 to 3 mcg/kg/min(range: 0.5 to 10.2 mcg/kg/min).

Recently there is a interest in one of the metabolite called Laudanosine. Laudanosine is a metabolite of the cisatracurium with potentially toxic systemic effects. It crosses the blood–brain barrier and may cause excitement and seizure activity. In the cardiovascular system,high plasma concentrations may produce hypotension and bradycardia. In hepatic failure, its elimination half life is prolonged. Also, patients with renal failure have higher plasma concentrations of Laudanosine and a longer mean elimination half-life. Laudanosine crosses the placental barrier.

But all these effects seem theoretical and laudanosine accumulation and related toxicity seem unlikely to be achieved in clinical practice particularly with cisatracurium.


Related previous pearl: Tachyphylaxis Associated With Continuous Cisatracurium (Nimbex)



Reference - click to get abstract / article

1. cisatracurium - rxlist.com

2. Laudanosine, an atracurium and cisatracurium metabolite - European Journal of Anaesthesiology 2002; 19: 466–473