Atracurium pharmacokinetics

The major metabolic pathway for cisatracurium is Hofmann elimination, although renal and other organ clearance accounts for some elimination. The pharmacokinetics of cisatracurium are independent of dose in healthy adult patients up to doses of 0.2 mg-kg-1 and its elimination half-life is similar to that of atracurium (Table 6.4). In contrast to atracurium, the clearance of cisatracurium is slightly reduced and recoveiy slightly slower in patients with renal failure. Much less laudanosine is produced as a metabolite of cisatracurium as compared with atracurium even when the drug is given by continuous infusion over a prolonged period of time. 

Leslie K., Sessler D. I., Bjorksten A. R., and Moayeri A. (1995) Mild hypothermia alters propofol pharmacokinetics and increases the duration of action of atracurium. Anesth. Analg. 80, 1007-1014. 

Fahey MR, Rupp SM, Fisher DM, Miller RD, Sharma M, Canfell C, Castagnoli K, Hennis PJ. The pharmacokinetics and pharmacodynamics of atracurium in patients with and without renal failure. Anesthesiology 1984 61(6) 699-702. 

Ward S, Neill EA. Pharmacokinetics of atracurium in acute hepatic failure (with acute renal failure). Br J Anaesth 1983 55(12) 1169-72. 

Pharmacokinetics of atracurium and metabolites in normal and renal failure patients. Anesthesiology 1987 67 A606. 

Tsui D, Graham GG, Torda TA. The pharmacokinetics of atracurium isomers in vitro and in humans. Anesthesiology I987 67(5) 722-8. 

Patients with burns require more D-tubocurarine (and higher plasma concentrations) for the same degree of blockade compared with non-burned patients (6). The mechanism is not known, but it appears not to be altered pharmacokinetics (7). The resistance to non-depolarizing neuromuscular blocking agents (SEDA-8,136) appears to be influenced by the size of the body surface area burned and by the time which has elapsed since the injury (see Atracurium). In extensive burns dose requirements are increased approximately by a factor of 2-3. 

Pharmacokinetics All agents are given parenterally. Drugs that are metabolized (eg, mivacurium, by plasma cholinesterase) or eliminated in the bile (eg, vecuronium) usually have shorter durations of action than those eliminated by the kidney (eg, doxacurium, pancuronium, tubocurarine). Atracurium clearance involves spontaneous breakdown (Hofmann elimination) to form laudanosine and other products is largely independent of hepatic or renal function. 

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