Kinetics of intercompartmental disposition and excretion of tubocurarine, gallamine, alcuronium and pancuronium in patients with normal and impaired renal function.

Pharmacokinetic data of tubocurarine, gallamine, alcuronium and pancuronium in patients with normal and without renal function are taken from the literature. They are adapted to an open three compartment pharmacokinetic model, and the proportional intercompartmental distribution is calculated as a function of time from 1 min to 8 h. All drugs show similar kinetic properties: During the first 10 min rapid disappearance from compartment 1 results in saturation of compartment 2. Maximum saturation of compartment 3 is achieved after 1 to 2 h followed by a gradual disappearance of the relaxants from the whole system. 20-25% of the dose undergo sequestration apart from intercompartment equilibrium. In normal individuals sequestration is observed after 2 to 3 h whereas in anuric patients it is already demonstrated during the first hour. Intercompartmental redistribution is the basic principle governing the pharmacodynamic profile of all of the four drugs if given in clinical dosage.