Early and late reversibility of rocuronium bromide

A computer simulation has been developed based on pharmacodynamic-pharmacokinetic modelling of the effect of neostigmine on rocuronium-induced neuromuscular blockade. The results of a previous study involving 60 patients were used as a test of the model. The model predicts that administration of neostigmine 40 micrograms kg-1 within 20 min of the administration of rocuronium does not decrease the duration of the block until 90% recovery has taken place. The optimum dose of neostigmine depends on the degree of block at the time of administration: for a more intense block the optimum dose is 80 micrograms kg-1 and for a less intense block is about 30 micrograms kg-1. The pharmacokinetic behaviour rather than the potency of the relaxant determines its reversibility.