Abstract
This paper reviews the studies in which neuromuscular blocking drugs were comapred in at least two different age groups of patients. Most recent studies have lead to a uniform concept of the variation of the effect of these drugs in different age groups. In general, the dose of a nondepolarizing agent required to produce a particular degree of relaxation is similar in neonates (less than one month), infants (one to twelve months) and adolescents (more than thirteen years). However, in children from three to ten years the dose is significantly greater. The maximal effect is reached more quickly in neonates and infants than in the older children and adolescents. These results can be explained by changes in sensitivity, distribution volume and muscle mass. The duration of effect of a nondepolarizing agent is significantly altered by age only in the case of vecuronium, which has a prolonged action in neonates and infants. Suxamethonium remains as the agent with the most rapid onset.