Age-dependent dose-response relationship of ORG NC 45 in anaesthetized patients.

The effects of age on the dose of Org NC 45 were studied in 24 healthy, anaesthetized patients using an on-demand infusion of the drug which produced a stable twitch height of 10% of its initial value. The patients were allocated as follows: group I = age less than 40 yr; group II = 40-60 yr and group III = age greater than 60 yr. A steady-state dose measured every 10 min, was achieved in all the patients 30 min after the start of the administration of Org NC 45. Significant decreases of steady-state dosage requirement (P = 0.01) and rate of recovery from blockade (P less than 0.01) were observed between group III and the other two groups.