CORRELATION BETWEEN AGE AND PLASMA LEVEL/DOSAGE RATIO FOR PHENOBARBITAL IN INFANTS AND CHILDREN

Abstract

Plasma concentration measurements [123] of phenobarbital [an anticonvulsant] were obtained from 82 children (2 mo.-6 1/2 yr old) at steady-state conditions. The plasma level/dosage ratio has a highly significant correlation with the age of the patient both for dosage in mg/kg and in mg/m2. The ratio increases with the increase in the age of the patient at a rate which is greater for dosages expressed on the basis of body weight. Moreover, at least for body weight related dosages, this increase in relatively high in the 1st year of life, becoming less marked after. Practical indications are given about the required dosage of phenobarbital in different groups of ages from 2 mo. up to 6 1/2 yr. It is recommended however to regularly measure the plasma level of the drug in infants and children treated for long periods of time.