Serial monitoring and achievement of steady state nortriptyline plasma levels in depressed children and adolescents: preliminary data.

Children and adolescents 6 to 16 years old (N = 25), who were diagnosed as having major depressive disorder, received a fixed daily dose of nortriptyline during an 8-week period. Nortriptyline plasma levels were drawn and assayed weekly. Data were analyzed for the total sample (N = 25) and separately for the subgroup of 6 to 9 year olds (N = 9) and for the subsample of 10 to 16 year olds (N = 16). There were no significant differences between the day 7 (week 1) plasma levels and the means of weeks 2 to 8 or between the means of weeks 1 to 4 and 5 to 8 within the total sample or within either subgroup. These findings suggest that nortriptyline steady state plasma levels within the pediatric age range are achieved by day 7 (week 1) and that nortriptyline (during the pediatric years) does not induce its own metabolism during an 8-week period. The achievement of steady state by day 7 is similar to that found in adults. The mean coefficients of variation were calculated for the total sample and for each subsample and were 13.7 +/- 4.0% (range, 8 to 20%) for the 6 to 9 year olds; 13.8 +/- 3.2% (range, 10 to 21%) for the 10 to 16 year olds; and 13.8 +/- 3.4% (range, 8 to 21%) for the total sample. These coefficients of variation are similar to the 10 to 20% range reported in adult subjects.(ABSTRACT TRUNCATED AT 250 WORDS)