Monitoring of serum levels of imipramine and desipramine and individualization of dose in enuretic children.

The serum levels of imipramine (IMI) and its active metabolite desipramine (DMI) were monitored in 90 children with primary nocturnal enuresis. Ages ranged between 5 and 14 years. Serum concentrations were determined in 21 children at 24 h after administration of a dose of 75 mg and once when steady state had been reached, 12 h after the last dose; a good correlation was seen between the total levels (IMI + DMI) on those two occasions (r = 0.81; p less than 0.01). This serves as a basis to predict the steady-state levels of IMI + DMI reached in an individual patient. In the remaining patients the serum levels of IMI + DMI were determined at steady state. Dosage regimens were adjusted individually to obtain a favorable response with regard to the frequency of enuresis and to the possible occurrence of side effects. Good correlation was established between the serum concentrations of IMI + DMI at steady state and the frequency of enuresis, with a favorable response being obtained for levels greater than 80 ng/ml. Monitoring of serum levels leads to better compliance with the regimen throughout treatment.