Targeting imipramine dose in children with depression.

The response to imipramine (IMI) in children with depression has been shown to correlate with total levels of IMI plus its active metabolite desmethylimipramine (DMI). The pharmacokinetics of IMI + DMI in children with depression are examined, and the single-point prediction of steady-state IMI + DMI levels at minimum therapeutic concentrations for prepubertal depression is proposed. With a single, 25 mg oral dose of IMI, a plasma concentration of IMI + DMI 24 hours after dosing correlates (r = 0.92) with steady-state IMI + DMI levels in children with depression receiving 3 mg/kg/day IMI. The targeting of IMI dose in the child population with depression to rapidly achieve a minimum therapeutic concentration is shown to be feasible and reliable within theoretic limits.