Single-dose kinetics predict steady-state concentrations on imipramine and desipramine.

Single-dose prediction of ultimate steady-state concentrations of tricyclic antidepressants at the outset of treatment can be a valuable therapeutic tool that has had only limited application. We demonstrate accurate steady-state predictions following both the tertiary amine, imipramine hydrochloride, and the secondary amine, desipramine hydrochloride, in a carefully monitored long-term treatment patient population. Results show that long-term treatment does not alter metabolism of either imipramine or desipramine. The relative merits of single-dose predictions using total and "abbreviated" areas under the curve and concentration at 24 hours are compared. These findings demonstrate that single-dose prediction can be used as a practical therapeutic, as well as, research tool.