The practical significance of nortriptyline plasma control. A prospective evaluation under routine conditions in endogenous depression.

The problem of the advantage of using nortriptyline (NT) plasma level during treatment for endogenous depression has been approached. In an ordinary psychiatric department, 34 patients had their NT level checked the second week of treatment and their dosage subsequently adjusted, if it was outside the recommended therapeutic plasma range (50--150 ng/ml). A cautious dose policy led to low plasma levels followed by dose increase in about 40% of the patients. Only in a few patients was the plasma level above the upper limit. The general outcome, about 20% failures, was compatible with the best in literature. These and other results suggest that controlling the NT plasma concentration, aiming at a level of around 100 ng/ml, might offer a therapeutic advantage, but only if the department has established a therapeutic strategy that involves such a monitoring system. The therapeutic outcome was the same as or even better in the old-age group than that in patients under 65 years of age.