Nortriptyline Plasma Levels and Subjective Side Effects*

Abstract
Nortriptyline plasma levels and the incidence and severity of the common subjective side effects of the tricyclic antidepressants were determined in 26 patients during six weeks of treatment with nortriptyline. The total corrected (treatment minus pre-treatment) score of the eight side effects most independent of the severity of depression correlated (0 · 60) with the nortriptyline plasma level. Increased perspiration (o · 59) and dry mouth (o · 54) were the individual corrected side effects which most consistently correlated with the plasma level. These subjective side effects may serve as clinically useful guides to dosage adjustments during treatment, though their value is limited by the magnitude of the correlations and the need to correct for their presence prior to treatment.