Summary
20 routine patients with endogenous depression were investigated in a kinetic and 4 week treatment study. Steady-state plasma nortriptyline concentrations above 200μg/L were associated with a highly significant poorer therapeutic outcome.
The correlations between the 24, 48 and 72 hour concentrations and steady-state concentration were very good (r = 0.81, 0.97, 0.94; p < 0.0001) and better than the correlation between half-life and steady-state (r = 0.65; p < 0.01). The Spearman rank correlations (Rs) between amelioration of depression measured by the Hamilton Rating Scale (HRS) and the 24, 48 and 72 hour concentrations were highly significant (Rs = 0.74, 0.79, 0.79; p < 0.001) but for half-life (Rs = 0.33) the correlation was not significant.
The single 48 hour plasma nortriptyline concentration following a single oral dose is recommended as a reliable simplified monitoring test suitable for a busy clinic. The test is useful for dosage adjustment to maximise antidepressant action and minimise toxicity. A tentative dosage adjustment schedule for individualising antidepressant treatment with nortriptyline based on the 48 hour or the 24 hour plasma concentration is proposed.
Similar content being viewed by others
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Montgomery, S.A., McAuley, R., Montgomery, D.B. et al. Dosage Adjustment from Simple Nortriptyline Spot Level Predictor Tests in Depressed Patients. Clin-Pharmacokinet 4, 129–136 (1979). https://doi.org/10.2165/00003088-197904020-00005
Published:
Issue Date:
DOI: https://doi.org/10.2165/00003088-197904020-00005