Saliva secretion following long-term antidepressant treatment with nortriptyline controlled by plasma levels

Eight patients undergoing antidepressant therapy with nortriptyline for 1--4 years were investigated. The period of the investigation was 7 weeks and included a 2-week placebo period, blind for the patients. Total saliva secretion measurement, the nortriptyline plasma level, and signs and symptoms of depression and side effects were obtained once a week during the study. The results of the investigation were: (1) long-term treatment with nortriptyline is followed by hyposecretion or xerostomia, (2) the reduction of the secretion is reversible, (3) re-establishment of treatment with dosage leading to the same serum level of nortriptyline is immediately followed by a drop in saliva secretion, and (4) the changes in salivary secretion are useful as an indicator of side effects. The practical importance of the investigation is discussed.