Plasma concentration of nortriptyline as a guide to treatment

Abstract
Summary: Blood samples were collected from forty-five patients with depression who had been taking nortriptyline for at least 14 days. At the time of blood collection the observer recorded his opinion of each patient’s response to treatment either as ‘satisfactory’ or ‘unsatisfactory’, together with any change in therapy then decided upon. The patients came from six different hospitals but all plasma nortriptyline estimations were performed at a single laboratory. No statistically significant correlation could be discerned between dose or plasma nortriptyline concentration and therapeutic response or decision to change treatment. Under the conditions of general psychiatric practice, the occasional ‘spot’ estimation of plasma nortriptyline concentrations is unlikely to be a practical guide to the nortriptyline requirements of most patients.