[Side effects of amitriptyline in relation to its plasma levels].

In a 21-day investigation in 15 patients with depression the authors investigated the incidence of undesirable side-effects in relation to plasma amitriptyline levels. The authors found the upper range of plasma concentrations when the patient's risk is minimal as regards serious undesirable complications. This upper limit is 350 micrograms/l; as compared with previous work, they consider amitriptyline levels from 150 to 350 350 micrograms/l safe and therapeutically effective. The authors consider investigation of plasma levels indicated in risk patients and in patients with an inadequate response to treatment.