NO EFFECT OF AMITRIPTYLINE ON LITHIUM DISPOSITION IN DEPRESSIVE PATIENTS

There are a number of non-psychotropic and psychotropic drugs that sig nificantly interact with lithium. Some of these interactions are benef icial. In approximately 60% of depressive patients, in whom convention al treatment has failed, the combination of lithium and antidepressant drugs proves successful where neither drug was effective alone. The a im of our study was to investigate the effect of amitriptyline on lith ium disposition in depressive patients on combined lithium - amitripty line therapy, both after a single oral dose and at the steady state. A ll patients who participated in the study met DSM-III-R criteria: one group of seven patients was on lithium monotherapy, while the other gr oup of six patients was on combined lithium - amitriptyline therapy. S erum lithium concentrations were determined by flame emission spectros copy. Both serum levels and pharmacokinetics of lithium were statistic ally compared between these two groups of patients. The obtained resul ts indicate that combined lithium - amitriptyline therapy does not mod ify serum concentrations and pharmacokinetics of lithium, both after s ingle and repeated doses (at the steady state) in depressive patients.