Abstract
An 83-year-old patient suffering from a depressive episode was treated with a combination
of clomipramine and fluoxetine. As no marked improvement was observed and cardiac
side-effects were observed, a blood sample was taken for therapeutic drug monitoring.
The result showed that the concentrations of clomipramine and desmethylclomipramine
were very high (i. e. in the subtoxic range). A metabolic interaction was suspected
and both antidepressants were immediately discontinued. Over time, concentrations
of clomipramine and its metabolite decreased slowly and, simultaneously, the mood
improved and side-effects disappeared. When clomipramine and desmethylclomipramine
concentrations reached the lower limit of the optimal therapeutic range, monotherapy
was restarted with clomipramine, and the patient improved enough to be discharged
from the hospital.
