Comparison of the effects of maprotiline (ludiomil) and clomipramine (anafranil) on serotonin uptake and tryptophan-binding in plasma.

The influence of maprotiline or clomipramine on plasma tryptophan-binding and brain tryptophan was studied in rats. Neither compound altered tryptophan-binding nor brain tryptophan levels after acute of chronic treatment. In a comparative study maprotiline and clomipramine were administered to healthy volunteers for 4 days and the concentrations of total and free tryptophan in plasma were determined. Serotonin uptake was also measured in the platelets from these subjects. Maprotiline treatment did not inhibit serotonin uptake nor did it have any influence on plasma tryptophan binding. Clomipramine also had no influence on plasma tryptophan-binding but strongly inhibited serotonin uptake into platelets. These results confirm the earlier observation that maprotiline has no influence on serotonin uptake and can be clearly distinguished from clomipramine.