[The problem of hemoperfusion in poisonings: ineffectiveness in maprotiline poisoning]

A case of self-poisoning with maprotiline presenting with coma stage III was treated by resin hemoperfusion for 9 hours using an XAD-4 resin cartridge. Plasma levels of about 800 ng/ml maprotilin were initially found. After 5 hours of hemoperfusion progredient clinical improvement was noticed without decreasing tendency of the blood drug levels. The theoretical extraction efficiency calculated from the maprotiline blood levels and the perfusion rate yielded 50 mg for maprotiline and 16 mg for desmethylmaprotiline and was in good agreement with 60.5 mg of maprotiline and 17.3 mg of desmethylmaprotiline recovered from the resin cartridge at the end of the hemoperfusion. The in vitro binding capacity for maprotiline was estimated to be 230 mg per g of resin. These results demonstrate that XAD-4 resin efficiently binds maprotiline. However, because of the very low blood concentrations due to the large volume of distribution, whole body concentrations are minimally affected by resin hemoperfusion. Main complications consisted in thrombocytopenia extending over 24 hours after stopping hemoperfusion, anemia, a short initial decrease of blood pressure and an episode of premature ventricular beats.