Antidepressants, especially amitriptyline, are among the most frequent drug classes involved in intoxications. Despite its small molecular weight, amitriptyline is not considered to be eliminated by extracorporeal treatment methods due to its high protein binding and large volume of distribution. New high cut-off dialysers have so far not been used for removal of amitriptyline. We report two cases of amitriptyline poisoning in which we measured the amitriptyline elimination using extended high cut-off (HCO) dialysis. Despite dialyser clearances of 33 and 58 mL/min, resulting in the reduction of initial serum concentrations by ∼30%, only 211 and 920 µg of amitryptilin, respectively, (<3% of the ingested amount) could be recovered in the total collected dialysate. Hence, due to the high volume of distribution of amitriptyline, even HCO dialysis does not contribute substantially to the extracorporeal removal of amitryptilin.
Keywords: acute interstitial nephritis; antidepressants; proton pump inhibitors.