Patients who ingest toxic substances may require extracorporeal removal of the poisons or their toxic metabolites if native renal clearance is not sufficient because of acute kidney injury, acuity of symptoms, or burden of toxin. Here, a case is presented, and the literature on renal replacement therapy in the event of acute intoxication is reviewed. Extracorporeal therapy efficacy is examined in terms of the characteristics of the toxin (molecular size, charge, protein, or lipid binding); the patient (body habitus and volume of distribution); and the process (membrane effects on extraction ratios and sieving, role of blood, and dialysate flow rates). The choice of extracorporeal therapy and hemodialysis prescriptions for specific poisonings are discussed.