We recommend a toxicodynamic approach to the management of the poisoned patient. We define the period between ingestion and onset of toxic manifestations (clinical or laboratory) as the preclinical phase, during which the management of the patient necessarily depends solely on the history of ingestion and the predicted toxicity. In the toxic phase during which the patient shows clinical or laboratory evidence of toxicity, the history, clinical status (signs, symptoms, drug levels, laboratory parameters), and toxicodynamics should guide the therapy. In the resolution phase, when the patient shows clinical improvement and declining drug levels, treatment should be based on clinical status. Gastrointestinal decontamination is critical in the first two phases and may be of value during the resolution phase until the body drug burden declines to safe levels. We recommend an aggressive approach to gastrointestinal decontamination, especially in the preclinical phase. With a history of a potentially toxic ingestion of an absorbable drug, an observation period until passage of a charcoal-laden stool should be achieved before discharge of the patient.