Poisonings, adverse drug effects, and envenomations continue to be commonly encountered. Patients often present critically ill and warrant ICU admission. Many other patients who are initially stable have the potential for rapid deterioration and require continuous cardiopulmonary and neurologic monitoring. Given the potential for rapid deterioration, and because patients need continuous monitoring, ICU admission is frequently required. This article is the first of a three-part series to be published in CHEST; it discusses general management, laboratory tests, enhanced elimination, and emerging therapies. The second article will address the management of specific overdoses; the last will cover plants, mushrooms, envenomations, and heavy metals.