New developments in the therapy of intoxications

Abstract

There has been a significant evolution in the clinical management of the poisoned patient over the last decade. Interventions that were once the cornerstone of treating the poisoned patient have become passé or have come under intense scrutiny. The advent of evidence-based medicine has forced clinical scientists to re-evaluate standard therapies. Gastrointestinal decontamination with either emesis or gastric lavage was the foundation of the initial management of most poisoned patients. Examination of the published literature demonstrated that neither emesis nor lavage changed the ultimate outcome of poisoned patients, and most poison centers have abandoned their use. Even the use of activated charcoal has been questioned. A multitude of studies demonstrated that the effectiveness of activated charcoal diminished significantly 30-60 min after the ingestion of a poison. No study has demonstrated that charcoal changed patient outcome. Cathartics have been deemed to be ineffective and potentially dangerous and are never indicated. Whole bowel irrigation should not be used routinely in the management of the poisoned patient. Multiple dose activated charcoal and urinary alkalinization, commonly used to enhance the elimination of some poisons, have limited usefulness. While these 'old' and more general methods of 'detoxification' have thus failed in most cases to improve or change patient outcome, the use of more specific antidotes, tailored to the exact cause of intoxication is to be considered. Very few antidotes, however, are used on a consistent basis in the management of poisoned victims. The indiscriminate use of antidotes may even be harmful to the patient and incur an inordinate expense. In addition to the commonly known antidotes N-acetylcysteine (acetaminophen, paracetamol), naloxone (opioids) and flumazenil (benzodiazepines), new antidotes include fomepizole to treat ethylene glycol and methanol poisoning and Crotalidae Polyvalent Immune Fab (Ovine) for pit viper envenomation.