Poisoning and Drug Overdoses

Poisoning and Drug Overdoses

Poisoning occurs when a toxic substance enters the body in amounts harmful enough to cause physiological dysfunction or death. These substances can be accidental or intentional and include a wide variety of agents such as pharmaceuticals, chemicals, household products, pesticides, plants, and illicit drugs. The rising availability of prescription medications, recreational drugs, and industrial chemicals has contributed to an increase in poisoning incidents. Drug overdoses, whether intentional for self-harm or accidental, involve consumption of doses beyond therapeutic ranges, leading to toxic effects on multiple organ systems. These emergencies require immediate medical attention because the toxic agents can act rapidly to impair vital functions such as respiration, cardiovascular stability, and neurological integrity.

The clinical presentation of poisoning and overdoses varies widely depending on the agent involved, dose, route of exposure, and patient factors such as age and comorbidities. Common manifestations include altered mental status ranging from agitation to coma, respiratory depression or distress, cardiac arrhythmias or arrest, seizures, and metabolic disturbances such as acidosis or electrolyte imbalances. Many poisons have specific toxidromes—constellations of signs and symptoms—that guide clinicians in identifying the likely agent when history is unclear.

For example, opioid overdoses classically present with pinpoint pupils, respiratory depression, and unconsciousness, while anticholinergic poisoning may cause dry skin, dilated pupils, hallucinations, and hyperthermia. Because patients often cannot provide accurate histories, healthcare providers must rely on physical examination, clinical clues, and, when available, toxicology screening to guide diagnosis and management.