The clinical consequence of any excess dose of a drug, e.g., of a self-administered, potentially lethal dose of a drug of abuse, an antidepressant, a nonnarcotic pain reliever, or other medication. Drug overdose may be unintentional or deliberate. When such a dose results in coma or death, the person is said to have OD'd (overdosed).

PATIENT CARE
Emergency department personnel assess the patient's airway, breathing, circulation, level of consciousness, and vital signs, and try to ascertain (from the patient or significant others) what drug was taken, how much, when, and by what route. Blood and urine (and when it becomes available, emesis) are sent to the laboratory for toxicology screening to aid in identifying specific substances.

If the drug was administered by inhalation or parenterally, or if time lapse has allowed for absorption, an intravenous site is established, and fluid is administered as prescribed. If the patient is unconscious on admission, he will be given a narcotic antagonist, a bolus of 50% dextrose in water, and 50 to 100 mg of thiamine routinely to reverse rapidly the potential effects of opiates or low blood sugar. Depending on the patient's response to the drug's actions (such as central nervous system depression or stimulation, respiratory depression, cardiac arrhythmias, or renal failure), emergency department personnel provide necessary supportive therapies (such as airway intubation and ventilation), activated charcoal, or bowel irrigation. Because absorption rates vary and may fluctuate, the patient requires frequent reassessment with immediate intervention as appropriate.

The possibility of attempted suicide should be considered in any case of drug overdose. A psychiatric history is obtained, with any history of depression noted. Suicide precautions are established to protect the patient from further self-injury. Psychological or psychiatric follow-up is initiated for overdose resulting from depression or suicidal ideation. Drug counseling and rehabilitation may also be needed.