Barbiturates have the highest morbidity and mortality of the sedative-hypnotics. Pure benzodiazepine ingestion usually causes little more than sedation and ataxia. Pure benzodiazepine very rarely result in death. Death from sedative-hypnotics results from respiratory arrest. The physical exam should focus on the vital signs and the neurologic and cardiopulmonary status.
Mild toxicity resembles ethanol intoxication.
Severe respiratory depression is more likely to occur when the sedative-hypnotic is ingested with other CNS depressants. Mild intoxication is characterized by ataxia, incoordination, nystagmus, slurred speech and altered level of consciousness. Moderate poisoning leads to respiratory depression and hyporeflexia. Severe poisoning leads to flaccid, areflexic coma, apnea, and hypotension. Occasionally, hyperreflexia, rigidity, clonus and Babinski signs are present.