Summary

• Benzodiazepines (BZDs) are the most commonly prescribed medications for anxiety, sedation, and sleep. Overdose can be intentional in suicidal patients, accidental in combination with other CNS depressants such as alcohol and opioids and in older people, and occasionally by medication error.
• The key feature is excessive sedation with unremarkable vital signs and anterograde amnesia. Larger doses can cause coma and respiratory depression.
• Treatment of overdose is by symptom management, not by quantitative assay. Acute management consists of maintaining airway, respiration, and haemodynamic support while excluding other diagnoses. Assisted ventilation may be necessary.
• Death is uncommon. Most deaths from BZD overdose are from respiratory depression as a result of mixed overdoses with BZD and other respiratory depressants, particularly alcohol.
• The BZD antagonist flumazenil can be used in first-time or infrequent BZD users to reverse CNS depression. It is contraindicated in BZD-dependent patients because of the risk of provoking seizures. The risks associated with its use often outweigh the benefits.