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 central nervous system (CNS) depressants, such as alcohol and opioids, and in older people; and occasionally by medication error. Older people, who commonly have diminished drug clearance and polypharmacy, are at especially high risk of overdose.
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 hemodynamic 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 and opioids.
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.
Benzodiazepine (BZD) overdose occurs when excessive amounts of BZD medications are taken. Commonly known as minor tranquilizers or sleeping pills, BZDs are prescribed for sedative, anxiolytic, hypnotic, and anticonvulsant purposes. BZDs are also widely abused. Acute overdose is characterized by excessive sedation with impaired mental status, and diminished postural stability and reflexes. Although BZDs are relatively safe medications, acute overdose may induce respiratory depression resulting in coma and uncommonly death. Diagnosis is suggested by the history and by exclusion of other etiologies. Chronic overuse increases the risk of many other pathologies.
History and exam
Key diagnostic factors
- impaired mental status
- drowsiness, slurred speech, ataxia
- respiratory depression
Other diagnostic factors
- decreased deep tendon reflexes
- paradoxical stimulation
- history of illicit drug or alcohol use
- drug administration error
- drug interaction
- biogenetic susceptibility
- history of benzodiazepine (BZD) use
- history of polydrug or unknown substance ingestion
- suicidal ideation or behavior
- older age
1st investigations to order
- pulse oximetry
- serum chemistry panel with blood glucose
- serum ethanol
- urine toxicology screen
- flumazenil trial
Paul M. Gahlinger, MD, PhD, MPH
Paradise Medical Group
PMG declares that he has no competing interests.
Robert S. Hoffman, MD
Associate Professor Emergency Medicine and Medicine
Departments of Emergency Medicine and Medicine (Clinical Pharmacology)
NYU Medical Center
RSH declares that he has no competing interests.
Laurie Prescott, MD, FRCP (Lond), FRCP (Edin), FFPM, FRSE
Emeritus Professor of Clinical Pharmacology
University of Edinburgh and Western General Hospital
LP declares that he has no competing interests.
Ruben Thanacoody, MD, FRCP (Edin)
Consultant Physician/Honorary Senior Lecturer
Regional Drugs and Therapeutics Centre
RT declares that he has no competing interests.
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