History and exam
Key diagnostic factors
common
impaired mental status
Impaired attention or memory, especially the loss of anterograde memory. Patient should be asked about recent events since exposure, such as who brought them to hospital and how. More subtle signs of impaired mental status include inappropriate behavior or judgment, and labile mood.
drowsiness, slurred speech, ataxia
BZDs cause central nervous system inhibition and patients present with features similar to intoxication.
uncommon
coma
Large doses can cause coma.
respiratory depression
Very uncommon with isolated BZD ingestion; common when combined with other agents.
Other diagnostic factors
common
decreased deep tendon reflexes
As a central nervous system sedative, BZD overdose can produce diminished deep tendon reflexes or, less commonly, hyperreflexia from paradoxical excitation. Either response can contribute to ataxia, and is useful in assessing the central nervous system.
uncommon
nystagmus
Pathological nystagmus is the result of damage to one or more components of the vestibular system, including the semicircular canal, otolith organs, and the vestibulocerebellum. While BZDs do not specifically impair the vestibular apparatus, they may cause diminished function as a result of generalized central nervous system impairment, including the vestibulocochlear nerve.[35]
paradoxical stimulation
Uncommonly, patients who have hyperactive, aggressive, or other psychiatric disorders may be excessively agitated.
Risk factors
strong
depression
Patients should be asked about depression or history of depression and suicidal ideation.
history of illicit drug or alcohol use
This leaves the patient at risk of both accidental and deliberate overdose.
Many patients who are dependent on opioids also use benzodiazepines (BZDs) regularly, and this increases the risk of overdose of both drugs.[16][17] Patients who use drugs of abuse or who are dependent on alcohol often use drugs in combination, including BZDs, and may have a history of depression or suicidal attempts.
drug administration error
Particularly common in patients who self-medicate.[2] May also occur in hospital settings.
comorbidity
Overdose is more likely with increasing age and decreased liver function.
history of benzodiazepine (BZD) use
BZDs may have been prescribed for a variety of conditions such as anxiety and back pain.
history of polydrug or unknown substance ingestion
Most common substances include alcohol, opioids, and antihistamines such as diphenhydramine.
suicidal ideation or behavior
Recent life events, previous suicide attempts or ideation, and physical signs of previous episodes, such as slash marks, should be sought.
older age
Older people, who commonly have diminished drug clearance and polypharmacy, are at especially high risk of overdose.
weak
drug interaction
Not likely except with recreational coingestions, particularly alcohol and other central nervous system depressants.[18]
biogenetic susceptibility
The risk is largely unknown, although considerable individual variation suggests possible genetic predisposition to overdose.
Use of this content is subject to our disclaimer