Benzodiazépines
Clinical features: correlate poorly to benzodiazepine levels
Onset within 1 -2 hours
Ataxia, lethargy, slurred speech and reduced GCS. Profound coma is rare except with alprazolam or in mixed ingestions.
Apnoea indicated airway obstruction
Large ingestions can rarely cause hypothermia, bradycardia and hypotension.
Resolution of CNS depression occurs within 12 hours (unless elderly or co-morbidities), ataxia will persist for longer and your patient may be a falls risk.
Antidote
Controversial – should be used with caution.
Flumazenil is a competitive benzodiazepine antagonist. Indications include:
Reversal of conscious sedation (i.e. Iatrogenic over sedation)
Accidental paediatric ingestion
Diagnostic tool to avoid further investigation
Management of airway and breathing when resources are not available to safely intubate and ventilate the patient.
The downside to giving flumazenil is the risk or precipitating a toxidrome or a seizure in someone who has either taken a mixed overdose or has a history of epilepsy or chronic benzodiazepine use. If the patient has a seizure you are now unable to give a benzodiazepine to terminate the seizure.