Flumazenil

Liverpool Hospital Emergency Department

Indications: Competitive antagonist at BDZ receptors. Duration of action 45-60 minutes  therefore BDZ half-life exceeds this. 

  • Generally, NOT recommended in acute benzodiazepine overdose as it may  precipitate seizures
  • Benzodiazepine overdose is rarely severe enough to require significant  intervention and toxicity is mild 

It can be considered in benzodiazepine naïve patients who have been  exposed to a toxic dose – for example paediatric patients with accidental  ingestion or to reverse iatrogenic procedural sedation. 

Formulation: 

  • IV vials 500mcg/5mL 

Dosage and Administration:  

  • It should only be given in a critical care setting
  • Bolus:
    • Adult: 1mL to 2mL (0.1mg to 0.2mg) IV Bolus every 60 seconds repeated till  clinical effect (Maximum 2mg cumulative, if no clinical effect to consider  other causes)
    • Children: 5mcg/Kg IV Bolus every 60 seconds repeated till clinical effect.  (Maximum 8 Doses)
  • Infusion:
    • Dilute 25mL (5 Ampoules = 2.5mg) in 25mL of 0.9% Sodium Chloride to make  a 2.5mg/50mL syringe. (50mcg/mL) 
  • Start at 0.1 – 0.5mg/hour titrated to effect. 

Side Effects: 

  • Benzodiazepine withdrawal syndrome: agitation / tachycardia / seizures o Seizures 

Pit Falls 

  • Avoid in seizure disorder / ingestion of proconvulsant drugs / benzodiazepine  dependence / suspicion of TCA overdose