Flumazenil Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Important information

  • Contra-indicated in patients being given benzodiazepines for the treatment of a potentially life-threatening condition (eg. increased intracranial pressure or status epilepticus)
  • See Monitoring requirements below

Available preparations

Anexate 500microgram per 5mL ampoule

Reconstitution

Already in solution

Draw up using a 5 micron filter needle

Infusion fluids

Sodium chloride 0.9% or Glucose 5%

Methods of intravenous administration

Bolus intravenous injection (preferred method)

  • Administer initial dose over 15 seconds
  • Consider slower rate of administration for patients on long term and/or high dose benzodiazepines (ref 1)

Continuous intravenous infusion

  • Dilute to any convenient volume of infusion fluid (ref 1)
  • For example: 500 micrograms (5mL) in 50mL (ref 1)
  • Rate of infusion then titrated according to response

Dose in adults

IMPORTANT: If no clear effect on awareness and respiration is obtained after repeated dosing, consider other causes for intoxication

Reversal of sedative effects of benzodiazepines in anaesthesia and clinical procedures

  • Initially, 200 micrograms over 15 seconds.
  • If necessary further doses of 100 micrograms can be given at 60 second intervals
  • Usual dose range 300 to 600 micrograms.
  • Maximum total dose 1mg per course

Reversal of sedative effects of benzodiazepines in Intensive Care

  • Initially, 300 micrograms over 15 seconds
  • If necessary further doses of 100 micrograms can be given at 60 second intervals
  • Maximum total dose 2mg per course
  • If drowsiness recurs after initial doses
    • Give an infusion of 100 to 400 micrograms per hour
    • Rate of infusion then titrated according to response
    • Alternatively, give 300micrograms as an intravenous injection, adjusted according to response
    • The infusion should be interrupted every six hours to check whether re-sedation occurs (ref 1)

In situations of poisoning or overdoses

  • Higher doses, or different intervals may be recommended by Toxbase, or by National Poisons Information Centre

Renal impairment

  • No dosage adjustment is necessary

Hepatic impairment

  • Careful titration of dosage is recommended in patients with impaired hepatic function

Monitoring

  • Monitor for signs of resedation (for up to 4 hours (ref 2))- flumazenil is a short-acting agent. Repeat doses may be necessary- benzodiazepine effects may persist
  • Monitor for withdrawal symptoms from benzodiazepines, especially if high doses or long-term exposure

Storage

Store below 250C

Do not refrigerate or freeze

References

Anexate SPC December 2020

1: Injectable Medicines guide, downloaded from Medusa 10/04/2025

2. Toxbase, accessed online 10/04/2025

Therapeutic classification

Benzodiazepine antagonist