Reviewed on 12/15/2021

What Is Flumazenil and How Does It Work?

Flumazenil is a prescription medication used as Reversal of Conscious Sedation and General Anesthesia and as treatment of Benzodiazepine Overdose.

  • Flumazenil is available under the following different brand names: Romazicon

What Are Dosages of Flumazenil?

Adult and Pediatric dosage

Injectable solution

  • 0.1mg/mL

Reversal of Conscious Sedation and General Anesthesia

Adult dosage

  • 0.2 mg IV over 15 sec
  • If after 45 seconds no response, administer 0.2 mg again over 1 minute, may repeat at 1-minute intervals; not to exceed 4 doses (1 mg)
  • If re-sedation occurs, may repeat doses at 20-minute intervals; not to exceed 1 mg/dose or 3 mg/hour

Benodiazepine Overdose

Adult dosage

  • 0.2 mg IV over 15-30 seconds
  • If no response after 30 seconds, administer 0.3 mg over 30 seconds 1 minute later; if no response, repeat dose of 0.5 mg IV over 30 seconds at 1-minute intervals to max cumulative dose of 3 mg/hours
  • in the event of re-sedation, may repeat dose at 20-minute intervals if needed; not to exceed 1 mg (administered as 0.5 mg/min) administered at any one time and no more than 3 mg/hour
  • Rarely patients may require titration up to total dose 5 mg; if no response after 5 minutes, sedation is unlikely to be secondary to benzodiazepines

Pediatric dosage

  • Initial dose: 0.01 mg/kg IV x1 dose over 15 seconds
  • May repeat after 45 seconds and then every minute; not to exceed 4 doses for a maximum 0.05 mg/kg or 1 mg, whichever is lower

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."


About how much does an adult human brain weigh? See Answer

What Are Side Effects Associated with Using Flumazenil?

Common side effects of Flumazenil include:

  • headache, 
  • dizziness, 
  • nausea, 
  • vomiting, 
  • increased sweating, 
  • flushing (sudden warmth, redness, or tingly feeling), 
  • vision problems, and
  • pain at the injection site

Serious side effects of Flumazenil include:

  • hives, 
  • difficulty breathing, 
  • swelling of the face, lips, tongue, or throat, 
  • weak or shallow breathing, 
  • ongoing drowsiness, 
  • confusion, 
  • agitation, 
  • tremors
  • dizziness, 
  • chest pain, 
  • severe dizziness, 
  • rapid pulse
  • fast or pounding heartbeats, and 
  • lightheadedness

Rare side effects of Flumazenil include:

  • none 
This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Flumazenil?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them.  Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first

  • Flumazenil has severe interactions with no other drugs.
  • Flumazenil has serious interactions with no other drugs.
  • Flumazenil has moderate interactions with the following drugs:
  • Flumazenil has minor interactions with no other drugs. 

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drugs interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use.  Keep a list of all your medications with you, and share this information with your doctor and pharmacist.  Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns.

What Are Warnings and Precautions for Flumazenil?


  • Hypersensitivity to flumazenil or benzodiazepines
  • Possible concomitant: Cyclic antidepressant overdose
  • Chronic benzodiazepine use; patients receiving a benzodiazepine for life-threatening condition (eg, intracranial pressure control, status epilepticus

Effects of drug abuse

  • None

Short-Term Effects

  • See “What are Side Effects Associated with Using Flumazenil?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Flumazenil?”


  • Head trauma
  • History of seizures
  • Chronic alcoholism
  • Not for reversal of respiratory depression (need to establish an airway, assist ventilation, and continue to observe patient)-monitor for return of respiratory depression/sedation
  • May not reverse amnesia
  • May cause CNS depression and impair ability to perform hazardous tasks
  • Re-sedation occurs frequently in patients who have received a large single dose or cumulative dose of a benzodiazepine administered along with a neuromuscular blocker and multiple anesthetic agents
  • Agitation produced in some patients
  • Patients rarely seize with 0.2 mg dose
  • If seizure after flumazenil, recommend valium 20-30 mg, then immediately to barbiturates
  • Use caution in patients with head injury
  • Use caution in patients with hepatic dysfunction
  • Use caution in patients with panic disorder
  • Unmasking of seizures, precipitation of benzodiazepine withdrawal
  • Not for diagnosis of benzodiazepine-induced sedation

Pregnancy and Lactation

  • Use with caution in pregnancy if the benefits outweigh the risks. 
  • Excretion in milk is unknown; use with caution. 


Digestive Disorders: Common Misconceptions See Slideshow
Medscape. Flumazenil.


Health Solutions From Our Sponsors