Flumazenil: Is There An Antidote For Benzodiazepine Overdose?

Flumazenil, a benzodiazepine receptor antagonist, reverses benzodiazepine overdose symptoms. It can also cause acute withdrawal in people addicted to benzodiazepines, so it’s not often recommended as an overdose treatment.

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The antidote to benzodiazepine overdose is flumazenil, a drug marketed under the brand names Romazicon, Mazicon, Lanexat, and Anexate. Flumazenil doesn’t work for everyone—it comes with many risks.

Benzodiazepines & Overdose Risk

Benzodiazepines are sedative-hypnotic medications that depress the central nervous system (CNS). They’re prescription drugs used for sedation during surgery (anesthesia), seizures, anxiety, and insomnia.

Commonly prescribed benzodiazepines are:

  • alprazolam (Xanax)
  • clonazepam (Klonopin)
  • diazepam (Valium
  • lorazepam (Ativan)
  • midazolam (Versed)

If you take high doses or regularly abuse these drugs, you risk benzodiazepine toxicity. Depressant drug overdose causes severe respiratory depression that may be fatal.

Benzodiazepine Overdose Symptoms

Benzodiazepines work on gamma-aminobutyric acid (GABA), a neurotransmitter that prevents too much brain activity. The effect of benzodiazepines is to enhance GABA, producing a sense of calm and slowing down your breathing and heart rate.

If you overdose on benzodiazepines, symptoms may include:

  • difficulty breathing
  • low blood pressure (hypotension)
  • slow or irregular heartbeat
  • loss of coordination
  • slurred speech
  • confusion

The risk of benzodiazepine overdose increases if you combine the drugs with opioids, barbiturates, or alcohol.

What Is Flumazenil?

Flumazenil is a benzodiazepine antagonist (also called a benzodiazepine receptor antagonist).

It binds to and blocks benzodiazepine receptors, preventing the drugs from affecting the brain or body. Flumazenil works as a benzodiazepine antidote because it stops overdose symptoms.

How Does Flumazenil Work?

Given as an injection in an IV infusion, flumazenil works quickly. It takes only one or two minutes to affect someone who has overdosed. Within three minutes, 80 percent of the drug should be working in your system.

Flumazenil has a short half-life (the time it takes for half of the drug to leave your system). Its effects peak after six to 10 minutes, lasting anywhere from 19 to 50 minutes in total. Depending on the severity of benzodiazepine toxicity, you may need more than one dose.

Doses are given in small amounts to prevent an adverse effect.

Research shows that flumazenil can reverse sedation, memory loss, and lack of coordination caused by benzodiazepine overdose.

Flumazenil Side Effects

Many possible side effects can occur with flumazenil. It can affect your heart, brain, and other body parts.

Flumazenil side effects may be:

  • sedation
  • irregular heart rate
  • racing heartbeat
  • slow heartbeat
  • chest pain
  • high blood pressure
  • confusion
  • dizziness
  • difficulty thinking clearly
  • shivering
  • drowsiness
  • nausea and vomiting
  • blurred vision
  • anxiety
  • panic attacks
  • injection site pain or irritation

Flumazenil Risks

Flumazenil can be safely administered to someone who has accidentally taken too much of a benzodiazepine or has difficulty reviving consciousness after surgical sedation. However, it can be life-threatening for people who struggle with substance abuse.

If someone is dependent on benzodiazepines, flumazenil can cause them to go into acute benzodiazepine withdrawal. People who misuse tricyclic antidepressants with benzodiazepines have this risk, too. The withdrawal syndrome may be intensely uncomfortable and painful.

Seizures are severe withdrawal symptoms in people addicted to benzodiazepines. Typically, benzodiazepines can treat a seizure, but if someone has taken flumazenil, the benzodiazepines will be ineffective.

Many people have died as a result of seizures triggered by the use of flumazenil.

Medical professionals don’t recommend flumazenil in most cases of benzodiazepine poisoning. It’s too risky. Healthcare professionals will only use it if the benefits outweigh the risks.

Other Treatments For Benzodiazepine Overdose

While there is no other benzodiazepine antidote, most people can recover from an overdose with time and supportive care in the emergency department.

Treatment of benzodiazepine overdose may include monitoring your heart rate and inserting a tube into your airway to improve breathing.

Death from a benzodiazepine overdose is unlikely. Fatal drug overdoses are more common when you mix benzodiazepines with other drugs like opioids. If opioids are involved, you may need different care, including naloxone, which reverses opioid overdose symptoms.

If you or a loved one are struggling with benzodiazepine drug abuse, we’re here for you. Bedrock Recovery Center offers personalized inpatient rehab programs for benzodiazepine addiction.

Through evidence-based treatment options like cognitive behavioral therapy and daily process groups, we work with you to resolve the root of addiction. Our programs nurture your physical and mental health while providing a safe space to heal.

Reach out to us today to learn more and start your recovery now.

  1. BMJ Best Practice — Benzodiazepine Overdose https://bestpractice.bmj.com/topics/en-us/343
  2. National Library of Medicine: DailyMed — Flumazenil - flumazenil injection https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=70b1aaf5-b53b-4c42-80b7-d260c4364845&type=display
  3. National Library of Medicine: StatPearls — Flumazenil https://www.ncbi.nlm.nih.gov/books/NBK470180/#:~:text=Mechanism%20of%20Action-,Flumazenil%20is%20a%20benzodiazepine%20antagonist.,of%20benzodiazepines%20to%20benzodiazepine%20receptors.
  4. National Library of Medicine: StatPearls — Benzodiazepine Toxicity https://www.ncbi.nlm.nih.gov/books/NBK482238/

Written by Bedrock Recovery Center Editorial Team

Published on: August 24, 2023

© 2024 Bedrock Recovery Center | All Rights Reserved

* This page does not provide medical advice.

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