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Generic Name: Flumazenil (FLOO may ze nil)

Medically reviewed by Last updated on Oct 8, 2020.


  • This medicine may cause seizures in some patients. Talk with the doctor.

Uses of Flumazenil:

  • It is used to reverse the effects of some drugs.
  • It is used to treat side effects after benzodiazepine (eg, alprazolam, diazepam, and lorazepam) overdose.

What do I need to tell my doctor BEFORE I take Flumazenil?

  • If you have an allergy to flumazenil or any other part of flumazenil.
  • If you are allergic to flumazenil; any part of flumazenil; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have been given a drug like alprazolam, diazepam, or lorazepam to control a life-threatening health problem like raised pressure in the head or seizures.
  • If you think there has been an overdose from taking a drug used to treat low mood (depression) like amitriptyline.

This is not a list of all drugs or health problems that interact with flumazenil.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take flumazenil with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Flumazenil?

  • Tell all of your health care providers that you take flumazenil. This includes your doctors, nurses, pharmacists, and dentists.
  • Avoid alcohol or other drugs and natural products that may slow your actions for 24 hours after getting flumazenil and until you see how flumazenil affects you.
  • You will get more alert after you get flumazenil. Sometimes, you may feel sleepy again after getting flumazenil. Avoid driving and doing other tasks or actions for 24 hours after getting flumazenil and until you see how flumazenil affects you.
  • Use with care in children. Talk with the doctor.
  • Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using flumazenil while you are pregnant.
  • Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

How is this medicine (Flumazenil) best taken?

Use flumazenil as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • It is given as a shot into a vein.
  • You will be watched closely while you receive flumazenil and for some time after your dose. Talk with your doctor.

What do I do if I miss a dose?

  • Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Shortness of breath.
  • Fast breathing.
  • A heartbeat that does not feel normal.
  • Seizures.
  • Mood changes.
  • Change in how you act.
  • Feeling agitated.
  • Change in balance.
  • This medicine may irritate the vein. If the drug leaks from the vein, it may also cause irritation around that area. Tell your nurse if you have any redness, burning, pain, swelling, or leaking of fluid where the drug is going into your body.

What are some other side effects of Flumazenil?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Dizziness.
  • Upset stomach or throwing up.
  • Blurred eyesight.
  • Dry mouth.
  • Headache.
  • Sweating a lot.
  • Feeling nervous and excitable.
  • Shakiness.
  • Not able to sleep.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Flumazenil?

  • If you need to store flumazenil at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer information use

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about flumazenil, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.