Skip to Content


Generic Name: naloxone (nah LOX one)
Brand Names: Evzio, Narcan

What is Evzio?

Evzio (naloxone) blocks or reverses the effects of opioid medication, including extreme drowsiness, slowed breathing, or loss of consciousness. An opioid is sometimes called a narcotic.

Evzio auto-injector is a prescription medicine used for the treatment of an opioid emergency such as an overdose with signs of breathing problems and severe sleepiness or not being able to respond.

Evzio should not be used in place of emergency medical care for an overdose.

Naloxone is also used to help diagnose whether a person has used an overdose of an opioid.

Important information

In an emergency situation it may not be possible before you are treated to tell your caregivers about your health conditions or if you are pregnant or breast feeding. Make sure any doctor caring for you afterward knows that you have received this medication.

Slideshow: Saving Lives: Best To Know Your Breast

Evzio may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

If you are using any narcotic pain medication, the pain-relieving effects of the narcotic will be reversed while you are also receiving Evzio.

Drinking alcohol can increase certain side effects of Evzio.

Before receiving Evzio

You should not receive Evzio if you are allergic to naloxone.

To make sure Evzio is safe for you, tell your doctor if you have:

  • heart disease.

It is not known whether Evzio will harm an unborn baby. Tell your doctor if you are pregnant.

It is not known whether naloxone passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

In an emergency situation it may not be possible to tell your caregivers if you are pregnant or breast feeding. Make sure any doctor caring for your pregnancy or your baby knows you have received this medicine.

How is Evzio given?

Evzio is injected into a muscle, under the skin, or into a vein through an IV. The injection may be given by a healthcare provider, emergency medical provider, or a family member or caregiver who is trained to properly give an injection.

If you are a caregiver or family member giving an Evzio injection, read all instructions when you first get this medicine. If provided, use the "trainer" device to practice giving an injection so you will know how to do it in an emergency. Ask your doctor or pharmacist if you have any questions.

Be sure you know how to recognize the signs of an opioid overdose in the person you are caring for. Overdose symptoms may include:

  • slowed breathing, or no breathing;

  • very small or pinpoint pupils in the eyes;

  • slow heartbeats; or

  • extreme drowsiness, especially if you are unable to wake the person from sleep.

Even if you are not sure an opioid overdose has occurred, if the person is not breathing or is unresponsive, give the Evzio injection right away and then seek emergency medical care.

Do not assume that an overdose episode has ended if symptoms improve. You must get emergency help after giving an injection.

Evzio injected into a muscle is given in the outer thigh. In an emergency, you may give an injection through the person's clothing.

After injecting Evzio, stay with the person and watch for continued signs of overdose. You may need to give another injection every 2 to 3 minutes until emergency help arrives. Follow all medication instructions carefully.

Each Evzio auto-injector is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting a dose.

Store at room temperature away from moisture and heat. Keep the auto-injector in its outer case until you are ready to use it. Do not use Evzio if it has changed colors or has particles in it. Call your pharmacist for new medication.

What happens if I miss a dose?

Because you will receive Evzio in an emergency situation, you are not likely to miss a dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Evzio?

Avoid leaving a person alone after giving him or her an Evzio injection. An overdose can impair a person's thinking or reactions.

Evzio side effects

Get emergency medical help if you have signs of an allergic reaction to naloxone: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Because Evzio reverses opioid effects, this medicine may cause sudden withdrawal symptoms such as:

  • nausea, vomiting, diarrhea, stomach pain;

  • fever, sweating, body aches, weakness;

  • tremors or shivering, fast heart rate, pounding heartbeats, increased blood pressure;

  • feeling nervous, restless, or irritable;

  • goosebumps, shivering;

  • runny nose, yawning; or

  • (in babies younger than 4 weeks old) seizures, crying, stiffness, overactive reflexes.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

What other drugs will affect Evzio?

Other drugs may interact with naloxone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Where can I get more information?

  • Your pharmacist can provide more information about Evzio.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Evzio only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2015 Cerner Multum, Inc. Version: 3.04. Revision Date: 2015-08-15, 2:17:37 AM.