Naloxone Injection

pronounced as (nal ox' one)

Brand Name(s): Narcan®, Evzio®, Zimhi, also available generically

Why is this medicine prescribed?

Naloxone injection is used along with emergency medical treatment to reverse the life-threatening effects of a known or suspected opiate (narcotic) overdose. Naloxone injection is also used after surgery to reverse the effects of opiates given during surgery. Naloxone injection is given to newborns to decrease the effects of opiates received by the pregnant mother prior to delivery. Naloxone injection is in a class of medications called opiate antagonists. It works by blocking the effects of opiates to relieve dangerous symptoms caused by high levels of opiates in the blood.

Are there other uses for this medicine?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

How should this medicine be used?

Naloxone injection comes as a solution (liquid) in vials, ampules, and in prefilled syringes to be injected intravenously (into a vein), intramuscularly (into a muscle), or subcutaneously (just under the skin). It is usually given as needed to treat opiate overdoses.

Naloxone injection may not reverse the effects of certain opiates such as buprenorphine (Belbuca, Buprenex, Butrans) and pentazocine and may require additional naloxone doses.

You will probably be unable to treat yourself if you experience an opiate overdose. You should make sure that your family members, caregivers, or the people who spend time with you know how to tell if you are experiencing an overdose, how to inject naloxone, and what to do until emergency medical help arrives. Your doctor or pharmacist will show you and your family members how to administer the medication. You and anyone who may need to administer the medication should read the instructions that come with the device and practice with the training device provided with the medication. Ask your pharmacist for the instructions or visit the manufacturer's website. In case of emergency, even a person who has not been trained to inject naloxone should still try to inject the medication.

Symptoms of an opioid overdose include excessive sleepiness; not awakening when spoken to in a loud voice or when the middle of your chest is rubbed firmly; shallow or stopped breathing; or small pupils (black circles in the center of the eyes). If someone sees that you are experiencing these symptoms, he or she should give you your first dose of naloxone into the muscle or under the skin of your thigh. The medication may be injected through your clothing if necessary in an emergency. After injecting naloxone, the person should call 911 immediately and then stay with you and watch you closely until emergency medical help arrives. Your symptoms may return within a few minutes after you receive a naloxone injection. If your symptoms return, the person should use a new automatic injection device to give you another dose of naloxone. Additional injections may be given every 2-3 minutes if symptoms return before medical help arrives.

Each single-dose injection syringe should be used only once and then should be discarded. Ask your doctor or pharmacist how to safely dispose of used syringes.

What special precautions should I follow?

Before using naloxone injection,

  • tell your doctor and pharmacist if you are allergic to naloxone injection, any other medications, or any of the ingredients in naloxone injection. Ask your pharmacist or check the manufacturer's patient information for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to tell your doctor about all the medications you are taking.
  • tell your doctor if you have or have ever had heart, kidney, or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you receive naloxone injection during pregnancy, your doctor may need to monitor your unborn baby carefully after you receive the medication.

What side effects can this medicine cause?

Naloxone injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • pain, burning, or redness at the injection site
  • hot flashes or flushing

Some side effects can be serious. If you experience any of these symptoms, get emergency medical treatment:

  • rapid, pounding, or irregular heartbeat
  • seeing things or hearing voices that do not exist (hallucinations)
  • loss of consciousness
  • seizures
  • signs of opiate withdrawal such as body aches, diarrhea, fast heart beat, fever, runny nose, sneezing, sweating, yawning, nausea, vomiting, nervousness, restlessness, irritability, shivering or trembling, stomach cramps, weakness, and the appearance of hair on the skin standing on end
  • crying more than usual (in babies treated with naloxone injection)
  • stronger than normal reflexes (in babies treated with naloxone injection)

Naloxone injection may cause other side effects. Tell your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online ( ) or by phone (1-800-332-1088).

What should I know about storage and disposal of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store naloxone injection at room temperature and away from light, excess heat and moisture (not in the bathroom). Do not freeze naloxone injection.

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website ( ) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach.

What other information should I know?

Do not let anyone else use your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

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