Naloxone (Injection)

Naloxone is an injection that reverses or blocks the effects of opioid medication. This drug is used in the treatment of a suspected narcotic overdose.


Naloxone is an injection that is used in the treatment of opioid emergencies such as a possible overdose or overdose of a narcotic medication. Some symptoms and signs of an opioid emergency include breathing problems (which can range from shallow or slow breathing to no breathing), slow heartbeat, extreme sleepiness, or not able to respond. You can only obtain this medication via a prescription from your doctor. It is available in the dosage form of solution for injection.

Condition(s) treated

  • Narcotic overdose

Type of medicine

  • Solution for injection

Side effects

Along with the intended effects of this medication, its use can produce some unwanted side effects. You may not suffer from all of these side effects, but if you do, you may need to seek medical attention.

Check with your doctor or healthcare team immediately if you suffer from any of the following side effects whilst using naloxone.

Incidence not known

  • Pounding, fast, or irregular pulse or heartbeat

You may suffer from other side effects that are not listed above. You should seek advice from your doctor if you notice anything unusual.


Proper Use

A family member or home health caregiver will give you or your child this medication. It's given as a shot into a muscle or under your skin. This medication typically comes alongside instructions and a training device. You should allow your family member or health caregiver to follow and read the directions carefully. Seek advice from a doctor if you have any questions.

To use:

This medication is available as an autoinjector and can only be used once. It's available in two dosage strengths: 0.4 milliliter (mL)/0.4 milligram (mg) autoinjector or 0.4ml/ 2 mg autoinjector.

It also contains printed instructions on the device label and a speaker that provides you with electronic instructions which guides you through each part of the injection.

Inject the medication into the outer thighs, via clothing, if required. If you're giving this medication to a child younger than one-year-old, you should pinch the thigh muscle while giving the medication.

Don't use the medication if it is discolored, cloudy, or has large particles in it.

Don't remove the red safety guard until it's ready for use.

After giving the first dose of this drug to the patient, seek emergency medical help immediately.

Closely watch the patient for symptoms and signs of opioid emergency as it may return after several minutes.

Give a new naloxone injection every two to three minutes if symptoms return and monitor the person until emergency help is received.


The final dose of this medication will depend on a number of different factors. Your doctor will consider your weight, height, and age, any other medications you are taking to treat any other medical conditions you suffer from. They will also consider the strength of the medication, your reaction to the first dose and more. The following doses are guidelines.

For injection dosage form for treatment of opioid emergency:

Adults and children: 2 or 0.4 milligrams (mg) injected into a muscle or under the skin.


Drug interactions can occur with this medication. These can cause severe side effects or reduce the effectiveness of the drug in treating an opioid emergency. To help limit the risk of interactions occurring, you should give your doctor a complete list of all the current and past medications you are taking. This needs to include vitamin supplements, prescription/nonprescription drugs, and herbal products. You should also make your healthcare professional aware of any other medical conditions you may suffer from. In most cases, your doctor will avoid treating you with this drug when necessary, but in some circumstances, it may be unavoidable.

The use of this medication alongside any of the following medications is not typically recommended, but in some cases, it may be required. If you are given both medications together your doctor may change the dose or frequency in which you use either medication.

  • Morphine Sulfate Liposome

The use of this medication alongside any of the following medications can increase your risk of certain side effects, however, the use of both drugs may be the best treatment plan for you. Your doctor may alter the dose or frequency in which you use either medication.

  • Yohimbine

Let your doctor know if you are taking any of the following drugs as they can produce "moderate to severe" interactions.

  • Nalbuphine

This list is not complete, which is why is it important that your doctor or healthcare team are aware of all medications you are currently taking.

Other Interactions

Some medications cannot be used at the time as consuming food or certain types of food as this could increase your risk of an interaction. The use of tobacco or alcohol with some medications can also cause interactions. You should discuss with your doctor about the use of this drug alongside alcohol, food or tobacco.

Other Medical Problems

The presence of other medical conditions could affect the proper use of this medicine. Ensure you let your doctor know about any other medical conditions you may suffer from including:

  • Heart disease


Before you take a medication there are a number of different factors you need to be aware of and take into account alongside the advice of your doctor. Some of these considerations are listed below. Make sure you read them carefully.


It's important to make your doctor aware if you have ever suffered from an allergic reaction to this medication or any other medications. You should also make your health care team aware of any other allergies you may suffer from including animals, dyes, preservatives, and foods.

Pediatric population

Appropriate studies conducted to date have not indicated a pediatric-specific problem that could limit the effectiveness of naloxone injection in children.

Geriatric population

Appropriate studies conducted to date have not indicated a geriatric-specific problem that could limit the effectiveness of naloxone injection in the older population. However, older patients are more likely to have age-related liver, kidney, or heart problems, which could require a degree of caution and an adjustment in the dose for those who are receiving naloxone injection.

Use in pregnancy and breastfeeding

This drug is under FDA pregnancy category C. It is unknown whether this medication can harm an unborn child. You should tell your doctor if you are pregnant.

It's unknown whether naloxone can pass into breast milk or if it could harm a nursing child. Let your doctor know if you are currently breastfeeding a child.

In an emergency situation, you may not be able to tell your caregivers if you are breastfeeding or pregnant. Ensure any doctor caring for your pregnancy or your baby knows you have received this drug.

This medicine should be given immediately after a known or suspected overdose of a narcotic or opioid medication. This is to prevent a serious condition known as central nervous system or respiratory depression.

Severe opioid withdrawal symptoms can happen suddenly after receiving this medication. This could include a fever, body aches, sweating, sneezing, runny nose, goose bumps, weakness, yawning, shivering or nervousness, trembling, restlessness or diarrhea, irritability, vomiting or nausea, stomach cramps, increased blood pressure and fast heartbeat.


Naloxone should be stored in a closed container and kept away from moisture, heat, and light. Do not let this medication freeze. You should ensure it is kept out of the reach of children. Don't use or keep medication that is no longer required or out of date. You should ask your healthcare professional how to dispose of any medication you don't use.


When used correctly this drug is successful in the treatment of opioid or narcotic overdoses. Due to the large number of drugs this injection can interact with, it's important to make people aware of all medications you are currently consuming. This drug will be given by a home caregiver or a family/friend in an emergency situation. If possible, you should let them know if you are currently breastfeeding or possibly pregnant. However, in an emergency situation, you may be unable to do so. The safety and efficacy of this drug have not been established in very small children.

Naloxone is injected under the skin or into a muscle, or into a vein via an IV. It's important you allow family or a home caregiver to read the instructions that come with this injection. If you require any further information about the practical uses of this medication or you have any more questions, then contact your local healthcare professional or doctor for further advice.