Naloxone Injection: Uses, Dosage, Side Effects, Precautions and Alternates

Quick overview

Naloxone Injection (naloxone hydrochloride) is an opioid antagonist given as an emergency treatment to reverse the effects of a known or suspected opioid overdose. It is supplied as a prefilled syringe or single-dose vial and is injected into the muscle or under the skin, typically in the outer thigh. It works by displacing opioids from receptors in the brain and nervous system, reversing slowed breathing and severe drowsiness. It is used in both adults and children.

What is Naloxone Injection

Naloxone is an injectable medicine used in emergencies to reverse the effects of an opioid overdose. It comes in a prefilled syringe and is injected into the muscle or under the skin of the outer thigh.

Naloxone Injection uses

• Emergency treatment of known or suspected opioid overdose, shown by slowed or stopped breathing and/or severe drowsiness or unresponsiveness
• Used in both adults and children

Benefits of Naloxone Injection

• Rapidly reverses opioid overdose
• Can restore breathing
• Reverses opioid-induced sedation
• Works against many prescription and illicit opioids
• Can be life-saving when given promptly

How Naloxone Injection works

Opioid drugs attach to certain receptors in the brain and nervous system that control pain and breathing. Naloxone works by attaching to these same receptors instead, which pushes the opioid off and blocks its effects, reversing breathing problems, severe sleepiness, and low blood pressure caused by the overdose.

Naloxone Injection dosage

Naloxone Injection is meant to be given by a caregiver or bystander, not by the person experiencing the overdose. It is intended to be given by people 12 years of age or older; younger people or those with limited hand strength may find the device difficult to use.

Inject into the outer thigh; this can be done through clothing if necessary. Place the patient on their back before injecting, then turn them onto their side (recovery position) afterward. In children under 1 year old, the caregiver should pinch the thigh muscle while giving the injection.

Get emergency medical help right away after giving the first dose, even if the person seems to wake up. Keep the person under close watch until emergency help arrives, because symptoms can return. Additional doses may be given every 2 to 3 minutes using a new syringe if the person does not respond or symptoms return. Each syringe holds only one dose and cannot be reused.

It is normal to see a drop of liquid on the needle when the cap is removed, and for some liquid to remain in the syringe after use. After giving the injection, slide the safety guard over the needle using one hand with fingers behind the needle; never use two hands or put fingers over the exposed needle. Place the used syringe in its case and give it to a healthcare provider for proper disposal, and tell them where the injection was given.

Available forms and strengths

• Prefilled syringe for intramuscular or subcutaneous injection (5 mg/0.5 mL)
• Single-dose vial for intravenous, intramuscular, or subcutaneous injection (0.4 mg/mL)

Side effects of Naloxone Injection

Common

• Nausea
• Dizziness or lightheadedness
• Increased bilirubin (a blood breakdown product) found on blood tests
• Sweating
• Fast heartbeat
• Increased blood pressure
• Feeling shaky

Serious

• Sudden opioid withdrawal symptoms: body aches, fever, sweating, runny nose, sneezing, goose bumps, yawning, weakness, shivering or trembling, nervousness, restlessness or irritability, diarrhea, nausea or vomiting, stomach cramping, increased blood pressure, increased heart rate
• In infants under 4 weeks old, sudden opioid withdrawal that may be life-threatening, with seizures, excessive crying, and increased reflexes
• Allergic reactions: skin rash, itching, hives, swelling of the face, lips, tongue, or throat
• Heart problems: low or high blood pressure, irregular or fast heartbeat, fluid buildup in the lungs, and in rare cases cardiac arrest
• Seizures (uncommon, and it's not fully clear if naloxone causes them)
• Accidental needlestick injury, which may expose a person to blood-borne infections

Warnings and precautions

• Because naloxone wears off faster than most opioids, breathing problems and severe drowsiness can return after the first dose. Always get emergency medical help right away, keep watching the person closely, and give repeat doses as needed until help arrives.
• If the overdose is caused by certain opioids like buprenorphine or pentazocine, naloxone may not fully reverse the breathing problems, and larger or repeated doses may be needed.
• In people who regularly use opioids, naloxone can cause sudden and severe withdrawal symptoms. In newborns, this withdrawal can be life-threatening if not recognized and treated quickly.
• Sudden reversal of opioid effects after surgery can cause serious heart-related problems, especially in people with existing heart conditions.
• After use, the needle stays exposed until the safety guard is slid over it, so there is a risk of an accidental needlestick. Learn how to use the device safely before an emergency happens.
• Naloxone should only be used in pregnant women if clearly needed. Opioid overdose is dangerous for both mother and baby, so treatment should not be withheld out of concern for the baby. If used, the unborn baby should be checked by a doctor afterward because withdrawal symptoms could occur.
• It isn't known whether naloxone passes into breast milk, but it is unlikely to affect a breastfed baby.
• No routine emergency dose adjustment is generally required for kidney function. Older adults may process naloxone differently if they have reduced liver, kidney, or heart function, which can lead to higher levels of the drug in the body.
• Naloxone does not reverse an overdose caused by alcohol or other non-opioid substances, but giving naloxone to someone who has not taken opioids is unlikely to cause harm.
• Do not drive after an opioid overdose or naloxone administration; emergency medical evaluation is needed.

Storage

• Store in the outer case provided to protect from light
• Store below 77°F (25°C); brief exposure up to 104°F (40°C) is allowed
• Do not freeze or expose to excessive heat above 104°F (40°C)
• Periodically check the solution through the viewing window; if discolored (yellow or brown), cloudy, or containing particles, replace with a new one
• Replace before the expiration date
• Keep out of the reach of children
• Dispose of expired or used syringes by taking them in their case to a healthcare provider or hospital emergency room

When to see a doctor

• Get emergency medical help immediately after giving the first dose of naloxone, even if the person seems to wake up, because naloxone does not replace emergency medical care.
• If an accidental needlestick happens while giving the injection, seek medical attention right away because of the risk of blood-borne infections.
• If the person's symptoms come back or they do not respond within a few minutes, give another dose and keep watching them closely until help arrives.

Alternatives

• Naloxone nasal spray
• Nalmefene nasal spray
• Nalmefene injection