naloxone

Generic Narcan

Used for Opioid Overdose

Naloxone is a life-saving medication that's used to reverse the effects of an opioid overdose. This medication can help a person's breathing return to normal in as quickly as 2 to 3 minutes. The effects of naloxone only lasts 30 to 90 minutes, so it's important for a person who's experiencing an opioid overdose to get medical help right away. Naloxone comes in 2 different forms, a nasal spray (Kloxxado, Narcan, and generic) and auto-injector (Zimhi). You can get naloxone without a prescription.

Reviewed by:

Ally Tsai, PharmD

Connie Zheng, PharmD

Last reviewed on November 3, 2022

What is Naloxone?

What is Naloxone used for?

Emergency treatment of opioid overdose in children and adults
Raising blood pressure in the case of septic shock - naloxone IV injection only
Post-surgery slowed breathing caused by opioids - naloxone IV injection only

How Naloxone works

When a person takes an opioid, the opioid turns on certain receptors in the body and help bring pain relief. But some of these receptors also control breathing. So when there's too much opioids in the body, a person's breathing can slow or stop.

Naloxone is an opioid antagonist. It works by pushing the opioids out of the opioid receptors. In doing so, naloxone reverses the symptoms of an opioid overdose, such as slowed breathing, extreme sleepiness, and low blood pressure.

Are you looking for information on naltrexone (Vivitrol) or buprenorphine/naloxone (Suboxone) instead?

Drug facts

Common Brands	Narcan, Kloxxado, Zimhi
Drug Class	Opioid antagonist
Controlled Substance Classification	Not a controlled medication
Generic Status	Lower-cost generic available
Availability	Prescription or over-the-counter

Common Brands

Narcan, Kloxxado, Zimhi

Drug Class

Opioid antagonist

Controlled Substance Classification

Not a controlled medication

Generic Status

Lower-cost generic available

Availability

Prescription or over-the-counter

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Side effects of Naloxone

The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.

Common Side Effects

Naloxone nasal spray (Narcan, Kloxxado, generic naloxone):

Temporary higher blood pressure
Headache
Dry nose
Nasal congestion
Swollen or inflamed nose
Nose pain

Naloxone auto-injector (Zimhi)

Nausea
Feeling dizzy or lightheaded

Less Common Side Effects

Constipation
Stomach pain
Toothache
Muscle spasms
Muscle pain

Naloxone serious side effects

Contact your healthcare provider immediately if you experience any of the following.

Sudden opioid withdrawal symptoms: aggressive behavior, pain, fast heartbeat, sweating, irritability, vomiting

Source: FDA

The following Naloxone side effects have also been reported

Side effects that you should report to your care team as soon as possible:

Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat

Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):

Agitation, feeling irritable or restless
Confusion
Dizziness
Nausea

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Pros and cons of Naloxone

Pros

Can help save the life of someone who has overdosed on opioids
Can be used in both adults and children
Works quickly to reverse the effects of opioids
Comes as an easy-to-use nasal spray and auto-injector
Available without a prescription from provider

Cons

Has to be given right away and doesn't take the place of emergency medical care
Might need to give multiple doses
Can cause opioid withdrawal symptoms, such as body aches, anxiety, sweating, and vomiting
Effects start to wear off in 30 to 90 minutes

Pharmacist tips for Naloxone

During an opioid overdose, the person who needs help often can't give themselves naloxone because they're not awake or can't breathe. It's important for family and friends to recognize the signs and symptoms of an opioid overdose (unusual sleepiness, trouble breathing, small pupils, slow pulse) so they can help their loved one in need. Family and friends should also be familiar with how to give naloxone in an emergency.
Call 911 or get emergency medical help right away when you think someone is experiencing symptoms of an opioid overdose. Make sure to do this before giving naloxone. This is because this person will likely need more medical attention. Continue to monitor the person's symptoms and repeat doses of naloxone as needed until emergency medical help arrives.
Make sure to give naloxone as soon as you notice any signs or symptoms of an opioid overdose in someone, such as extreme sleepiness, trouble breathing, small pupils, and cold or clammy skin. Getting naloxone right away can help lower the risk for serious harm or death.
Check the expiration date of naloxone regularly to make sure that it's still good to use. An expired naloxone might not work as well when given in an emergency situation, which can be life-threatening.
Store naloxone at room temperature before using. Keep the medication in its original container to protect it from light or changes in temperature.

Tips for using naloxone injection (Zimhi)

Because Zimhi is an injection, it might be difficult for certain people to push the plunger. According to the manufacturer, only people who are 12 years and older should inject Zimhi into someone who's experiencing an opioid overdose. A child who's younger than 12 years old might not have the hand strength to inject this medication.
Take off the cap from the needle. Press the needle into the person's outer thigh and push down on the plunger until you hear a click sound. If necessary, you can inject through clothing.
After 2 seconds, pull the safety guard down over the needle. Keep your fingers behind the needle to avoid injury.
Discard used Zimhi in a blue case provided with the medication.
If the solution inside the Zimhi device is yellow or brown color, cloudy, or contains particles, throw away the medication and get a new one.

Tips for using naloxone nasal spray (Kloxxado, Narcan, and generic naloxone)

Each nasal spray contains only 1 dose of medication and can't be reused. Don't test or prime the nasal spray before giving it. This will waste all or part of the medication.
To use the nasal spray, lay the person on their back and gently tilt their head back to receive a dose of naloxone. Afterwards, turn the person so that they're laying on their side.
If the person doesn't wake up, respond to voice or touch, or breathe normally within 2-3 minutes of receiving naloxone, you can give another dose of naloxone. Use a new naloxone nasal spray and alternate (switch) nostrils with each dose.

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Common questions about Naloxone

Call 911 for medical help right away if you notice someone is experiencing symptoms of an opioid overdose, such as extreme sleepiness, trouble breathing, and the body going limp. You should give Naloxone as soon as possible, after you've called for help. If you're not sure whether or not it's an opioid overdose, just treat it like one and give the Naloxone. If it ends up not being an opioid overdose, receiving Naloxone won't harm a person. But if it is an opioid overdose, getting Naloxone in a timely manner can save that person's life.

There is no limit or recommended maximum dose for Naloxone. Some people, especially those who've taken a very potent opioid, might need more than one dose of Naloxone to reverse the overdose. You're recommended to give Naloxone every 2-3 minutes until that person responds to the medication (starts to wake up or breathe normally on their own). Once the person responds, please stay by their side to monitor them until emergency medical help arrives.

Naloxone can start to work in as quickly as 2 to 3 minutes to restore someone's breathing. Its effects typically last 30 to 90 minutes. One thing to keep in mind is that the effects of certain opioids last much longer than that of Naloxone. This means that Naloxone can wear-off long before the opioid does, which can put a person at risk for opioid dose again. It's important to call for medical help so that the person can get monitored by a healthcare professional.

Yes, Naloxone can be administered to children as young as newborns. However, the way that this medication is absorbed in children's bodies can be unpredictable. Therefore, children should be monitored carefully for at least 24 hours after administration to make sure that the medication is working properly. Call 911 right away if you think a child might be experiencing an opioid overdose.

Kloxxado and Narcan are both Naloxone nasal sprays that can be used for someone who has overdosed on opioids. The main difference between them is that each spray of Kloxxado contains 8 mg of naloxone and each spray of Narcan contains 4 mg of naloxone. Kloxxado contains a higher dose of Naloxone because some data have shown that 34% of opioid overdose cases require at least 2 doses of Narcan nasal spray in order to resolve symptoms of overdose. Since Kloxxado contains a higher dose of Naloxone, it might lessen the need to give additional doses. Talk with your provider to see which Naloxone nasal spray is a better option.

Risks and warnings for Naloxone

Naloxone can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.

Opioid withdrawal

Risk factors: Regular use of opioids | Infants (under a month old) who have received opioids | Use of opioids during surgery

Naloxone can cause a sudden opioid withdrawal or unmask pain in those who regularly take opioids or have received opioids during a surgery. Symptoms can include pain, belly pain, diarrhea, fast heartbeat, fever, sweating, nausea, vomiting, irritability, and trembling. In infants with sudden opioid withdrawal, symptoms can be life-threatening and may include seizures, cry more than normal, and irregular reflexes. Let the provider know immediately and monitor these symptoms carefully in someone who has just received naloxone.

Worsening symptoms of opioid overdose

Risk factors: Taking long-acting opioids

Sometimes, a person can experience worsening symptoms of opioid overdose, even though their condition initially improved with naloxone. This is because the effects of naloxone wear off in about 30 to 90 minutes. But most opioids will stay in the body for much longer than that. That's why it's important to always call for emergency help when someone has an opioid overdose. Make sure to stay with that person after giving them naloxone, even if they look like their symptoms are improving, until medical help arrives.

Limited effectiveness

Risk factors: Taking pain medications that contain buprenorphine or pentazocine

If someone is taking opioids that have mixed activities (blocking and stimulating at opioid receptors), like buprenorphine, the naloxone might not work as well. They might multiple doses of naloxone to reverse the effect of this type of medication. Make sure to always use a new naloxone device or nasal spray for repeated doses.

Heart problems

Risk factors: History of heart problems | Taking medications that affect the heart | Use of opioids during surgery

If you have a history of heart problems or are taking medications that can cause heart problems, talk to your provider before going into any surgery that requires you to use opioids. This is because naloxone is commonly used after surgeries to reverse the effect of opioids. But naloxone can cause serious heart problems, such as seizures, irregular heartbeat, fluid buildup in lungs, or changes blood pressure. In rare cases, it can cause brain problems, coma, and even death. If you have a scheduled surgery, let your provider know about your medical history before the procedure.

Naloxone dosage

The average cost for 1 box of two 4mg nasal sprays of Naloxone is $31.09 with a free GoodRx coupon. This is 74.31% off the average retail price of $121.01.

Box

Dosage	Quantity	Price as low as	Price per unit
two 4mg nasal sprays	1 box	$31.09	$31.09

Syringe

Dosage	Quantity	Price as low as	Price per unit
1ml of 0.4mg/ml	1 syringe	$11.07	$11.07
2ml of 2mg/2ml	1 syringe	$15.96	$15.96

Vial

Dosage	Quantity	Price as low as	Price per unit
1ml of 0.4mg/ml	1 vial	$9.33	$9.33
10ml of 0.4mg/ml	1 vial	$26.00	$26.00

Typical dosage for Naloxone

Naloxone nasal sprays (generic, Narcan, Kloxxado)

Each spray of Narcan (and its generic) contains 4 mg of naloxone. Each spray of Kloxxado contains 8 mg of naloxone.

Opioid overdose: Call 911 first, then give naloxone. The typical dose is 1 spray of naloxone in one nostril as a single dose. If the person doesn't respond after 2 to 3 minutes, spray a second dose in the other nostril using a new nasal spray. Continue to repeat the dose with a new nasal spray every 2 to 3 minutes if the person doesn't respond, until medical help arrives.

Naloxone auto-injector (Zimhi)

Opioid overdose: Call 911 first, then give naloxone. The typical dose is to inject 5 mg of naloxone into the muscle of outer thigh (or under the skin) as one single dose. You can repeat a dose every 2 to 3 minutes if the person doesn't respond, until medical help arrives.

Naloxone intravenous (IV) injection is given by a healthcare provider to raise blood pressure in septic shock and to reverse the effects of opioids used during surgery.