6 Narcan Side Effects You Should Know About

Narcan (naloxone) is a medication that can reverse the effects of an opioid overdose. That's why it's sometimes referred to as the "opioid antidote."

Narcan comes as a nasal spray and an injection. Narcan nasal spray is available over the counter (OTC). The injection is prescription-only. And both forms of Narcan may be available at no cost through city and state programs across the U.S. Either one can be life-saving for someone experiencing an opioid overdose.

While Narcan usually doesn't cause side effects, they are possible. Narcan side effects aren't as dangerous as the life-threatening effects of an opioid overdose. Still, it's a good idea to know what to expect if you receive Narcan.

Narcan side effects at a glance

Most Narcan nasal spray and injectable side effects are mild. And most side effects aren't from Narcan itself. Instead, they're usually related to opioid withdrawal, which can occur as Narcan starts working.

Common, typically mild Narcan side effects include:

• Opioid withdrawal symptoms, such as nausea, vomiting, and headaches

• Nasal symptoms like burning, dryness, and sneezing (with the nasal spray)

• Injection site reactions (with the injection)

• Muscle pain

• Increased blood pressure

Rare but serious Narcan side effects include:

• Heart problems

• Severe agitation

Below, we'll go into more detail about six Narcan side effects.

1. Opioid withdrawal

Opioid withdrawal refers to symptoms that can occur when opioids are suddenly stopped after long-term use or when an opioid dosage is reduced too quickly. Additionally, opioid withdrawal can happen after receiving Narcan. This is because Narcan rapidly blocks the effects of opioids.

When you're used to having opioids in your system, your body can experience a range of uncomfortable symptoms when their effects are eliminated. Symptoms of opioid withdrawal include physical symptoms such as:

• Nausea and vomiting

• Runny nose

• Increased yawning

• Goosebumps

• Muscle, joint, and bone aches

• Sweating

• Heart palpitations

• High blood pressure

• Tremors

• Tearing up more than usual

Mood-related symptoms, such as anxiousness and irritability, can also occur. Although withdrawal symptoms are uncomfortable, they're not usually life-threatening. In almost all cases, opioid withdrawal symptoms are less dangerous than the effects of an opioid overdose.

It's a good idea to carry Narcan with you at all times if you or a loved one takes opioid medication. If you administer Narcan to someone, the person will still need medical treatment. Narcan effects don't last long, so call 911 after administering the medication.

When medical personnel arrive, they'll likely bring the person to the hospital for further treatment, including management of withdrawal symptoms. They may also recommend a medication for opioid use disorder, such as Suboxone (buprenorphine / naloxone) or methadone (Methadose).

If you or someone you know struggles with substance use, help is available. Call SAMHSA's National Helpline at 1-800-662-4357 to learn about resources in your area.

2. Muscle pain

Narcan may cause muscle pain. But it can be hard to tell whether Narcan itself is causing muscle pain or whether it's a symptom of opioid withdrawal.

Like opioid withdrawal itself, muscle pain related to opioid withdrawal can last days to weeks. However, if you're diagnosed with an opioid use disorder, medications like Suboxone and methadone can help minimize withdrawal symptoms.

Additionally, you can try some home remedies to relieve muscle pain:

• Icing the muscles that hurt

• Rubbing essential oils such as arnica or bergamot onto the muscles

• Using topical, OTC pain-relieving creams such as Voltaren Arthritis Pain (diclofenac) gel, Aspercreme (lidocaine), or Biofreeze (menthol)

• Taking an oral OTC pain reliever, such as ibuprofen (Advil) or acetaminophen (Tylenol), that's been approved by a healthcare professional

If you have muscle pain that lasts longer than a few days, talk to a healthcare professional. This may be a sign that you're experiencing opioid withdrawal and you need treatment to help manage it.

3. Heart problems

When you receive Narcan, your blood pressure may increase as a symptom of opioid withdrawal. Narcan can also cause arrhythmias, which are abnormal, irregular heartbeats. This may be more likely if you were taking high dosages of opioids, or using illegal drugs, before receiving Narcan. Arrhythmias can be life-threatening and may require emergency medical treatment.

After receiving Narcan and follow-up medical care, make sure you talk with a healthcare professional about how to monitor for heart problems at home. They may advise you to check your blood pressure and heart rate daily, especially if you have a history of heart problems. However, if you experience severe heart-related side effects at any point - such as fainting, chest pain, or a severe headache - seek emergency medical care. This may indicate your blood pressure is too high or that you're having other heart problems.

4. Nausea and vomiting

Narcan may also cause nausea and vomiting. Though, like muscle pain and high blood pressure, these may be symptoms of opioid withdrawal versus true Narcan side effects.

While nausea and vomiting related to Narcan are usually mild, excessive or prolonged vomiting may lead to dehydration. So it's important to stay hydrated if you're experiencing vomiting, especially because dehydration can make nausea worse.

If you're feeling nauseous, here are a few things that can help:

• Eating smaller (but more frequent) meals throughout the day

• Sticking to bland foods like bananas, rice, and toast for a few days

• Taking an OTC medication such as Pepto-Bismol (bismuth subsalicylate) or Nauzene (sodium citrate dihydrate) - or a prescription medication like ondansetron (Zofran) - with the approval of a healthcare professional

If you have nausea and vomiting that lasts several days or becomes so severe that you're not able to keep food or water down, seek emergency medical care. You may need intravenous fluids or medications.

5. Headaches

Headaches are also a potential side effect of Narcan, as well as a symptom of opioid withdrawal. Staying hydrated,meditating, and getting enough sleep can help manage headaches. Taking OTC pain relievers such as acetaminophen or ibuprofen may also help.

If you have a headache that's extremely painful, escalates quickly, or is worse when lying down, seek emergency care. This could be a sign that something else is going on. For example, very high blood pressure, which may require immediate medical attention, can cause a severe headache.

6. Nasal symptoms

If you receive Narcan nasal spray, you may experience nasal congestion, pain in the nostrils, or sneezing. Nasal irritation should improve as Narcan wears off. So if you have a persistent dry nose, or you're experiencing a bloody nose or extreme irritation, talk with a healthcare professional about what to do next.