Naloxone Side Effects
Medically reviewed by Drugs.com. Last updated on Nov 12, 2020.
For the Consumer
Applies to naloxone: injection solution
Other dosage forms:
Side effects requiring immediate medical attention
Along with its needed effects, naloxone may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking naloxone:
Incidence not known
- Abdominal or stomach cramps
- body aches
- difficult or troubled breathing
- excessive crying
- fast, pounding, or irregular heartbeat or pulse
- increased or excessive unconscious or jerking movements
- irregular, fast or slow, or shallow breathing
- nausea or vomiting
- pale or blue lips, fingernails, or skin
- runny nose
For Healthcare Professionals
Applies to naloxone: compounding powder, injectable solution, nasal spray
This drug may precipitate abrupt opioid withdrawal in physically dependent persons; signs and symptoms may include body aches, fever, sweating, sneezing, yawning, nausea, vomiting, sweating, lacrimation, rhinorrhea, cramping, insomnia, chills/hot flashes, piloerection, tachycardia, anxiety, restlessness, irritability, tremulousness, hypertension, seizures, and cardiac arrest. In the neonate, opioid withdrawal may also include convulsions, excessive crying, and hyperactive reflexes.[Ref]
Common (1% to 10%): Tachycardia, hypotension, hypertension
Rare (less than 0.1%): Fibrillation, cardiac arrest
Frequency not reported: Left ventricular failure, flushing[Ref]
In postoperative patients, many of whom had cardiovascular disease, the following cardiovascular side effects have been reported: hypotension, hypertension, atrial and ventricular tachycardia, ventricular fibrillation, left ventricular failure, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events.[Ref]
Death, coma, and encephalopathy have been reported as a result of abrupt postoperative reversal of opioid depression, primarily in patients with preexisting cardiovascular disorders or in those who received other drugs with similar adverse cardiovascular effects.[Ref]
Common (1% to 10%): Dizziness, headache
Uncommon (0.1% to 1%): Tremor
Rare (less than 0.1%): Seizures
Frequency not reported: Coma, encephalopathy, convulsions, paraesthesia, grand mal convulsion[Ref]
Very rare (less than 0.01%): Pulmonary edema
It has been suggested that pulmonary edema may be due to a centrally mediated massive catecholamine response leading to a dramatic shift of blood volume into the pulmonary vascular bed resulting in increased hydrostatic pressures.
Nasal dryness, nasal edema, nasal congestion, and nasal inflammation were the most common adverse reactions reported in clinical trials with naloxone nasal spray.[Ref]
Frequency not reported: Nonspecific injection site reactions, irritation of vessel was after IV administration[Ref]
Common (1% to 10%): Nausea, vomiting
Uncommon (0.1% to 1%): Diarrhea, dry mouth[Ref]
Very rare (less than 0.01%): Erythema multiforme
Frequency not reported: Sweating[Ref]
Frequency not reported: Agitation, hallucination, tremulousness[Ref]
Musculoskeletal pain was one of the more commonly reported adverse reactions in clinical trials with naloxone nasal spray.[Ref]
Frequency not reported: Musculoskeletal pain[Ref]
1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
2. "Product Information. Narcan (naloxone)." DuPont Pharmaceuticals, Wilmington, DE.
3. Cerner Multum, Inc. "Australian Product Information." O 0
Frequently asked questions
- What's the difference between naltrexone and naloxone?
- What are the different types of buprenorphine/naloxone?
- How long does naloxone block opiates?
- How does naloxone work in an overdose?
- Does Sublocade have naloxone in it?
- How do you administer naloxone?
- Is this an addictive drug?
- Will naloxone keep drug users from seeking treatment?
- How do you administer Narcan Nasal Spray?
More about naloxone
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Interactions
- Compare Alternatives
- Support Group
- Pricing & Coupons
- 19 Reviews
- Drug class: antidotes
- FDA Alerts (2)
- Patient Information
- Naloxone Injection (Advanced Reading)
- Naloxone Nasal (Advanced Reading)
- Naloxone Auto-Injection
- Naloxone Injection
- Naloxone Nasal Spray
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.