Naloxone hydrochloride

What Naloxone hydrochloride is used for

Quoted from the “Indications and Usage” section of the FDA-approved label.

Naloxone Hydrochloride Injection is indicated for the complete or partial reversal of opioid depression, including respiratory depression, induced by natural and synthetic opioids including propoxyphene, methadone, and certain mixed agonist-antagonist analgesics: nalbuphine, pentazocine, butorphanol and cyclazocine. …

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Label quoted: the one for the most common form (injection, solution, intramuscular), Naloxone Hydrochloride, Hospira, Inc.; it covers 2 products in the FDA NDC Directory. The side effects, interactions, dosage and pregnancy quotes below come from this same label.

The FDA has 66 labels for products of this medicine (different makers and forms); uses can differ between them. Check the label that comes with your own medicine.

This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.

Boxed warning

A boxed warning (“black box”) is the FDA’s strongest warning on a drug label, for serious or life-threatening risks.

The label quoted above has no boxed warning.

0 of 66 FDA labels for this medicine have a boxed warning.

Naloxone hydrochloride side effects

Quoted from the “Adverse Reactions” section of the FDA-approved label. Tell your doctor about any side effect that worries you.

Postoperative The following adverse events have been associated with the use of naloxone hydrochloride injection in postoperative patients: hypotension, hypertension, ventricular tachycardia and fibrillation, dyspnea, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events.

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Excessive doses of naloxone in postoperative patients may result in significant reversal of analgesia and may cause agitation (see PRECAUTIONS and DOSAGE AND ADMINISTRATION; Usage in Adults-Postoperative Opioid Depression). Opioid Depression Abrupt reversal of opioid depression may result in nausea, vomiting, sweating, tachycardia, increased blood pressure, tremulousness, seizures, ventricular tachycardia and fibrillation, pulmonary edema, and cardiac arrest which may result in death (see PRECAUTIONS). Opioid Dependence Abrupt reversal of opioid effects in persons who are physically dependent on opioids may precipitate an acute withdrawal syndrome which may include, but not limited to the following signs and symptoms: body aches, fever, sweating, runny nose, sneezing, piloerection, yawning, weakness, shivering or trembling, nervousness, restlessness or irritability, diarrhea, nausea or vomiting, abdominal cramps, increased blood pressure, and tachycardia. In the neonate, opioid withdrawal may also include: convulsions, excessive crying, and hyperactive reflexes (see WARNINGS). Adverse events associated with the postoperative use of naloxone hydrochloride injection are listed by organ system and in decreasing order of frequency as follows: Cardiac Disorders: pulmonary edema, cardiac arrest or failure, tachycardia, ventricular fibrillation, and ventricular tachycardia. Death, coma, and encephalopathy have been reported as sequelae of these events. Gastrointestinal Disorders: vomiting, nausea Nervous System Disorders: convulsions, paraesthesia, grand mal convulsion Psychiatric Disorders: agitation, hallucination, tremulousness Respiratory, Thoracic, and Mediastinal Disorders: dyspnea, respiratory depression, hypoxia Skin and Subcutaneous Tissue Disorders: nonspecific injection site reactions, sweating Vascular Disorders: hypertension, hypotension, hot flashes, or flushing See also PRECAUTIONS and DOSAGE AND ADMINISTRATION; Usage in Adults, Postoperative Opioid Depression

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Naloxone hydrochloride drug interactions

Quoted from the “Drug Interactions” section of the FDA-approved label. Tell your pharmacist about every medicine, vitamin and herbal product you take.

Large doses of naloxone are required to antagonize buprenorphine since the latter has a long duration of action due to its slow rate of binding and subsequent slow dissociation from the opioid receptor. Buprenorphine antagonism is characterized by a gradual onset of the reversal effects and a decreased duration of action of the normally prolonged respiratory depression.

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The barbiturate methohexital appears to block the acute onset of withdrawal symptoms induced by naloxone in opiate addicts.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Naloxone hydrochloride dosage

Quoted from the “Dosage and Administration” section of the FDA-approved label. Your own dose is the one your doctor prescribes: do not change it on your own.

Naloxone Hydrochloride Injection, USP may be administered intravenously, intramuscularly, or subcutaneously. The most rapid onset of action is achieved by intravenous administration and it is recommended in emergency situations. Since the duration of action of some opioids may exceed that of naloxone, the patient should be kept under continued surveillance. Repeated doses of naloxone should be administered, as necessary.

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Intravenous Infusion: Naloxone Hydrochloride Injection, USP may be diluted for intravenous infusion in 0.9% sodium chloride injection or 5% dextrose injection. The addition of 2 mg of naloxone hydrochloride in 500 mL of either solution provides a concentration of 0.004 mg/mL. Mixtures should be used within 24 hours. After 24 hours, the remaining unused solution must be discarded. The rate of administration should be titrated in accordance with the patient's response. Naloxone Hydrochloride Injection, USP should not be mixed with preparations containing bisulfite, metabisulfite, long-chain or high molecular weight anions, or any solution having an alkaline pH. No drug or chemical agent should be added to Naloxone Hydrochloride Injection, USP unless its effect on the chemical and physical stability of the solution has first been established. General Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration whenever solution and container permit. Usage in Adults: Opioid Overdose—Known or Suspected: An initial dose of 0.4 mg to 2 mg of naloxone hydrochloride may be administered intravenously. If the desired degree of counteraction and improvement in respiratory functions is not obtained, it may be repeated at 2 to 3 minute intervals. If no response is observed after 10 mg of naloxone hydrochloride have been administered, the diagnosis of opioid induced or partial opioid induced toxicity should be questioned. Intramuscular or subcutaneous administration may be necessary if the intravenous route is not available. Postoperative Opioid Depression: For the partial reversal of opioid depression following the use of opioids during surgery, smaller doses of naloxone hydrochloride are usually sufficient. The dose of naloxone should be titrated according to the patient's response. For the initial reversal of respiratory depression, naloxone hydrochloride should be injected in increments of 0.1 to 0.2 mg intravenously at two to three minute intervals to the desired degree of reversal, i.e., adequate ventilation and alertness without significant pain or discomfort. Larger than necessary dosage of naloxone may result in significant reversal of analgesia and increase in blood pressure. Similarly, too rapid reversal may induce nausea, vomiting, sweating or circulatory stress. Repeat doses of naloxone may be required within one to two hour intervals depending upon the amount, type (i.e., short or long acting) and time interval since last administration of opioid. Supplemental intramuscular doses have been shown to produce a longer lasting effect.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. This is part of the section. Read the full label on DailyMed →

Naloxone hydrochloride in pregnancy

Quoted from the pregnancy part of the FDA-approved label. Ask your doctor before you take any medicine while pregnant or planning a pregnancy.

Teratogenic Effects: Teratology studies conducted in mice and rats at doses 4-times and 8-times, respectively, the dose of a 50 kg human given 10 mg/day (when based on surface area or mg/m 2), demonstrated no embryotoxic or teratogenic effects due to naloxone. There are, however, no adequate and well controlled studies in pregnant women.

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Because animal reproduction studies are not always predictive of human response, naloxone hydrochloride should be used during pregnancy only if clearly needed. Non-teratogenic Effects: Risk-benefit must be considered before naloxone is administered to a pregnant woman who is known or suspected to be opioid-dependent since maternal dependence may often be accompanied by fetal dependence. Naloxone crosses the placenta, and may precipitate withdrawal in the fetus as well as in the mother. Patients with mild to moderate hypertension who receive naloxone during labor should be carefully monitored as severe hypertension may occur.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Naloxone hydrochloride and breastfeeding

Quoted from the nursing mothers / lactation part of the FDA-approved label.

It is not known whether naloxone is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when naloxone hydrochloride is administered to a nursing woman.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

When Naloxone hydrochloride should not be used

Quoted from the “Contraindications” section of the FDA-approved label.

Naloxone hydrochloride injection is contraindicated in patients known to be hypersensitive to naloxone hydrochloride or to any of the other ingredients contained in the formulation.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Naloxone hydrochloride overdose

Quoted from the “Overdosage” section of the FDA-approved label. If someone may have taken too much, call Poison Help at 1-800-222-1222 (or 911 in an emergency).

There is limited clinical experience with naloxone hydrochloride injection overdosage in humans. Adult Patients In one small study, volunteers who received 24 mg/70 kg did not demonstrate toxicity. In another study, 36 patients with acute stroke received a loading dose of 4 mg/kg (10 mg/m 2 /min) of naloxone hydrochloride injection followed immediately by 2 mg/kg/hr for 24 hours.

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Twenty-three patients experienced adverse events associated with naloxone use, and naloxone was discontinued in seven patients because of adverse effects. The most serious adverse events were: seizures (2 patients), severe hypertension (1), and hypotension and/or bradycardia (3). At doses of 2 mg/kg in normal subjects, cognitive impairment and behavioral symptoms, including irritability, anxiety, tension, suspiciousness, sadness, difficulty concentrating, and lack of appetite have been reported. In addition, somatic symptoms, including dizziness, heaviness, sweating, nausea, and stomachaches were also reported. Although complete information is not available, behavioral symptoms were reported to often persist for 2 to 3 days. Pediatric Patients Up to 11 doses of 0.2 mg naloxone (2.2 mg) have been administered to children following overdose of diphenoxylate hydrochloride with atropine sulfate. Pediatric reports include a 2½ year-old child who inadvertently received a dose of 20 mg naloxone for treatment of respiratory depression following overdose with diphenoxylate hydrochloride with atropine sulfate. The child responded well and recovered without adverse sequelae. There is also a report of a 4½ year-old child who received 11 doses during a 12-hour period, with no adverse sequelae. Patient Management Patients who experience a naloxone overdose should be treated symptomatically in a closely supervised environment. Physicians should contact a poison control center for the most up-to-date patient management information.

— FDA label: Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026. Read the full label on DailyMed →

Forms and how it is given

Same medicine, other forms and combinations

Prescription medicine pages on this site that share an active ingredient with this one, from the FDA NDC Directory. A combination is a different medicine: ask your pharmacist before you switch.

Other medicines that contain Naloxone hydrochloride

• Buprenorphine and naloxoneZubsolv, Buprenorphine and Naloxone Sublingual Film · 102 products
• Pentazocine hydrochloride and naloxone hydrochloride3 products

Companies that list this medicine

Labelers in the FDA NDC Directory: the company named on the package (maker or distributor), with the number of prescription products.

• HF Acquisition Co LLC, DBA HealthFirst12 products
• Medical Purchasing Solutions, LLC9 products
• A-S Medication Solutions5 products
• Hikma Pharmaceuticals USA Inc.4 products
• International Medication Systems, Limited3 products
• Eugia US LLC3 products
• Baxter Healthcare Corporation3 products
• Hospira, Inc.3 products
• Mylan Institutional LLC3 products
• Henry Schein, Inc.3 products
• Somerset Therapeutics, LLC2 products
• Lifestar Pharma LLC2 products
• Fresenius Kabi USA, LLC2 products
• Proficient Rx LP2 products
• ProPharma Distribution2 products
• International Medication Systems, Ltd.1 product
• NorthStar RxLLC1 product
• Remedyrepack Inc.1 product
• ZMI Pharma Inc.1 product
• kaleo, Inc1 product
• Scienture LLC1 product
• BPI Labs LLC1 product
• Par Health USA, LLC1 product
• HF Acquisition Co. LLC, DBA Health First1 product
• Dr. Reddy's Laboratories Inc.1 product
• Sina Health Inc1 product
• Emergent Devices Inc.1 product
• Hikma Specialty USA Inc.1 product
• Civica, Inc.1 product

FDA approval history

• NDA: New Drug Application: how a new (usually brand-name) medicine is approved.
• ANDA: Abbreviated New Drug Application: how a generic version is approved.

Generic approvals (22)

• ANDA070299Hikma · October 22, 1985
• ANDA070172Hospira · April 18, 1986
• ANDA070256Hospira · January 7, 1987
• ANDA070257Hospira · January 7, 1987
• ANDA072076Intl Medication · March 24, 1988
• ANDA204997Mylan Institutional · March 6, 2014
• ANDA205014Mylan Institutional · June 29, 2016
• ANDA207634Somerset Theraps LLC · July 26, 2017
• ANDA207633Somerset Theraps LLC · August 8, 2017
• ANDA212455Eugia Pharma · October 15, 2019
• ANDA212456Eugia Pharma · November 4, 2019
• ANDA213209DR Reddys · March 16, 2020
• ANDA213279Eugia Pharma · January 14, 2021
• ANDA214785Baxter Hlthcare Corp · January 29, 2021
• ANDA213843Mylan Labs Ltd · June 9, 2022
• ANDA212300Hikma · June 10, 2022
• ANDA211951Padagis Israel · June 21, 2022
• ANDA215964Ph Health · July 29, 2022
• ANDA214792Baxter Hlthcare Corp · November 7, 2022
• ANDA216977Bpi Labs · October 6, 2023
• ANDA218404Mankind Pharma · February 29, 2024
• ANDA213573Fresenius Kabi USA · April 2, 2024

Shortage status

The FDA drug shortage list does not show these products.

FDA Drug Shortages database →

Recalls

From FDA enforcement reports, matched by the product’s NDC code. A recall usually covers specific lots only: check the lot number on your package and ask your pharmacist. Do not stop a medicine on your own.

1. March 15, 2021 · Class II · Terminated · D-0473-2021

   CGMP Deviations: Intermittent exposure to temperature excursion during storage.

   Narcan (naloxone HCl) Nasal Spray 4 mg Two Pack This box contains two (2) 4-mg doses of naloxone HCl in 0.1 mL of nasal spray. 0.1 mL intranasal spray per unit For use in the nose only Rx only NDC 69547-353-02 Distribute — Cardinal Health Inc.

2. June 4, 2018 · Class I · Terminated · D-0906-2018

   Presence of Particulate Matter; Potential for particulate matter on the syringe plunger.

   Naloxone Hydrochloride Injection, USP, 0.4 mg/mL, 1 mL in 2.5 mL Carpuject Single-use cartridge syringe, Single unit (NDC 0409-1782-03) and 10 count box (NDC 0409-1782-69), Rx Only, Hospira Inc., Lake Forest, IL — HOSPIRA INC, LAKE FOREST

Official identifiers

Next steps

• Find a pharmacy near youAsk which price applies to you and whether your product is affected by a recall
• Latest FDA drug recallsAll medicines, newest first
• Naloxone sold over the counterDrug Facts label and store brands
• NarcanBrand page: products, maker and price
• KloxxadoBrand page: products, maker and price
• Naloxone HciBrand page: products, maker and price
• Narcan Naloxone HciBrand page: products, maker and price
• HF Acquisition Co LLC, DBA HealthFirstMaker or distributor
• Medical Purchasing Solutions, LLCMaker or distributor
• A-S Medication SolutionsMaker or distributor
• All prescription drugs A to ZSearch by generic, brand or Spanish name

Sources

1. FDA-approved label on DailyMed (National Library of Medicine) — Naloxone Hydrochloride, Hospira, Inc., effective May 27, 2026; via openFDA, FDA data exported October 30, 2026, retrieved October 31, 2026
2. NDC Directory (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
3. Drugs@FDA (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
4. Drug recall enforcement reports (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 27, 2026, retrieved October 31, 2026
5. Drug shortages (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026

openFDA data is provided by the FDA as is; it may be incomplete. Always rely on the label that comes with your medicine. FDA Enforcement Report search →

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