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NALOXONE HCl 4 mg/.1mL Spray, 1 mL — NDC 51662-1620-01 package photo
Label image from the product's FDA listing (DailyMed) — may show a different pack size or an older label revision.

NALOXONE HCl 4 mg/.1mL Spray, 1 mL — NDC 51662-1620-1 (Billing 51662-1620-01)

by HF Acquisition Co LLC, DBA HealthFirst · .1 mL in 1 VIAL, SINGLE-DOSE

This is a package of 1 mL of NALOXONE HCl 4 mg/.1mL Spray from HF Acquisition Co LLC, DBA HealthFirst, marketed since Apr 2023 and currently FDA-listed. It is the main listing for this product, which comes in 2 package sizes.

NDC 51662-1620-01
🏷️ FDA NDC (as labeled) 51662-1620-1 billing pads the package segment with a zero
This package
Contains1 mL Pack sizes2 compare ↓
Main listing for product 51662-1620 · Also comes in: 2 vials 51662-1620-2
Rx only Generic On market Non-controlled ⇄ Compare with another NDC
🗂️ FDA directory synced Oct 1, 2026 · this listing last changed Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

Identity & classification

Regulatory identifiers FDA, NLM and CMS codes for this package

FDA NDC (as labeled) 51662-1620-1
Product NDC 51662-1620
11-digit billing NDC 51662162001
RxCUI 1725059
UNII F850569PQR
UPC 0345802811004
Application # ANDA211951
SPL Set ID f8fcda15-8ba6-e66a-e053-6294a90a385c
Established class (EPC) Opioid Antagonist
Mechanism of action Opioid Antagonists
DEA schedule Non-controlled
Marketing category ANDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 2023-04-10
Route NASAL
Dosage form SPRAY
Substance NALOXONE HYDROCHLORIDE
Quick answers
  • RxCUI (RxNorm): 1725059
Why two NDCs? The FDA registers this code as 51662-1620-1 — a 5-4-1 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the package segment → 51662-1620-01. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

RxNorm drug class

This medicine belongs to the Opioid Antagonist class.

Pharmacologic class Opioid Antagonist
Drug family (ATC) Other opioids, Natural opium alkaloids, Benzomorphan derivatives
How it works Opioid Antagonists
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

Clinical

📖 What it is MedlinePlus · NLM

Naloxone nasal spray is used along with emergency medical treatment to reverse the life-threatening effects of a known or suspected opiate (narcotic) overdose. Naloxone nasal spray is in a class of medications called opiate antagonists. It works by blocking the effects of opiates to relieve dangerous symptoms caused by high levels of opiates in the blood.

Read the full MedlinePlus article ↗
📗 Our plain-language guide HelloPharmacist
  • It is an emergency medicine that reverses an opioid overdose. Signs include very slow or stopped breathing and being unresponsive. Some injection forms have extra hospital or milit...
  • Follow the instructions that came with your product. Nasal sprays go into one nostril. Zimhi goes into the outer thigh. Call 911 right away. If the person does not wake up or slips...
  • Naloxone can wear off before the opioid does. Breathing problems can come back. Stay with the person until emergency help arrives.
  • Why do I still need to call 911 if they wake up?
📖 Read our full Naloxone guide →
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer mLPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Try another pack size: 2 vials
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

Packaging — all sizes for this product

Package NDCDescription Marketing startMarketing endStatus
51662-1620-01 You're viewing this Main listing .1 mL in 1 VIAL, SINGLE-DOSE 2023-04-10 — Active
51662-1620-02 51662-1620-2 2 VIAL, SINGLE-DOSE in 1 CARTON / .1 mL in 1 VIAL, SINGLE-DOSE 2023-04-10 — Active

Pack size FAQ

What quantity is in this package?
This package contains 1 mL — .1 ml in 1 vial, single-dose.
How does this package differ from NDC 51662-1620-02?
Both are NALOXONE HCl 4 mg/.1mL Spray — the drug itself is identical. This page's package is the 1 mL one, while NDC 51662-1620-02 is the 2 vials package.
What NDC number is used to bill for this package of NALOXONE HCl 4 mg/.1mL Spray?
Use the 11-digit billing form listed in the identifiers section of this page. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Narcan 4 mg/.1mL 69547-0627-02 Emergent 2 vials $16.449 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 00480-3478-68 Teva 1 vial $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 45802-0578-84 Padagis 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 46122-0812-71 AMERISOURCE 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 60219-2104-07 Amneal 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 68001-0645-45 BluePoint 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 69238-2104-07 Amneal 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 70677-1283-01 Strategic 2 vials $17.177 — Availability likely —
Naloxone Hydrochloride 4 mg/.1mL 00093-2165-68 Teva 1 vial $34.270 — Discontinued —
Naloxone Hydrochloride 4 mg/.1mL 00363-2140-02 Walgreen 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 00591-3871-99 Actavis 1 vial — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 42291-0493-02 AvKARE 2 vials — — FDA listed —
Narcan 4 mg/.1mL 50090-2422-00 A-S 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 50090-5908-00 A-S 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 50090-6710-00 A-S 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 50090-6963-00 A-S 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 51316-0210-02 CVS 2 vials — — FDA listed —
Narcan Naloxone Hci 4 mg/.1mL 51662-1240-01 HF 1 ml — — FDA listed —
NALOXONE HCl 4 mg/.1mLthis 51662-1620-01 HF 1 ml — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 51662-1659-02 HF 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 67296-1928-02 Redpharm 1 vial — — Discontinued —
Narcan 4 mg/.1mL 71205-0528-02 Proficient 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 71205-0707-02 Proficient 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 72162-2376-02 Bryant 2 vials — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 76420-0867-02 Asclemed 1 vial — — FDA listed —
Naloxone Hydrochloride 4 mg/.1mL 80425-0409-01 Advanced 2 vials — — FDA listed —
Narcan 4 mg/.1mL 85766-0076-02 Sportpharm 2 vials — — FDA listed —
About this product: this is a generic version of the medicine. FDA equivalence ratings are shown when available, and other versions are listed above, least expensive first.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
2023
On the market since
Apr 2023
📍
2026
Currently FDA-listed
3 years listed
🔓
·
Generic on the market
this product is a generic
✅This is a generic drug

This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

A current SPL was checked, but it does not contain a structured or narrative inactive-ingredient list for this product. This does not mean the product has no inactive ingredients.
Where does this data come from?
Source: official FDA Structured Product Labeling (SPL) via DailyMed and the openFDA label index. Structured IACT rows and label-wide narrative are kept separate; availability and product-level specificity depend on the submitted label.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

Manufacturer & labeler

LabelerHF Acquisition Co LLC, DBA HealthFirst
Application holderPADAGIS ISRAEL PHARMACEUTICALS LTD
FDA applicationANDA211951 (ANDA)
Labeler code51662
First marketedApr 2023
Product typeHuman Prescription Drug
Portfolio333 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Very long sections are excerpted here and marked; the full text is on DailyMed (linked in the sources below). Jump with a chip, search within the label, or expand everything.
🎯 Indications and Usage 101 words ▾

1 INDICATIONS & USAGE Naloxone HCl Nasal Spray is indicated for the emergency treatment of known or suspected opioid overdose, as manifested by respiratory and/or central nervous system depression. Naloxone HCl Nasal Spray is intended for immediate administration as emergency therapy in settings where opioids may be present. Naloxone HCl Nasal Spray is not a substitute for emergency medical care.

Limitations of Use: Restrict prescription of naloxone hydrochloride nasal spray 2 mg to opioid-dependent patients expected to be at risk for severe opioid withdrawal in situations where there is a low risk for accidental or intentional opioid exposure by household contacts.

⏱️ Dosage and Administration ~3 min read ▾

2 DOSAGE & ADMINISTRATION

2.1Important Administration Instructions Naloxone HCl Nasal Spray is for intranasal use only. No additional device assembly is required. Because treatment of suspected opioid overdose must be performed by someone other than the patient, instruct the prescription recipient to inform those around them about the presence of Naloxone HCl Nasal Spray and the Instructions for Use.

Instruct the patient or caregiver to read the Instructions for Use at the time they receive a prescription for Naloxone HCl Nasal Spray. Emphasize the following instructions to the patient or caregiver: • Administer Naloxone HCl Nasal Spray as quickly as possible because prolonged respiratory depression may result in damage to the central nervous system or death. Since the duration of action of most opioids exceeds that of naloxone hydrochloride and the suspected opioid overdose may occur outside of supervised medical settings, seek immediate emergency medical assistance, keep the patient under continued surveillance until emergency personnel arrive, and administer repeated doses of Naloxone HCl Nasal Spray, as necessary.

Always seek emergency medical assistance in the event of a suspected, potentially life-threatening opioid emergency after administration of the first dose of Naloxone HCl Nasal Spray. • Additional doses of Naloxone HCl Nasal Spray may be required until emergency medical assistance becomes available. • Do not attempt to reuse Naloxone HCl Nasal Spray. Each Naloxone HCl Nasal Spray contains a single dose of naloxone and cannot be reused. • Re-administer Naloxone HCl Nasal Spray, using a new nasal spray, every 2 to 3 minutes if the patient does not respond or responds and then relapses into respiratory depression. • Administer Naloxone HCl Nasal Spray in alternate nostrils with each dose. • Administer Naloxone HCl Nasal Spray according to the printed instructions on the device label and the Instructions for Use. • Place the patient in the supine position.

Prior to administration, be sure the device nozzle is inserted in either nostril of the patient, and provide support to the back of the neck to allow the head to tilt back. Do not prime or test the device prior to administration. • To administer the dose, press firmly on the device plunger. • Remove the device nozzle from the nostril after use. • Turn patient on their side as shown in the Instructions for Use and call for emergency medical assistance immediately after administration of the first dose of Naloxone HCl Nasal Spray.

2.2Dosing in Adults and Pediatric Patients Initial Dosing The recommended initial dose of Naloxone HCl Nasal Spray in adults and pediatric patients is one spray delivered by intranasal administration into one nostril. Repeat Dosing Seek emergency medical assistance as soon as possible after administering the first dose of Naloxone HCl Nasal Spray. The requirement for repeat doses of Naloxone HCl Nasal Spray depends upon the amount, type, and route of administration of the opioid being antagonized.

Administer Naloxone HCl Nasal Spray in alternate nostrils with each dose. If the patient responds to Naloxone HCl Nasal Spray and relapses back into respiratory depression before emergency assistance arrives, administer an additional dose of Naloxone HCl Nasal Spray using a new Naloxone HCl Nasal Spray and continue surveillance of the patient. If the desired response is not obtained after 2 or 3 minutes, administer an additional dose of Naloxone HCl Nasal Spray using a new Naloxone HCl Nasal Spray.

If there is still no response and additional doses are available, administer additional doses of Naloxone HCl Nasal Spray every 2 to 3 minutes using a new Naloxone HCl Nasal Spray with each dose until emergency medical assistance arrives. Additional supportive and/or resuscitative measures may be helpful while awaiting emergency medical assistance.

2.3Dosing Modifications due to Partial Agonists or Mixed Agonist/Antagonists Reversal of respiratory de… [Excerpted — this section continues on DailyMed.]

💊 Dosage Forms and Strengths 25 words ▾

3 DOSAGE FORMS & STRENGTHS Naloxone HCl Nasal Spray is supplied as a single-dose intranasal spray containing 4 mg of naloxone hydrochloride in 0.1 mL.

⛔ Contraindications 24 words ▾

4 CONTRAINDICATIONS Naloxone HCl Nasal Spray is contraindicated in patients known to be hypersensitive to naloxone hydrochloride or to any of the other ingredients.

⚠️ Warnings and Cautions ~3 min read ▾

5 WARNINGS AND PRECAUTIONS

5.1Risk of Recurrent Respiratory and Central Nervous System Depression The duration of action of most opioids may exceed that of Naloxone HCl Nasal Spray resulting in a return of respiratory and/or central nervous system depression after an initial improvement in symptoms. Therefore, it is necessary to seek emergency medical assistance immediately after administration of the first dose of Naloxone HCl Nasal Spray and to keep the patient under continued surveillance. Administer additional doses of Naloxone HCl Nasal Spray if the patient is not adequately responding or responds and then relapses back into respiratory depression, as necessary [see Dosage and Administration ( 2.2 )].

Additional supportive and/or resuscitative measures may be helpful while awaiting emergency medical assistance.

5.2Risk of Limited Efficacy with Partial Agonists or Mixed Agonist/Antagonists Reversal of respiratory depression by partial agonists or mixed agonist/antagonists such as buprenorphine and pentazocine, may be incomplete. Larger or repeat doses of naloxone hydrochloride may be required to antagonize buprenorphine because the latter has a long duration of action due to its slow rate of binding and subsequent slow dissociation from the opioid receptor [see Dosage and Administration (2.3 )]. Buprenorphine antagonism is characterized by a gradual onset of the reversal effects and a decreased duration of action of the normally prolonged respiratory depression.

5.3Precipitation of Severe Opioid Withdrawal The use of Naloxone HCl Nasal Spray in patients who are opioid-dependent may precipitate opioid withdrawal characterized by the following signs and symptoms: body aches, diarrhea, tachycardia, fever, runny nose, sneezing, piloerection, sweating, yawning, nausea or vomiting, nervousness, restlessness or irritability, shivering or trembling, abdominal cramps, weakness, and increased blood pressure. In neonates, opioid withdrawal may be life-threatening if not recognized and properly treated and may include the following signs and symptoms: convulsions, excessive crying, and hyperactive reflexes.

Monitor the patient for the development of the signs and symptoms of opioid withdrawal. There are limited data to inform if the 2 mg dose of naloxone hydrochloride nasal spray will avoid precipitation of severe opioid withdrawal in the setting of opioid dependence. However, the 2 mg dose may not provide an adequate and timely reversal in persons who may be exposed to an overdose of a potent or very high dose of opioids.

Abrupt postoperative reversal of opioid depression after using naloxone hydrochloride may result in nausea, vomiting, sweating, tremulousness, tachycardia, hypotension, hypertension, seizures, ventricular tachycardia and fibrillation, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events. These events have primarily occurred in patients who had pre-existing cardiovascular disorders or received other drugs that may have similar adverse cardiovascular effects.

Although a direct cause and effect relationship has not been established, after use of naloxone hydrochloride, monitor patients with pre-existing cardiac disease or patients who have received medications with potential adverse cardiovascular effects for hypotension, ventricular tachycardia or fibrillation, and pulmonary edema in an appropriate healthcare setting. It has been suggested that the pathogenesis of pulmonary edema associated with the use of naloxone hydrochloride is similar to neurogenic pulmonary edema, i.e., a centrally mediated massive catecholamine response leading to a dramatic shift of blood volume into the pulmonary vascular bed resulting in increased hydrostatic pressures.

There may be clinical settings, particularly the postpartum period in neonates with known or suspected exposure to maternal opioid use, where it is preferable to avoid the abrupt precipitation of opioid withdra… [Excerpted — this section continues on DailyMed.]

🤒 Adverse Reactions ~1 min read ▾

6 ADVERSE REACTIONS The following serious adverse reactions are discussed elsewhere in the labeling: • Precipitation of Severe Opioid Withdrawal [see Warnings and Precautions ( 5.3) ] Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to the rates in the clinical studies of another drug and may not reflect the rates observed in practice. The following adverse reactions were observed in a naloxone hydrochloride nasal spray clinical study.

In a pharmacokinetic study of 30 healthy adult volunteers exposed to one spray of naloxone hydrochloride nasal spray in one nostril or two sprays of naloxone hydrochloride nasal spray, one in each nostril, the most common adverse reactions were: increased blood pressure, constipation, toothache, muscle spasms, musculoskeletal pain, headache, nasal dryness, nasal edema, nasal congestion, nasal inflammation, rhinalgia, and xeroderma. The following adverse reactions have been identified primarily during post-approval use of naloxone hydrochloride in the post-operative setting.

Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure: Hypotension, hypertension, ventricular tachycardia and fibrillation, dyspnea, pulmonary edema, and cardiac arrest. Death, coma, and encephalopathy have been reported as sequelae of these events. Excessive doses of naloxone hydrochloride in post-operative patients have resulted in significant reversal of analgesia, and have caused agitation.

Abrupt reversal of opioid effects in persons who were physically dependent on opioids has precipitated an acute withdrawal syndrome. Signs and symptoms have included: 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, tachycardia. In some patients, there may be aggressive behavior upon abrupt reversal of an opioid overdose.

In the neonate, opioid withdrawal signs and symptoms also included convulsions, excessive crying, and hyperactive reflexes.

👥 Use in Specific Populations ~3 min read ▾

8 USE IN SPECIFIC POPULATIONS

8.1Pregnancy Risk Summary The limited available data on naloxone use in pregnant women are not sufficient to inform a drug- associated risk. However, there are clinical considerations [see Clinical Considerations]. In animal reproduction studies, no embryotoxic or teratogenic effects were observed in mice and rats treated with naloxone hydrochloride during the period of organogenesis at doses equivalent to 6-times and 12-times, respectively, a human dose of 8 mg/day (two Naloxone HCl Nasal Sprays) based on body surface area comparison [see Data].

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Fetal/Neonatal adverse reactions Naloxone hydrochloride crosses the placenta, and may precipitate withdrawal in the fetus, as well as in the opioid-dependent mother [see Warnings and Precautions (5.3)].

The fetus should be evaluated for signs of distress after Naloxone HCl Nasal Spray is used. Careful monitoring is needed until the fetus and mother are stabilized. Data Animal Data Naloxone hydrochloride was administered during organogenesis to mice and rats at subcutaneous doses up to 10 mg/kg/day (equivalent to 6-times and 12-times, respectively, a human dose of 8 mg (two Naloxone HCl Nasal Sprays) based on body surface area comparison).

These studies demonstrated no embryotoxic or teratogenic effects due to naloxone hydrochloride. Pregnant female rats were administered 2 or 10 mg/kg naloxone subcutaneously from Gestation Day 15 to Postnatal day 21. There were no adverse effects on the offspring (up to 12-times a human dose of 8 mg/day (two Naloxone HCl Nasal Sprays) based on body surface area comparison).

8.2Lactation Risk Summary There is no information regarding the presence of naloxone in human milk, or the effects of naloxone on the breastfed infant or on milk production. Studies in nursing mothers have shown that naloxone does not affect prolactin or oxytocin hormone levels. Naloxone is minimally orally bioavailable.

8.4Pediatric Use The safety and effectiveness of Naloxone HCl Nasal Spray have been established in pediatric patients of all ages for known or suspected opioid overdose as manifested by respiratory and/or central nervous system depression. Use of naloxone hydrochloride in all pediatric patients is supported by adult bioequivalence studies coupled with evidence from the safe and effective use of other naloxone hydrochloride drug products. No pediatric studies were conducted for Naloxone HCl Nasal Spray.

Absorption of naloxone hydrochloride following intranasal administration in pediatric patients may be erratic or delayed. Even when the opiate-intoxicated pediatric patient responds appropriately to naloxone hydrochloride, he/she must be carefully monitored for at least 24 hours, as a relapse may occur as naloxone hydrochloride is metabolized. In opioid-dependent pediatric patients, (including neonates), administration of naloxone hydrochloride may result in an abrupt and complete reversal of opioid effects, precipitating an acute opioid withdrawal syndrome.

Neonatal opioid withdrawal syndrome, unlike opioid withdrawal syndrome in adults, may be life-threatening, if not recognized, and should be treated according to protocols developed by neonatology experts [see Warnings and Precautions (5.3)]. In settings such as in neonates with known or suspected exposure to maternal opioid use, where it may be preferable to avoid the abrupt precipitation of opioid withdrawal symptoms, consider use of an alternate naloxone-containing product that can be dosed according to weight and titrated to effect.

Also, in situations where the primary concern is for infants at risk for opioid overdose, consider whether the availability of alternate na… [Excerpted — this section continues on DailyMed.]

🧬 Clinical Pharmacology ~2 min read ▾

12 CLINICAL PHARMACOLOGY C19H21NO4●HCl M.W. 363.84 Naloxone hydrochloride, an opioid antagonist, occurs as a white to slightly off-white powder, and is soluble in water, in dilute acids, and in strong alkali; slightly soluble in alcohol; practically insoluble in ether and in chloroform. Each Naloxone HCl Nasal Spray contains a 4 mg single dose of naloxone hydrochloride (equivalent to 3.6 mg of naloxone) in a 0.1 mL (100 microliter) aqueous solution.

Inactive ingredients include benzalkonium chloride (preservative), disodium ethylenediaminetetraacetate (chelating agent), sodium chloride, hydrochloric acid to adjust pH, and purified water. The pH range is 3.5 to 5.5. The median naloxone tmax after intranasal administration of naloxone hydrochloride nasal spray, one nasal spray in one nostril (2 mg or 4 mg) or two nasal sprays as one spray in each nostril (4 mg or 8 mg), was not significantly different compared to the 0.4 mg dose of naloxone hydrochloride intramuscular injection (Table 1).

The dose normalized relative bioavailability of one dose (2 mg or 4 mg) or two doses (4 mg or 8 mg) of naloxone hydrochloride nasal spray as compared to the 0.4 mg dose of naloxone hydrochloride administered by intramuscular injection was 52%, 44%, 54%, and 43%, respectively. Distribution Following parenteral administration, naloxone is distributed in the body and readily crosses the placenta. Plasma protein binding occurs but is relatively weak.

Plasma albumin is the major binding constituent, but significant binding of naloxone also occurs to plasma constituents other than albumin. It is not known whether naloxone is excreted into human milk. Elimination Following a single intranasal administration of naloxone hydrochloride nasal spray (2 mg or 4 mg dose of naloxone hydrochloride), the mean plasma half-life of naloxone in healthy adults was approximately 1.85 (33% CV) hours and 2.08 (30% CV) hours; respectively, which was longer than that observed after administrations of a 0.4 mg naloxone hydrochloride intramuscular injection, where the half-life was 1.24 hours (26% CV).

In a neonatal study of naloxone hydrochloride injection, the mean (± SD) plasma half-life was observed to be 3.1 (± 0.5) hours. Metabolism Naloxone hydrochloride is metabolized in the liver, primarily by glucuronide conjugation, with naloxone-3-glucoronide as the major metabolite. Excretion After an oral or intravenous dose, about 25-40% of naloxone is excreted as metabolites in urine within 6 hours, about 50% in 24 hours, and 60-70% in 72 hours.

CLINICAL P 1 CLINICAL P2

📦 How Supplied / Storage and Handling 168 words ▾

16 HOW SUPPLIED/STORAGE AND HANDLING

16.1How Supplied NDC 51662-1620-1 NALOXONE HCl NASAL SPRAY 4mg/.1mL 1-PACK UNBOXED, SINGLE SPRAY DEVICE NDC 51662-1620-2 NALOXONE HCl NASAL SPRAY 4mg/.1mL 2-PACK BOXED. EACH BLISTER PACK IS A SINGLE SPRAY DEVICE Naloxone HCl Nasal Spray is not made with natural rubber latex.

16.2Storage and Handling Store Naloxone HCl Nasal Spray in the blister and cartons provided. Store below 77°F (25°C). Excursions permitted up to 104°F (40°C).

Do not freeze or expose to excessive heat above 104°F (40°C). Protect from light. Naloxone HCl Nasal Spray freezes at temperatures below 5°F (-15°C).

If this happens, the device will not spray. If Naloxone HCl Nasal Spray is frozen and is needed in an emergency, do NOT wait for Naloxone HCl Nasal Spray to thaw. Get emergency medical help right away.

However, Naloxone HCl Nasal Spray may be thawed by allowing it to sit at room temperature for 15 minutes, and it may still be used if it has been thawed after being previously frozen.

📋 Description 122 words ▾

11 DESCRIPTION Naloxone HCl Nasal Spray is a pre-filled, single dose intranasal spray. Chemically, naloxone hydrochloride is the hydrochloride salt of 17-Allyl-4,5α-epoxy-3,14-dihydroxymorphinan-6-one hydrochloride with the following structure: C19H21NO4●HCl M.W. 363.84 Naloxone hydrochloride, an opioid antagonist, occurs as a white to slightly off-white powder, and is soluble in water, in dilute acids, and in strong alkali; slightly soluble in alcohol; practically insoluble in ether and in chloroform.

Each Naloxone HCl Nasal Spray contains a 4 mg single dose of naloxone hydrochloride (equivalent to 3.6 mg of naloxone) in a 0.1 mL (100 microliter) aqueous solution. Inactive ingredients include benzalkonium chloride (preservative), disodium ethylenediaminetetraacetate (chelating agent), sodium chloride, hydrochloric acid to adjust pH, and purified water. The pH range is 3.5 to 5.5.

STRUCTURE

💬 Patient Medication Information ~3 min read ▾

PATIENT INFORMATION PATIENT INFORMATION Naloxone (nal-OKS-one) Hydrochloride Nasal Spray You and your family members or caregivers should read this Patient Information leaflet before an opioid emergency happens. This information does not take the place of talking with your healthcare provider about your medical condition or your treatment. What is the most important information I should know about Naloxone HCl Nasal Spray?

Naloxone HCl Nasal Spray is used to temporarily reverse the effects of opioid medicines. The medicine in Naloxone HCl Nasal Spray has no effect in people who are not taking opioid medicines. Always carry Naloxone HCl Nasal Spray with you in case of an opioid emergency.

1. Use Naloxone HCl Nasal Spray right away if you or your caregiver think signs or symptoms of an opioid emergency are present, even if you are not sure, because an opioid emergency can cause severe injury or death. Signs and symptoms of an opioid emergency may include: • unusual sleepiness and you are not able to awaken the person with a loud voice or by rubbing firmly on the middle of their chest (sternum) • breathing problems including slow or shallow breathing in someone difficult to awaken or who looks like they are not breathing • the black circle in the center of the colored part of the eye (pupil) is very small, sometimes called “pinpoint pupils,” in someone difficult to awaken 2.

Family members, caregivers, or other people who may have to use Naloxone HCl Nasal Spray in an opioid emergency should know where Naloxone HCl Nasal Spray is stored and how to give Naloxone HCl Nasal Spray before an opioid emergency happens. 3. Get emergency medical help right away after giving the first dose of Naloxone HCl Nasal Spray.

Rescue breathing or CPR (cardiopulmonary resuscitation) may be given while waiting for emergency medical help. 4. The signs and symptoms of an opioid emergency can return after Naloxone HCl Nasal Spray is given.

If this happens, give another dose after 2 to 3 minutes using a new Naloxone HCl Nasal Spray and watch the person closely until emergency help is received. What is Naloxone HCl Nasal Spray? • Naloxone HCl Nasal Spray is a prescription medicine used for the treatment of an opioid emergency such as an overdose or a possible opioid overdose with signs of breathing problems and severe sleepiness or not being able to respond. • Naloxone HCl Nasal Spray is to be given right away and does not take the place of emergency medical care.

Get emergency medical help right away after giving the first dose of Naloxone HCl Nasal Spray, even if the person wakes up. • Naloxone HCl Nasal Spray is safe and effective in children for known or suspected opioid overdose. Who should not use Naloxone HCl Nasal Spray? Do not use Naloxone HCl Nasal Spray if you are allergic to naloxone hydrochloride or any of the ingredients in Naloxone HCl Nasal Spray.

See the end of this leaflet for a complete list of ingredients in Naloxone HCl Nasal Spray. What should I tell my healthcare provider before using Naloxone HCl Nasal Spray? Before using Naloxone HCl Nasal Spray, tell your healthcare provider about all of your medical conditions, including if you: • have heart problems • are pregnant or plan to become pregnant.

Use of Naloxone HCl Nasal Spray may cause withdrawal symptoms in your unborn baby. Your unborn baby should be examined by a healthcare provider right away after you use Naloxone HCl Nasal Spray. • are breastfeeding or plan to breastfeed. It is not known if Naloxone HCl Nasal Spray passes into your breast milk.

Tell your healthcare provider about the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. How should I use Naloxone HCl Nasal Spray? Read the “Instructions for Use” at the end of this Patient Information leaflet for detailed information about the right way to use Naloxone HCl Nasal Spray. • Use Naloxone HCl Nasal Spray exactly as prescribed by your healthcare provider. • Each… [Excerpted — this section continues on DailyMed.]

🧪 Nonclinical Toxicology 131 words ▾

13 NONCLINICAL TOXICOLOGY

13.1Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term animal studies to evaluate the carcinogenic potential of naloxone have not been completed. Mutagenesis Naloxone was weakly positive in the Ames mutagenicity and in the in vitro human lymphocyte chromosome aberration test but was negative in the in vitro Chinese hamster V79 cell HGPRT mutagenicity assay and in the in vivo rat bone marrow chromosome aberration study. Impairment of Fertility Male rats were treated with 2 or 10 mg/kg naloxone for 60 days prior to mating.

Female rats treated for 14-days prior to mating and throughout gestation with the same doses of naloxone (up to 12-times a human dose of 8 mg/day (two naloxone hydrochloride nasal sprays) based on body surface area comparison). There was no adverse effect on fertility.

📖 Instructions for Use ~3 min read ▾

INSTRUCTIONS FOR USE Instructions for Use Naloxone (nal-OKS-one) Hydrochloride Nasal Spray You and your family members or caregivers should read the Instructions for Use that comes with Naloxone HCl Nasal Spray before using it. Talk to your healthcare provider if you and your family members or caregivers have any questions about the use of Naloxone HCl Nasal Spray. Use Naloxone HCl Nasal Spray for known or suspected opioid overdose in adults and children.

Important: For use in the nose only. • Do not remove or test the Naloxone HCl Nasal Spray until ready to use. • Each Naloxone HCl Nasal Spray has 1 dose and cannot be reused. • You do not need to prime Naloxone HCl Nasal Spray. How to use Naloxone HCl Nasal Spray: Step 1. Lay the person on their back to receive a dose of Naloxone HCl Nasal Spray.

Step 2. Remove Naloxone HCl Nasal Spray from the box. Peel back the tab with the circle to open the Naloxone HCl Nasal Spray.

Note: Naloxone HCl Nasal Spray freezes at temperatures below 5°F (-15°C). If this happens, the device will not spray. Get emergency medical help right away if this happens.

Do not wait for Naloxone HCl Nasal Spray to thaw. Naloxone HCl Nasal Spray may still be used if it has been thawed after being previously frozen. Step 3.

Hold the Naloxone HCl Nasal Spray with your thumb on the bottom of the plunger and your first and middle fingers on either side of the nozzle. Step 4. Tilt the person’s head back and provide support under the neck with your hand.

Gently insert the tip of the nozzle into one nostril until your fingers on either side of the nozzle are against the bottom of the person’s nose. Step 5. Press the plunger firmly to give the dose of Naloxone HCl Nasal Spray.

Step 6. Remove the Naloxone HCl Nasal Spray from the nostril after giving the dose. What to do after Naloxone HCl Nasal Spray has been used: Step 7.

Get emergency medical help right away. • Move the person on their side (recovery position) after giving Naloxone HCl Nasal Spray. • Watch the person closely. • If the person does not respond by waking up, to voice or touch, or breathing normally another dose may be given. Naloxone HCl Nasal Spray may be dosed every 2 to 3 minutes, if available. • Repeat Steps 2 through 6 using a new Naloxone HCl Nasal Spray to give another dose in the other nostril. If additional Naloxone HCl Nasal Sprays are available, Steps 2 through 6 may be repeated every 2 to 3 minutes until the person responds or emergency medical help is received.

Step 8. Put the used Naloxone HCl Nasal Spray back into its box. Step 9.

Throw away (dispose of) the used Naloxone HCl Nasal Spray in a place that is away from children. How should I store Naloxone HCl Nasal Spray? • Store below 77°F (25°C). • Excursions permitted up to 104°F (40°C). • Do not freeze or expose to excessive heat above 104°F (40°C). • Keep Naloxone HCl Nasal Spray in the box until ready to use. Protect from light. • Replace Naloxone HCl Nasal Spray before the expiration date on the box.

Keep Naloxone HCl Nasal Spray and all medicines out of the reach of children. This Instructions for Use has been approved by the U.S. Food and Drug Administration.

For more information, go to www.perrigorx.com or call 1-866-634-9120. Made in Israel Manufactured by Perrigo Yeruham, Israel Distributed by Perrigo Allegan, MI 49010 2Y200 RC P J2 Rev. 11-20 I1 I2 I3 I4 I5

QUICK START GUIDE Naloxone HCl Nasal Spray 4 mg QUICK START GUIDE Opioid Overdose Response Instructions Use Naloxone Hydrochloride Nasal Spray for known or suspected opioid overdose in adults and children. Important: For use in the nose only. Do not remove or test the Naloxone HCl Nasal Spray until ready to use.

1 Identify Opioid Overdose and Check for Response Ask person if he or she is okay and shout name. Shake shoulders and firmly rub the middle of their chest. Check for signs of opioid overdose: • Will not wake up or respond to your voice or touch • Breathing is very slow, irregular, or has stopped • Center part of… [Excerpted — this section continues on DailyMed.]

📄 Package Label / Principal Display Panel ~1 min read ▾

PRINCIPAL DISPLAY PANEL - NDC 51662-1620-1 NALOXONE HCl NASAL SPRAY 4mg/.1mL 1-PACK UNBOXED Rx Only NDC 51662-1620-1 Naloxone HCl Nasal Spray 4 mg Important: FOR USE IN THE NOSE ONLY. Use Naloxone HCl Nasal Spray for known or suspected opioid overdose in adults and children. Do not remove or test the Naloxone HCl Nasal Spray until ready to use.

ONE PACK This package contains one (1) 4-mg doses of naloxone HCl nasal spray. 0.1 mL intranasal spray per unit For use in the nose only CHECK PRODUCT EXPIRATION DATE BEFORE USE. Opioid Overdose Response Instructions Package Label Front Package Label Back Serialized Labeling Information OR1A ORI1B Front pback RFID Label

PRINCIPAL DISPLAY PANEL - NDC 51662-1620-2 NALOXONE HCl NASAL SPRAY 4mg/.1mL 2-PACK BOXED Rx Only NDC 51662-1620-2 NALOXONE HCl NASAL SPRAY 4mg/.1mL 2-PACK BOXED Important: FOR USE IN THE NOSE ONLY. Use Naloxone HCl Nasal Spray for known or suspected opioid overdose in adults and children. Do not remove or test the Naloxone HCl Nasal Spray until ready to use.

TWO PACK This box contains two (2) 4-mg doses of naloxone HCl nasal spray. 0.1 mL intranasal spray per unit For use in the nose only CHECK PRODUCT EXPIRATION DATE BEFORE USE. Opioid Overdose Response Instructions CARTON LABELING INDIVIDUAL PACKAGE FRONT INDIVIDUAL PACKAGE BACK SERILIZED LABELING ORI1AA 1BB CARTON FRONT BACK RFID Label

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗

Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Naloxone HCl — the program that covers self-administered drugs. 13 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Naloxone HCl. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$389.4K
Claims incl. refills
10.2K
Beneficiaries
9.2K
Spend / beneficiary
$42.54
Spend / claim
$38.07
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) — Not published for this NDC The labeler did not submit a structured excipient list, or no SPL is available.
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data — Not published for this NDC Applies only to products approved under an NDA/ANDA; many listings are out of scope.
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The form printed on the packaging and shown on DailyMed is the one the FDA registered. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero and the dashes are dropped. The Identity section at the top of this page lists each form of this code.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by HF Acquisition Co LLC, DBA HealthFirst. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 2 vials (51662-1620-02). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
HF Acquisition Co LLC, DBA HealthFirst is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.