Narcan Dose: IV And Nasal Spray Dosage. Naloxone Overdose

Last Updated: June 3, 2020

Authored by Nena Messina, Ph.D.

Naloxone is a medication that usually comes in preassembled devices, eliminating a patient’s need to measure Narcan doses before the administration. However, the knowledge about how naloxone dosing occurs can be life-saving in situations where Evzio and Narcan are not available. Besides, it is still necessary to know what the maximum naloxone dosage is and what symptoms might appear if a person overdoses on it.

Narcan Dose For Opioid Overdose

Considering what Narcan is, it can be used for various purposes, all of which require a specific dosage. Narcan dosing for opioid overdose depends on a patient’s weight, the route of administration, and the severity of the overdose.


Initial Dose
The standard initial dose of the drug is one 4 mg spray intranasally or 0.4 mg to 2 mg IV. If Evzio auto-injector is used, the initial dosing is a single injection that will contain either 0.4 mg or 2 mg of naloxone, depending on the strength of the solution.
Evzio Auto-Injector
In the clinical setting, it is recommended to begin naloxone infusion for an opioid overdose at 0.004 mg/mL intravenously. Other routes of administration include intramuscular and subcutaneous (IM/SC) injections.

Narcan Nasal Spray
Narcan nasal spray dose for opioid overdose reversal is 4 mg. It is less bioavailable than Evzio; hence, more of the drug is needed to achieve the desired effects. Although many patients prefer the nasal spray due to a lower Narcan price, there are no significant differences in effectiveness between the nasal spray and Evzio.


Children And Adolescents From 5 To 17 Years Of Age

Naloxone pediatric dose of the nasal spray is the same as for adults. The initial nasal Narcan dose is 4 mg.

The standard dose of Evzio is 0.4 intramuscularly. It can be repeated every 2-3 minutes until help arrives.

The initial IV dose for children is 0.01 mg/kg. It may be increased to 0.1 mg/kg if a child doesn’t respond. It is recommended to give 2 mg of naloxone in total for the complete reversal of narcotic effects.

narcan pediatric dose

Infants And Children Younger Than 5 Years Of Age

Narcan nasal dose for infants is 4 mg. To achieve the complete reversal of narcotic effects, 0.1 mg/kg IV or IO (intraosseous infusion) is recommended. The initial dose is 0.01 mg/kg IV, IM, or SC.


The recommended initial dose is 0.01 mg/kg IV. 0.1 mg/kg IV is recommended to achieve the complete reversal of narcotic effects. Intramuscular administration is also acceptable if IV is not available.

Narcan Dose For Opioid Reversal

Although it is most frequently applied to combat an opioid overdose, Narcan uses include reversal of the effects of anesthesia and respiratory depression after therapeutic opioid use.


Reversal Of Respiratory Depression After Therapeutic Opioid Use

The initial Narcan IV dose is 0.1 to 0.2 mg IV. Additional administration of the drug may be necessary at 1 to 2 hours after the desired results were achieved.

Postoperative Opioid Depression

The initial dosing is 0.1 to 0.2 mg intravenous Narcan injection. Also, a 0.004 mg/mL solution can be administered via naloxone infusion. Larger doses may result in increased blood pressure and reduced analgesic effects.


Post-anesthesia (Acute) Opioid Reversal

The initial Narcan pediatric dose is 0.005 mg to 0.01 mg IV. It may be repeated every 2-3 minutes. A concentration of 0.004 mg/mL can be administered by Narcan infusion.

Reversal Of Respiratory Depression After Therapeutic Opioid Use

The recommended Narcan dosage to reverse respiratory depression is 1 to 5 mcg/kg IV.

Maximum Safe Dosage Of Narcan

The max dose of Narcan is established to be 10 mg per day. If this limit is reached, but no changes to a person’s condition occur, it is recommended to stop naloxone treatment and look for issues other than the overdose.

max dose of narcan

Nasal Narcan dose of 4mg is usually sufficient to reverse respiratory depression caused by an opioid overdose. However, some patients remain unresponsive and require repeated administration before their breathing is restored. Several doses may also be required to assist breathing until emergency help arrives, considering how long naloxone stays in one’s system. Dosing can be repeated until the amount of 10 mg is reached. Narcan dose IV is recommended to start at 0.4 to 2 mg.

How Many Doses Of Narcan Can One Give?

Administration Geriatric
>65 yr
25-64 yr
10-24 yr
5-12 yr
1-4 yr
2mo – 1yr
0-2 mo
2 mg 2 mg 2 mg 2 mg 0.1 mg/kg 0.1 mg/kg 0.1 mg/kg
Spray 1 spray
(4 mg)
1 spray
(4 mg)
1 spray
(4 mg)
1 spray
(4 mg)
1 spray
(4 mg)
1 spray
(4 mg)
1 spray
(4 mg)

Naloxone Overdose: Symptoms And Occurrence

Although it is a prescription medication, Narcan OTC can be obtained in 42 states. It leads many people to wonder whether it is possible to overdose on this medication and how dangerous a Narcan overdose can be.

Naloxone overdose is technically possible at dosing that is significantly larger than the recommended ones. It may happen if a patient has received several doses of the drug prior to an emergency medical staff arrival. If a person does overdose, they may experience more acute naloxone side effects, including potential cardiac and liver problems.

Naloxone LD50

LD50 for Narcan is the lethal naloxone dose in 50% of the animals tested. This value can be useful to assess the toxicity of the medication. LD50 in IV administration for mice is 150 mg/kg. LD50 in IV administration for rats is 109 mg/kg.

Awareness Of Current Dosing Is Critical

A standard Narcan dose contains 4 mg of the medication and proves sufficient to restore breathing in many cases. It remains the same for adults, children of all ages, and even infants. The maximum dose of Narcan is 10 mg, meaning that a person can safely receive two administrations of the nasal spray. Still, after drug administration, a person requires further medical aid in the drug rehab facilities. The medical staff there can provide correct treatment and after-care support.

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Published on: June 19th, 2019

Updated on: June 3rd, 2020

About Author

Nena Messina, Ph.D.

Nena Messina is a specialist in drug-related domestic violence. She devoted her life to the study of the connection between crime, mental health, and substance abuse. Apart from her work as management at addiction center, Nena regularly takes part in the educational program as a lecturer.


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