Facts about Naloxone

Naloxone is an opioid antagonist, approved by the Food and Drug Administration (FDA) to manage opioid overdose.1 By competitively blocking opioid receptors, naloxone can prevent opioid agonist drugs like heroin, morphine, fentanyl, oxycodone, and hydrocodone from continuing to bind to and activate those receptors; during an overdose, when delivered in sufficient doses, naloxone may kick the already-circulating opioid agonist drugs off these receptors to halt their potentially-deadly pharmacologic activity such as severe respiratory depression.

An opioid overdose can occur for several reasons, including:2

  • A person takes too many prescription painkillers (e.g., such as in a setting of inadequate pain management).
  • An opioid-naïve person takes an opioid prescribed for someone else (e.g., children getting into a medicine cabinet).
  • An individual struggles with substance abuse and uses too large a dose of an opioid drug—either illicit or prescription—in an attempt to elicit a euphoric high.
  • An intentional overdose (i.e., suicidal intent).
  • A polysubstance user inadvertently decreases the margin of safety for overdose by mixing opioids with central nervous system depressing drugs such as benzodiazepines (e.g., Valium, Klonopin, Xanax, etc.) or alcohol.

How Naloxone Is Used

The drug is available in several formulations, including a metered nasal spray that has seen increasingly widespread use in recent years. Other formulations can be injected subcutaneously, intramuscularly, or intravenously.3 Narcan is perhaps the most widely recognized brand name for naloxone currently on the market.

This opioid antagonist is also part of the combination drug Suboxone—a medication prescribed to treat opioid use disorder. The primary active component of Suboxone (and similar formulations such as Bunavail and Zubsolv) is buprenorphine, a partial opioid agonist. The buprenorphine component of these treatment drugs bind to and activate opioid receptors to stabilize someone in recovery from opioid addiction by easing or preventing withdrawal symptoms. As a partial agonist, it should not induce a high in opioid-tolerant individuals when used as directed.

Naloxone is added to Suboxone to minimize the abuse potential of the drug to get high. When taken orally—the intended route of therapeutic use—Suboxone reduces withdrawal symptoms; when attempts are made to dissolve and inject the medication, the naloxone component should result in some opioid receptor blockade, which can result in withdrawal in people with significant dependence to opioid drugs such as heroin and other full opioid receptor agonists.4

Naloxone to Reverse Opioid Overdoses

Though indispensable for preventing overdose deaths, naloxone should not be treated as an alternative to emergency medical treatment. It can be administered to temporarily reverse an opioid overdose but, depending on the amount of opioid drugs present, as well as the potency of those opioids, it may not always stop the overdose completely. Naloxone will do nothing to reverse an overdose involving other classes of drugs, including benzodiazepines.1 After naloxone administration, the recipient should be monitored until emergency medical personnel are able to assume continued overdose management. At least 2 hours of observation may be necessary to make sure that respiratory depression does not return after the initial dose of naloxone is given.5

Opioid overdose is a life-threatening medical emergency. When opioid overdose is suspected, administer naloxone if it is available and call 911 immediately. Emergency medical treatment gives the individual the best chance of surviving the overdose.

Symptoms of an opioid overdose may include:6,7

  • Marked drowsiness.
  • Loss of consciousness.
  • Small or pinpoint pupils.
  • Depressed, shallow, or irregular breathing.
  • Slowed or stopped heartbeat.
  • Pale, clammy skin.
  • Limp muscle tone.
  • Bluish tint to the skin around the lips and fingernails.

For years, first responders and medical professionals were the only people authorized to use naloxone. Now, however, laws are beginning to change. An estimated 128 people die each day from opioid overdose involving either prescription or illicit drugs, according to the Centers for Disease Control and Prevention (CDC).8 Development of NARCAN and EVZIO—a nasal spray and an auto-injectable, respectively—has allowed more non-medical personnel to administer naloxone to a person in opioid overdose in the hopes of saving some of these lives.5

National Laws and Changing Attitudes toward Naloxone

Doctors throughout the country are allowed to prescribe naloxone to those who use prescription opioids, but as the opioid abuse epidemic continues to take many lives, all 50 states and the District of Columbia have enacted changes to state laws to increase naloxone access.12 Some drug store chains have taken steps to make naloxone available over the counter. This means that people who may be struggling with heroin addiction, or another kind of opioid addiction, can purchase packages of naloxone, no questions asked. Two major drug store retail chains, CVS and Walgreens, now provide naloxone without a personal prescription, making naloxone available in all stores throughout the U.S. and Washington, D.C.5

Relatively recent data from the World Health Organization indicates that approximately 50,000 naloxone kits distributed through local opioid overdose prevention programs have resulted in more than 10,000 uses to reverse instances of overdose in the United States.9

As of 2018, Good Samaritan laws in all but 5 states in the U.S. were providing immunity or other legal protection those who call emergency responders if they witness an opioid overdose. This is an important policy development because, in many instances, the person who witnesses the overdose is also someone struggling with opioid addiction, so they may have purchased or helped administer the opioid that led to the overdose.10Good Samaritan laws protect these people from prosecution for possessing or taking drugs.

As of 2018, the states that did not have Good Samaritan Laws in place included:

  • Wyoming.
  • Maine.
  • Kansas.
  • Oklahoma.
  • Texas.

Changing Laws for Naloxone Access in Texas

In 2015, Texas passed Senate Bill 1462, which changed provisions around naloxone availability and administration. The law went into full effect in September 2015.11 SB 1462 allowed prescribers to give naloxone prescriptions to those who take narcotic painkillers and to also prescribe the medicine to family members, friends, or unofficial caregivers. The prescription can be in the form of a standing order, meaning the person does not have to fill the prescription immediately; instead, the order allows the person to acquire naloxone in an emergency situation from a local pharmacy. SB 1462 also states that any naloxone prescription in the state of Texas has a legitimate medical purpose.

Emergency responders have greater access to naloxone, including:

  • Emergency services personnel.
  • Firefighters.
  • Emergency room personnel.
  • Volunteer responders.

SB 1462 also gives immunity to prescribers and dispensers of naloxone in both civil and criminal court, as long as the professional acts in good faith and with reasonable care. This is in regard to both prescribing or not prescribing naloxone, and filling or not filling the prescription.

The Texas Pharmacy Association (TPA) expanded the standing order doctrine, starting in August 2016. The professional organization requires pharmacists to have a one-hour training course in naloxone before they can administer the medicine, but TPA expanded access to the accreditation as part of their Saving Lives Initiative.

Further, the law allows nonprofits, medical centers, rehabilitation centers, and other organizations to distribute naloxone to anyone who may use it to save lives, as long as the organization does not receive financial gain.

Most importantly, people witnessing an overdose can administer naloxone without suffering criminal penalty, civil liability, and sanction under professional statutes. This is an essential step toward greater Good Samaritan laws. In 2016, news reporting indicated that naloxone was available in 715 Walgreens across the state.


  1. Substance Abuse and Mental Health Services Administration (SAMHSA). (2019). Medication-Assisted Treatment—Naloxone.
  2. SAMHSA. (2019). Opioid Overdose.
  3. Hamilton, RJ. (2019). Tarascon Pocket Pharmacopoeia, 2019 Deluxe Lab-Coat Edition. Jones & Bartlett Learning.
  4. U.S. Department of Health and Human Services—Food & Drug Administration. (2019). Labelling-Medication Guide: Suboxone.
  5. National Institute on Drug Abuse. (2020). Opioid Overdose Reversal with Naloxone (Narcan, Evzio).
  6. U.S. National Library of Medicine—MedlinePlus. (2016). Naloxone Injection.
  7. U.S. National Library of Medicine—MedlinePlus. (2020). Opioid Overdose.
  8. Centers for Disease Control and Prevention (CDC). (2020). Opioid Overdose—Understanding the Epidemic.
  9. World Health Organization. (2018). Management of Substance Abuse—Information Sheet on Opioid Overdose.
  10. Prescription Drug Abuse Policy System. (n.d.). Good Samaritan Overdose Prevention Laws.
  11. Texas Medical Association. (2015). Youth Safeguards, Budget Boons—Legislature, Governor Enact Laws to Address TMA Public Health Concerns.
  12. The Network for Public Health Law. (2020). Characteristics of Statewide Naloxone Distribution Mechanisms.