Narcan (Naloxone): Overview and Practice Questions (2025)

Narcan, the brand name for naloxone, is a fast-acting medication that can rapidly reverse an opioid overdose by displacing opioids from brain receptors and restoring breathing. Widely used by first responders, clinicians, and community programs, it is available as an intranasal spray as well as intramuscular and intravenous injections.

Because opioid toxicity suppresses ventilatory drive, Narcan is directly relevant to respiratory care, where timely airway support, oxygenation, and monitoring are critical. When given promptly, it can prevent hypoxic injury and death, buying essential time for definitive treatment.

This article explains how Narcan works, when and how to administer it, what to watch for after reversal, and the key role respiratory therapists play in patient safety and education.

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What is Narcan?

Narcan is the brand name for naloxone, an opioid antagonist that rapidly reverses opioid-induced respiratory and central nervous system depression. It competitively displaces opioids from μ receptors, restoring breathing within minutes. Formulations include intranasal spray, intramuscular, and intravenous routes; onset is ~1–3 minutes (IV fastest) and effect lasts 30–90 minutes, so repeat dosing may be needed, especially with fentanyl or methadone.

Narcan is safe if given when no opioids are present, but can precipitate acute withdrawal in dependent users. Use in any suspected overdose with slow or absent breathing, call emergency services, and monitor oxygenation and ventilation.

Administration

Narcan can be administered in several forms:

• Intranasal spray (most common in pre-hospital settings and public use)
• Intramuscular injection
• Intravenous injection

Note: Its effects typically begin within 2–3 minutes and last 30–90 minutes, which may require repeated dosing depending on the opioid involved, especially with long-acting opioids like methadone or fentanyl.

Why is Narcan Relevant to Respiratory Therapists?

Opioid overdose is a direct cause of respiratory depression, which can lead to hypoxia, brain injury, or death if untreated. Respiratory therapists are often part of rapid response or code teams in hospitals, emergency departments, and critical care settings. They may be called upon to:

• Assist in airway management for patients with opioid-induced respiratory depression
• Support ventilation until Narcan takes effect
• Monitor oxygenation and ventilation after Narcan administration
• Educate patients and families about overdose risks and prevention

Note: Because Narcan rapidly reverses the respiratory effects of opioids, it is directly tied to the primary focus of respiratory care—maintaining adequate oxygen and carbon dioxide exchange.

Narcan in the Field of Respiratory Care

• Emergency Response: In cases of suspected overdose, time is critical. A respiratory therapist may be among the first to respond in a hospital setting, working alongside nurses and physicians to administer Narcan and provide ventilatory support.
• Post-Resuscitation Monitoring: After Narcan administration, patients may experience acute withdrawal symptoms, agitation, or recurrent respiratory depression once the medication wears off. Respiratory therapists play a key role in continuous monitoring and ensuring oxygen delivery remains adequate.
• Critical Care: In intensive care units, some patients may require mechanical ventilation after a severe overdose. Narcan’s role here is part of a broader respiratory support plan that includes ventilator management and gradual weaning once the patient stabilizes.
• Education and Advocacy: Many respiratory therapists work in community health programs, outpatient clinics, or public health initiatives. They can help train individuals on how to recognize overdose signs and use Narcan, especially in high-risk populations.

Safety Considerations and Limitations

• Narcan is safe for individuals with no opioids in their system—it will not cause harm if given mistakenly during a suspected overdose.
• The medication’s effects are temporary, so emergency medical care is still essential after administration.
• In some cases, the sudden reversal of opioids can cause acute withdrawal, which can be distressing but is not typically life-threatening.
• High-potency synthetic opioids may require multiple doses due to their strong and long-lasting effects.

Narcan Practice Questions

1. An adult is brought to the emergency department unresponsive with irregular breathing and pinpoint pupils after a suspected overdose. What should the respiratory therapist recommend administering?  
Naloxone HCl (Narcan)

2. A 39-year-old female is intubated during CPR, and no IV access is available. The physician suspects a narcotic overdose. What is an alternative route to administer Naloxone?  
Endotracheal tube

3. A 21-year-old male is brought to the ER unresponsive, and a family member mentions he has depression. The nurse suspects an overdose. What should the respiratory therapist recommend?  
Naloxone

4. What must a respiratory therapist monitor for in a patient using narcotics?
CNS depression, orthostatic hypotension, tolerance, dependence, nausea, vomiting, constipation, delayed response time, and enhanced CNS depression when combined with alcohol

5. What is Narcan primarily used for in clinical practice?  
To reverse the effects of opioid-induced sedation, respiratory depression, and hypotension

6. What is the therapeutic purpose of Narcan?  
To treat respiratory depression and other depressant effects caused by narcotic overdose

7. What is the mechanism of action of Narcan?  
It blocks the effects of narcotics by competing for opioid receptor sites

8. What are common side effects of Narcan?  
Tremors, sweating, hypertension, tachycardia, nausea, vomiting, reversal of analgesia, dysrhythmias, elevated PTT, and bleeding

9. What interventions should be implemented when administering Narcan?  
Monitor vital signs and signs of bleeding continuously

10. What drug class does Narcan belong to?  
Opiate antagonist

11. How does Narcan work at the receptor level?  
It is a pure opioid antagonist that displaces opioids at receptor sites

12. What is the primary indication for Narcan?  
Opiate overdose resulting in respiratory depression

13. What is a known contraindication for using Narcan?  
Hypersensitivity to naloxone or any component of the formulation

14. What should be used with caution when administering Narcan to patients with cardiovascular disease?  
Narcan may cause adverse cardiac effects such as arrhythmias and should be administered cautiously

15. What withdrawal-related symptoms can Narcan cause in opioid-dependent patients?  
Tremors, seizures, agitation, nausea, vomiting, and other acute withdrawal symptoms

16. What is a serious potential pulmonary adverse reaction of Narcan?  
Pulmonary edema

17. What are the cardiovascular adverse reactions associated with Narcan?  
Hypertension and ventricular arrhythmias

18. What are some neurologic and systemic adverse effects of Narcan?  
Tremor, seizures, and opioid withdrawal symptoms

19. Are there any significant drug interactions with Narcan?  
No known significant drug interactions

20. What is the recommended adult dosage and route for Narcan?  
0.4–2 mg IV/IO/IM/SQ every 2–3 minutes, up to 10 mg max; or 2 mg IN (1 mL per nostril) every 3–5 minutes, up to 10 mg

21. What is the recommended pediatric dose for Narcan in patients under 5 years old or weighing less than 20 kg?  
0.1 mg/kg IV/IO/IM/SQ/IN every 2–3 minutes, up to a maximum of 10 mg

22. When respiratory compromise is present, what is the priority over naloxone administration?  
Ventilatory support

23. Besides overdose treatment, what are other uses of Narcan?  
To reduce or avoid side effects caused by opioids

24. How is Narcan classified pharmacologically?  
Opioid antagonist

25. Is a prescription required to obtain Narcan?  
Yes, it is prescription only

26. Is Narcan considered a controlled substance?  
No, it is not a controlled drug

27. What is the therapeutic action of Narcan in a patient experiencing opioid overdose?  
Improvement of respiratory rate

28. What type of drug is Narcan classified as?  
Opioid antagonist

29. What is the generic name for Narcan?  
Naloxone

30. What is the brand name of naloxone nasal spray?  
Narcan

31. What are common side effects of Narcan and symptoms of narcotic withdrawal?  
Flushing, dizziness, tiredness, weakness, nervousness, restlessness, irritability, and body aches

32. What are the clinical indications for administering Narcan?  
Suspected or known narcotic overdose

33. What are the acceptable routes for administering Narcan?  
IV push, intraosseous (IO), intramuscular (IM), intranasal (IN), and endotracheal (ET)

34. What receptors does Narcan block to reverse the effects of opioids?  
Mu and kappa receptors

35. What is a known contraindication for using Narcan?  
Hypersensitivity to naloxone or any of its ingredients

36. What are some adverse effects associated with Narcan administration?  
Opioid withdrawal, rapid loss of analgesia, increased heart rate, blood pressure, respiratory rate, tremors, hyperventilation, and return of pain

37. What types of opioids can Narcan reverse the effects of?  
Natural and synthetic opioids including propoxyphene, methadone, and mixed agonist-antagonist analgesics like nalbuphine, pentazocine, butorphanol, and cyclazocine

38. In addition to overdose reversal, how may Narcan be used in critical care settings?  
As an adjunctive agent to increase blood pressure in septic shock

39. What should be included in patient teaching about Narcan?  
Explain that it is used to reverse CNS and respiratory depression due to suspected opioid overdose

40. True or False: Naloxone and other opioid antagonists can replace emergency medical care in overdose situations.  
False

41. What is an example of an opioid antagonist used to reverse overdose effects?  
Naloxone

42. In what forms does naloxone typically come in opioid recovery kits?  
Injection and nasal spray

43. True or False: Opioid withdrawal symptoms are not a reason to avoid naloxone use in life-threatening situations.  
True

44. Which of the following statements is true about fentanyl?  
It is a highly potent and often illegally used opioid formulation

45. What are the most common side effects of opioid use?  
Slowed or shallow breathing, weak pulse, and low blood pressure

46. Without oxygen or medical intervention, how soon can brain damage occur during an opioid overdose?  
3–5 minutes

47. What are appropriate steps when using naloxone during an opioid overdose?  
Place the person in recovery position, Call 911 and/or campus MERT, Continue CPR as needed, Be prepared for erratic behavior, Use double gloves and a mask for rescue breathing, and Administer a second dose if no response in 2–3 minutes.

48. True or False: Naloxone nasal spray is administered into one nostril without priming, using the red plunger to deliver the full dose.  
True

49. Who should be notified after using Naloxone (Narcan) on campus?  
Medical Campus Emergency Response Team (MERT), School Resource Officer (SRO), EMS/911, Campus Nurse, Campus Administration, CPI-trained individuals

50. Where is Narcan currently stored on MISD campuses?  
Inside the main campus AED cabinet (indicated with a sign on the outside)

51. True or False: The person should be laid on their back when administering Narcan.  
True

52. Which of the following is an appropriate action to take when assisting someone who is overdosing?  
Perform rescue breathing and call an ambulance

53. True or False: It is possible to overdose on naloxone.  
False

54. Your risk of experiencing an opioid overdose increases when which of the following occurs?  
All of the above

55. What is Narcan primarily used for?  
Reversing a heroin or other opioid overdose

56. True or False: An opioid overdose can outlast a dose of Narcan, so someone should stay with the person for at least an hour after revival.  
True

57. After administering Narcan, what actions should you take?  
All of the above (monitor breathing, place in recovery position, call 911)

58. True or False: Amethyst Recovery Center provides Narcan nasal spray and injectable naloxone for emergency use.  
False

59. True or False: If the first dose of Narcan doesn’t work within 2–3 minutes, a second dose should be administered.  
True

60. True or False: Narcan should be administered immediately during an overdose but does not replace emergency medical care.  
True

61. What is the active ingredient in Narcan?  
Naloxone hydrochloride

62. True or False: If a patient relapses into respiratory depression after initial recovery, additional doses of Narcan may be given every 2–3 minutes until help arrives.  
True

63. True or False: You must use a new Narcan device for each dose, as each contains only one dose.
True

64. True or False: Before administering Narcan Nasal Spray, the individual should be moved to their side in the recovery position.  
False

65. In someone who regularly uses opioids, which of the following is NOT a typical symptom of opioid withdrawal after receiving Narcan?  
Decreased blood pressure

66. Which of the following are signs and symptoms of an opioid emergency?  
All of the above (slow breathing, unresponsiveness, severe sleepiness)

67. True or False: NARCAN® Nasal Spray is a prescription medicine used to treat an opioid overdose with signs such as breathing problems and unresponsiveness.  
True

68. True or False: Narcan Nasal Spray is administered by injection.  
False

69. True or False: Narcan devices can be reused for multiple individuals if only part of the dose was used.  
False

70. What are opiates and what do they do?  
They are synthetic or semi-synthetic alkaloids that act as CNS depressants, decrease pain, and increase tolerance

71. Opiates primarily affect which parts of the brain?  
The limbic system and brainstem, which influence emotions and control respiratory rate

72. What are common side effects of opiate use?  
Drowsiness, itching, dry mouth, constipation, nausea, vomiting, and miosis (pupil constriction)

73. What are typical signs and symptoms of an opioid overdose?  
Agonal respirations, respiratory arrest, cyanosis, depressed respiratory rate, miosis, and unresponsiveness with a pulse

74. Which of the following are examples of common opiates?  
Codeine, Vicodin, Morphine, Hydrocodone, Heroin

75. What is the most important factor to assess before administering Narcan?  
Presence of respiratory depression or unresponsiveness with suspected opioid use

76. What is Narcan (Naloxone) and how does it work?  
It is an opioid antagonist that may reverse CNS and respiratory depression caused by opioid overdose

77. In which situations should Narcan/Naloxone NOT be administered?  
In patients with no pulse or infants under 30 days old

78. What are the two common types of Narcan formulations?  
4 mg Narcan nasal spray and 2 mg Naloxone injection

79. How should Narcan/Naloxone be stored?  
Avoid storing in vehicles for long periods and keep away from extreme temperatures

80. What is the standard method for administering Narcan in the field?  
Intranasal (sprayed into the nose)

81. What is the onset time for Narcan/Naloxone?  
3 to 5 minutes

82. What is the peak effect time of Narcan/Naloxone?  
12 to 20 minutes

83. What is the approximate half-life of Narcan/Naloxone?  
45 minutes

84. Which of the following may be evidence of opioid use in an unresponsive patient?  
Bystander report, prescription bottles, patches, track marks, paraphernalia, and toxidrome signs

85. When is it appropriate to administer Narcan/Naloxone?  
During respiratory arrest or hypoventilation (respiratory rate below 8–10 breaths per minute)

86. What are the contraindications for administering Narcan?  
Known hypersensitivity and infants under 30 days old

87. What are common adverse reactions of Narcan?  
Nausea, vomiting, withdrawal symptoms, agitation, irritability, and potential violent behavior

88. Why should caution be used when administering Narcan to opioid-dependent patients?  
It can trigger sudden withdrawal, which may lead to agitation or violent reactions

89. What are the 8 rights of medication administration?  
Right drug, right dose, right documentation, right patient, right time, right route, right response, and right reason

90. How long should you wait after giving the first dose of Narcan before considering a second dose?  
3 to 5 minutes if the patient is still not breathing

91. What components are typically found on a Narcan label or kit?  
Atomizer, Naloxone vial, and needle-free syringe

92. How should used Narcan or Naloxone supplies be discarded?  
Place them in a sharps container located in the back of the ambulance

93. True or False: Every emergency response unit or troop should have a sharps container or biohazard disposal box.  
True

94. What is the primary goal of administering Narcan in an opioid overdose emergency?  
To restore adequate spontaneous breathing

95. True or False: Narcan has no effect if opioids are not present in the system.  
True

96. Why is it important to continue monitoring a patient after Narcan administration?  
Because Narcan may wear off before the opioid does, leading to recurrence of respiratory depression

97. What should you always do immediately after administering Narcan to a patient?  
Call emergency medical services (EMS)

98. Can Narcan be safely used by bystanders with no medical training?  
Yes, it is designed for layperson use and is safe when used as directed

99. Why should Narcan be administered even if you are unsure whether the person used opioids?
Because it has no harmful effects if opioids are not present, and it may save a life

100. How does the short half-life of Narcan impact emergency care decisions?
It requires that patients be continuously monitored and possibly redosed until the opioid wears off

Final Thoughts

Narcan is a simple, safe, and highly effective antidote to opioid-induced respiratory depression, and its timely use prevents hypoxic injury and death.

For respiratory therapists, proficiency with naloxone is more than a medication skill; it is an airway and ventilation safeguard that spans recognition of overdose, rapid administration, assisted ventilation, and vigilant post-reversal monitoring for recurrent depression and withdrawal.

As the opioid crisis persists, respiratory care teams should champion ready access to Narcan, integrate it into protocols, and educate patients, families, and communities on overdose recognition and harm reduction. When deployed promptly and paired with definitive care, Narcan turns a fatal trajectory into a survivable emergency.