Module 8: Harm Reduction – Topic E Provide emergency services and administer naloxone in response to an overdose.

Learning Objectives

By the end of this topic, the student should be able to:

• Describe the mechanism of opioid-induced respiratory depression
• Describe the signs and symptoms of opioid overdose
• Discuss the mechanism of action of naloxone
• Identify the contents of a naloxone kit
• Instruct others on the administration of naloxone
• Stress the importance of calling 911 for all suspected opioid overdoses
• Describe the “Good Samaritan” law in the context of opioid overdose

Key Concepts

• Opioids exert several effects on the body. At high concentrations, opioids disrupt the respiratory centre in the brain, slow breathing, and reduce the sensitivity of the respiratory centre to changes in oxygen and carbon dioxide levels
• A victim of an opioid overdose may have shallow, laboured breathing, or may not be breathing at all, may be unresponsive to verbal or physical stimuli, and will have small, pinpoint pupils
• Naloxone is an opioid receptor antagonist or blocker. When an opioid is over-activating opioid receptors and causing respiratory depression, naloxone will compete with that opioid for receptor binding and “kick off” the opioid from the receptor, to reverse the overdose
• A typical naloxone kit may contain, sterile gloves, two or more doses of naloxone, either an intramuscular form for injection into the arm or leg, or an intranasal form that is sprayed into a nostril. Often an instruction card, alcohol wipes, and a rescue breathing barrier are included
• Naloxone is a short-acting drug and its effects may not last as long as many opioids. It is crucial to call 911 even if naloxone appears to reverse the overdose, because its effects may wear off
• One barrier to calling 911 is a fear of consequences from law enforcement. The Good Samaritan legislation provides protection to those present at the overdose location, should they be in possession of drugs or drug parephenalia
• An opioid overdose is a medical emergency, and regardless of the outcome, administering naloxone, calling 911, providing CPR, or being a bystander to the event may be very stressful and difficult

Opioid-induced Respiratory Depression (OIRD) AKA Opioid Overdose

• Opioids activate opioid receptors, μ, delta, and kappa, κ, throughout the body
• In the respiratory centre (a collection of brain nuclei in the brainstem), μ opioid receptors play a key role in regulating breathing


Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2013). Anatomy and Physiology. OpenStax. https://openstax.org/books/anatomy-and-physiology/pages/1-introduction and licensed under (CC BY 4.0).

• As the concentration of opioids in the brain increases, the function of the respiratory centre is disrupted, reducing its sensitivity to changes in pH, carbon dioxide, and oxygen
• Normally, as breathing slows, carbon dioxide levels rise, and oxygen levels fall, the respiratory centre increases respiration without conscious control
• In the presence of opioids, respiratory centre function is disrupted, and despite a reduction in breathing, the respiratory centre is “turned off” and cannot reverse the respiratory depression
• Breathing continues to become more shallow, less frequent, and may eventually stop
• Factors that increase the risk of an opioid overdose include: the dose of the opioid, the potency of the opioid, the presence of additional CNS depressions (e.g. alcohol, benzodiazepines), pre-existing cardiovascular disease, respiratory disease, obstructive sleep apnea, or any other factor that may impair breathing

Signs and Symptoms of OIRD

Signs and symptoms of OIRD include:

© Course Author(s) and University of Waterloo

Naloxone

Naloxone Kits

Depending on the jurisdiction, naloxone kits can be obtained (free of charge, often without a health card) from pharmacies, public health units, overdose prevention sites and other outreach services.

If a pharmacy doesn’t advertise, offer, or stock naloxone—ASK! One reason that pharmacies may not stock naloxone kits is that they don’t believe their patients and customers are interested in obtaining a kit.

Naloxone Administration

• Intramuscular (IM) naloxone can be injected into a large muscle (shoulder, leg)
• Intranasal naloxone (IN) is sprayed into a nostril
• If there is no effect (no change in breathing, responsiveness) a second dose or additional doses may be administered
• It is not possible to give too much naloxone.
• When an overdose is suspected but not certain, naloxone should be given anyway.
• 9-1-1 should always be called, even if the overdose is successfully reversed with naloxone. The effects of naloxone can wear off more quickly than the effects of many opioids.

How to Administer Intranasal Naloxone:

How to Administer Intramuscular Naloxone:

Good Samaritan Drug Overdose Act of Canada

• Fear of law enforcement can be a barrier to calling 911 in an opioid overdose, particularly if illicit drugs or drug parephenalia are present
• The Good Samaritan Drug Overdose Act protects individuals at the scene of an opioid overdose from charges for possession of a controlled substance, breach of conditions related to drug charges, including pre-trial release, probation orders, conditional sentences, and parole violations
• The Act does not provide protections for outstanding warrants, drug trafficking, or other crimes

After the Overdose

• Participation in an opioid overdose, whether the victim, administering naloxone, calling 911, or being a bystander at the scene, can be very stressful
• In many cases, there is little to no follow-up or ability for individuals to discuss their feelings about being involved
• Anyone feeling anxious or worried after being involved in an overdose/administering naloxone should speak to a health and social service professional or community supports
• For people who have lost a loved one, health and social service professionals and community groups may be a source of information and support. Because of the opioid crisis, support groups specific to persons who have lost loved ones to overdose may be available

Stop and Think

Now that you have reviewed this content, consider the following scenarios:

Questions

Why do opioids cause respiratory depression?

a. They interfere with oxygen/carbon dioxide diffusion in lung tissue

b. They reduce central respiratory centre responsiveness to carbon dioxide

c. They uncouple conscious control of respiratory function

d. They impair oxygen binding to red blood cells

Correct! Opioids act in the respiratory centre to disrupt the brain’s ability to respond to changes in carbon dioxide and oxygen levels.

Incorrect. The correct answer is b. Opioids act in the respiratory centre to disrupt the brain’s ability to respond to changes in carbon dioxide and oxygen levels.

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What is naloxone?

a. An opioid receptor antagonist

b. A stimulant

c. An agent that directly stimulates the lungs, regardless of brain function

d. A high-potency opioid

Correct! Naloxone is an opioid receptor antagonist.

Incorrect. The correct answer is a. Naloxone is an opioid receptor antagonist.

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Naloxone can be administered via all of the following routes, EXCEPT:

a. Intranasal

b. Intramuscular

c. Intravenous

d. Oral administration

Correct! Naloxone cannot be administered orally because it is not absorbed via the GI tract (this is why naloxone does not interfere with buprenorphine when co-administerd orally).

Incorrect. The correct answer is d. Naloxone cannot be administered orally because it is not absorbed via the GI tract (this is why naloxone does not interfere with buprenorphine when co-administerd orally).

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With respect to the Good Samaritan Opioid Overdose Act, which of the following statements is INCORRECT?:

a. The Act applies to individuals who are seeking help during a medical emergency

b. The Act provides legal protection against serious offences such as trafficking of controlled substances

c. The Act protects individuals from charges of possession of controlled substances

d. The Act was created by policy makers as a strategy to support harm reduction

Correct! The act does NOT protect individuals suspected of producing or trafficking controlled substances.

Incorrect. The correct answer is b. The act does NOT protect individuals suspected of producing or trafficking controlled substances.

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References