20.3 Substance Use, Addictions, Withdrawal & Harm Reduction

20.3 Substance Use, Addictions, Withdrawal & Harm Reduction

CPCF Appendix A skill #17 requires paramedics to recognize substance use, addictions, mental health and psychiatric conditions in patients, and knowledge #6 names healthy behaviours, disease prevention, harm reduction, quality of life as examinable content. Section 14.4 covers acute toxicology and naloxone pharmacology; this section covers the recognition of substance use disorders, the withdrawal syndromes, and the harm-reduction framework that Canadian paramedicine now operates within.

Substance Use Disorder Is a Health Condition

Substance use disorder is a chronic, relapsing health condition with genetic, neurobiological, developmental, and social contributors. Framing it as a moral failing produces measurably worse care: patients who anticipate judgement delay calling, conceal what they took, and leave before assessment is complete.

CPCF competencies that apply directly:

• F1.2 — practise self-awareness to minimize personal and cognitive bias
• F2.2 — use a trauma-informed approach to care, which matters here because the overlap between substance use and childhood trauma, violence, and homelessness is very high
• F2.3 — adjust and accommodate care to promote equitable health outcomes
• A1.1 — professional behaviours demonstrating compassion and respect

Language is a clinical tool. "A person who uses drugs" rather than "an addict" or "a user"; "substance use disorder" rather than "abuse"; "positive/negative toxicology" rather than "clean/dirty"; "a person with a substance use disorder" rather than "a substance abuser". These are not euphemisms — studies consistently show that clinicians shown identical case details described in stigmatizing language recommend more punitive and less therapeutic management.

The Canadian Toxic Drug Crisis

The unregulated drug supply in Canada is dominated by illicitly manufactured fentanyl and its analogues, now frequently adulterated with benzodiazepines (often called "benzo-dope") and with veterinary sedatives such as xylazine. Three consequences directly change paramedic practice:

1. Potency is unknown and inconsistent. A person cannot titrate a dose they cannot measure.
2. Benzodiazepine adulteration means naloxone may not fully reverse the presentation. The patient may resume breathing but remain deeply sedated, because naloxone has no effect on benzodiazepines. Continue ventilatory support and transport rather than concluding the reversal failed or that opioids were not involved.
3. Xylazine is not an opioid, does not respond to naloxone, and causes prolonged sedation, bradycardia, hypotension, and severe soft-tissue wounds.

Naloxone titration: the goal is restoration of adequate ventilation, not full wakefulness. Give incremental doses and support ventilation between them. Large rapid boluses precipitate acute withdrawal — agitation, vomiting with aspiration risk, and occasionally pulmonary oedema — and destroy the therapeutic relationship with a patient who then leaves before assessment. Renarcotization (Section 18.1) means every reversed patient needs observation and transport.

Withdrawal Syndromes

The examinable principle: opioid withdrawal is miserable but rarely fatal; alcohol and benzodiazepine withdrawal can kill. Candidates routinely have this backwards.

Alcohol withdrawal seizures typically occur 6 to 48 hours after the last drink and may be the presenting event. Delirium tremens peaks at 48 to 96 hours and is a medical emergency with meaningful mortality even with treatment. Benzodiazepines are the definitive treatment; supportive care, thiamine considerations, glucose checking, and transport are the prehospital contribution.

[!IMPORTANT] Never assume that a patient who smells of alcohol is simply intoxicated. People with alcohol use disorder have a high incidence of head injury, hypoglycaemia, gastrointestinal bleeding, infection, seizure, and thiamine deficiency (Wernicke encephalopathy — confusion, ataxia, ophthalmoplegia). The smell of alcohol explains nothing; it is a risk factor, not a diagnosis, and this is the reasoning error that appears most often in inquest findings.

Recognizing Substance Use Without Interrogating

• Ask about all substances routinely and non-judgementally as part of the medication history: prescribed, over the counter, recreational, and natural or herbal (skill #15 names all four categories).
• Normalize the question: "A lot of people use something to get through. Is there anything you're using that I should know about, so I don't give you something that interacts?" The framing makes disclosure useful rather than confessional.
• Physical findings: injection sites and track marks, skin and soft-tissue infections, nasal septal damage, dental erosion, unexplained weight loss, repeated trauma, chronic hepatitis or HIV.
• Contextual findings: paraphernalia, naloxone kits, missed appointments, frequent presentations.
• Do not act shocked or write judgemental descriptions. What you record follows the patient through the health system and shapes how the next clinician approaches them.

Harm Reduction

Harm reduction is explicitly named in CPCF knowledge #6 and is a core part of Canadian public health policy. It aims to reduce the harms associated with substance use without requiring abstinence as a precondition for care.

Good Samaritan drug overdose legislation in Canada provides protection from charges for simple possession, and from some related breaches, for people who call emergency services at an overdose and for those at the scene. Paramedics should be able to explain this accurately, because fear of police is a leading reason people do not call — and a person who knows they will not be charged is a person who calls next time.

Practical harm reduction a PCP can deliver on any call:

1. Ask whether the patient has a naloxone kit and whether they know how to use it.
2. Advise on not using alone, and on the existence of overdose-prevention phone lines and apps.
3. Discuss reduced tolerance after any period of abstinence — after incarceration, hospitalization, or treatment. This is when most fatal overdoses occur and is among the highest-value pieces of information you can give.
4. Provide wound care and refer for infection (Sections 13.6 and 19.3); soft-tissue infection is a major cause of morbidity in this population.
5. Offer, and be able to name, the local referral pathways — withdrawal management, opioid agonist therapy, community health, Indigenous-led services.
6. Treat pain adequately. People who use opioids have high tolerance and real pain, and under-treating it is both a clinical failure and a reason people avoid calling.

When a Patient Declines Transport After an Overdose

This is a high-risk refusal, and it must be managed as a capacity assessment (Section 20.1), not as a formality:

• Assess capacity specifically, recognizing that recent hypoxia and residual sedation impair it, and reassess after time has passed.
• Explain renarcotization plainly: naloxone wears off in roughly 30 to 90 minutes while the opioid may last much longer, and the patient can stop breathing again.
• Explain the specific risk of the adulterated supply, including benzodiazepine sedation that naloxone does not reverse.
• Build a safety net: someone who will stay with them, a naloxone kit in the room, an agreement to call again, a follow-up contact.
• Document thoroughly — the capacity assessment itself, what was explained, what the patient said, and the safety net arranged.
• Leave the door open. How you treat someone at this refusal determines whether they call at all next time.