Overview
Clinical Orientation
Substance use disorder (SUD) is diagnosed from a pattern of impaired control, risky use, and functional or relational harm—not from a positive urine result or from physical depe...
Substance use disorder (SUD) is diagnosed from a pattern of impaired control, risky use, and functional or relational harm—not from a positive urine result or from physical dependence alone. The immediate nursing question is different: is this person intoxicated, withdrawing, injured, infected, suicidal, or at risk of harming someone else? The substance determines the danger. Alcohol withdrawal can progress from tremor and anxiety to seizures or delirium tremens (DTs). Opioid poisoning causes respiratory depression, while opioid withdrawal is intensely uncomfortable but usually not fatal; the major danger follows loss of tolerance and return to use. Benzodiazepines, alcohol, fentanyl, and xylazine may be present together, so persistent sedation after naloxone is not reassurance. Treatment is not a reward for abstinence. For opioid use disorder (OUD), opioid agonist treatment (OAT), overdose prevention, and sterile equipment are parts of the same safety plan. Psychosocial treatment should be offered, but it must not be mandatory before medication. Canadian protocols and nursing authority differ by province; apply the local decision-support tool and stay within the nurse’s regulatory designation.