Clinical meaning
NP management of substance use disorders requires expertise in medication-assisted treatment (MAT), withdrawal management, and integration of psychosocial interventions. Opioid Use Disorder (OUD): The three FDA-approved medications are buprenorphine, methadone, and naltrexone. Buprenorphine (partial mu-opioid agonist) is the most commonly NP-prescribed MAT: it activates mu-receptors sufficiently to prevent withdrawal and craving but has a 'ceiling effect' that limits respiratory depression risk. The X-waiver requirement was ELIMINATED in 2023 — all DEA-licensed prescribers can now prescribe buprenorphine for OUD. Buprenorphine/naloxone (Suboxone) is the standard formulation; naloxone is added to deter IV misuse (naloxone is poorly bioavailable sublingually but precipitates withdrawal if injected). Induction timing is critical: buprenorphine must not be started until the patient is in MODERATE withdrawal (COWS score ≥8-12) — starting too early precipitates withdrawal because buprenorphine displaces full agonists from receptors while providing only partial activation. Methadone (full mu-agonist) can only be dispensed through federally licensed opioid treatment programs (OTPs) — NPs cannot prescribe methadone for OUD in office-based settings. Alcohol Use Disorder (AUD): Naltrexone (opioid antagonist) 50 mg PO daily or 380 mg IM monthly reduces heavy drinking days; acamprosate 666 mg TID modulates glutamate/GABA balance to reduce craving; disulfiram 250 mg daily causes aversive reaction with alcohol (acetaldehyde accumulation). Tobacco: Varenicline (partial nicotinic agonist) is the most effective single pharmacotherapy — reduces craving and withdrawal while blocking nicotine's rewarding effects.