Chapter 17: Substance Use Disorder

Substance use disorder represents a chronic neurobiological condition involving compulsive engagement with mood- or behavior-altering substances despite significant harmful consequences. This chapter provides comprehensive coverage of the major drug classes implicated in addiction, examining their pharmacological mechanisms, clinical presentations during intoxication and withdrawal, and evidence-based treatment approaches. Opioid abuse, including heroin, fentanyl, oxycodone, and prescription morphine, produces powerful euphoric effects through mu-receptor agonism while carrying substantial risks of respiratory depression, overdose, and fatal complications. Management strategies include naloxone for acute overdose reversal, methadone and buprenorphine for maintenance therapy, and adjunctive medications such as clonidine and naltrexone for relapse prevention. Stimulant substances including cocaine, amphetamines, methamphetamine, and MDMA increase dopaminergic and noradrenergic activity, generating intense euphoria alongside dangerous cardiovascular effects, psychosis, and acute toxicity; withdrawal manifests as depression, hypersomnia, and anhedonia. Depressant drugs encompassing benzodiazepines, barbiturates, and club drugs like flunitrazepam and gamma-hydroxybutyrate produce central nervous system suppression with risks of profound sedation, respiratory failure, and fatal interactions when combined with alcohol; flumazenil serves as a targeted benzodiazepine antagonist. Alcohol use disorder causes acute intoxication and chronic complications including cirrhosis, Wernicke's encephalopathy, Korsakoff's psychosis, and fetal alcohol spectrum disorder, with acute withdrawal potentially progressing to life-threatening delirium tremens managed through benzodiazepines and supportive care; longer-term pharmacotherapy includes disulfiram, naltrexone, and acamprosate. Nicotine dependence develops through stimulation of nicotinic acetylcholine receptors with significant cardiovascular and pulmonary consequences; cessation strategies employ nicotine replacement therapies, bupropion, and varenicline. The chapter emphasizes nursing assessment utilizing standardized screening tools including the CAGE questionnaire and DSM-5 diagnostic criteria, alongside critical nursing responsibilities in withdrawal management, safety monitoring, patient education, and connecting individuals to community-based recovery resources with nonjudgmental, trauma-informed care.