Chapter 8: Drugs Used in Substance Use Disorder

At the core of the neurobiological theory of addiction is the brain's reward circuit within the limbic system, where misused substances artificially elevate dopamine levels to produce euphoria, eventually leading to permanent neural remodeling, withdrawal symptoms, and increased tolerance. The text breaks down specific categories including alcohol use disorder, which is managed pharmacologically with medications like disulfiram, acamprosate, and naltrexone to restore neurotransmitter balance or discourage consumption through unpleasant physiological reactions. Significant attention is given to the opioid crisis, detailing the life-saving role of naloxone in reversing respiratory depression and the use of methadone and buprenorphine as long-term maintenance strategies. The chapter also addresses the health implications of cannabis and nicotine, highlighting the risks of modern vaping practices—such as e-cigarette or vaping product use-associated lung injury—and the use of smoking cessation aids like varenicline and bupropion. Beyond the biological mechanisms, the material emphasizes the social and individual risk factors, including adolescent brain development, childhood trauma, and the impact of epigenetics on drug-seeking behavior. For nursing professionals, the text provides critical guidance on managing surgical patients at risk for withdrawal and underscores the ethical necessity of providing adequate pain management regardless of a patient's history. Finally, it addresses the sensitive issue of substance misuse within the healthcare workforce, advocating for nondisciplinary rehabilitation programs that prioritize public safety and the recovery of the impaired professional through confidential monitoring and support.