Alcohol use disorder-associated pain: clinical and preclinical evidence

Alcohol Use Disorder (AUD) affects millions of people globally and is characterized by cycles of intoxication, withdrawal, and relapse. Convergent clinical and preclinical evidence strongly support the conclusion that AUD precipitates chronic pain marked by mechanical and thermal hypersensitivity, yet currently available FDA-approved therapeutics do not effectively manage AUD-associated pain. This review synthesizes clinical and preclinical evidence on AUD-associated pain, highlighting known phenomena of allodynia and hyperalgesia as well as small and/or large fiber neuropathy in patient subpopulations along with preclinical acute and chronic alcohol exposure paradigm-specific nociceptive phenotypes in rodents. Herein, we provide detailed descriptions and interpretations of outcome measures for different sensory modalities typically utilized in clinical and/or preclinical studies of nociception. We examine how these endpoints vary in rodent models according to the type of alcohol exposure paradigm with regard to route of administration, chronicity, and contingency (forced, voluntary, or combined). Finally, we summarize the prominent molecular mechanisms that have been proposed to mediate alcohol withdrawal-induced pain-like behaviors. While major advances have been made in treatment of AUD, critical gaps in understanding of human pain phenotypes due to lack of quantitative endpoints in clinical trials impede further advancement in refining preclinical models to recapitulate these features. Patient phenotype-driven preclinical models will increase cross-species translational potential for interrogating mechanistic underpinnings and thereby inform future drug discovery campaigns for treatment of AUD-associated pain.