Background: Older patients with alcohol use disorder are at particular risk of developing adverse drug reactions due to multimorbidity, polypharmacy, and altered organ function. Objectives: In this study, we investigated the frequency and characteristics of potentially serious alcohol–medication interactions, potentially inappropriate medications (PIMs) for older adults, and potential drug–drug interactions (pDDIs) in a population of older patients with alcohol use disorder over a 10-year period. Design: Retrospective monocentric cohort study. Methods: Prescribed medications were screened for potentially serious alcohol–medication interactions, PIMs, and pDDIs using the POSAMINO (POtentially Serious Alcohol–Medication INteractions in Older adults) criteria, the PRISCUS 2.0 list, the FORTA (Fit fOR The Aged) classification, and the drug interaction program AiD Klinik®. Results: We enrolled 114 patients aged ⩾65 years with alcohol use disorder, who were treated in an addiction unit of a university hospital in Germany. About 80.7% of the study population had at least one potentially serious alcohol–medication interaction. Potentially serious alcohol–medication interactions most commonly affected the cardiovascular (57.7%) and the central nervous system (32.3%). A total of 71.1% of the study population received at least one prescription of a FORTA C or D drug, compared with 42.1% who received at least one PIM prescription according to the PRISCUS 2.0 list. A total of 113 moderate and 72 severe pDDIs were identified in the study population. Conclusion: Older patients with alcohol use disorders are frequently exposed to potentially serious alcohol–medication interactions, PIMs, and pDDIs. Improvements in the quality of prescribing should primarily target the use of cardiovascular and psychotropic drugs.