Antihypertensive Drugs as Potential Repositioning Options for Melanoma: A Map of Pre-Clinical Evidence

Background/Objectives: Melanoma remains one of the most aggressive skin cancers worldwide, with rising incidence and persistent therapeutic challenges, particularly in advanced diseases. Drug repositioning has emerged as a cost- and time-efficient strategy for identifying adjunctive treatments, and antihypertensive medications have attracted attention for their potential off-target antitumor and immunomodulatory effects. This scoping review aimed to map and critically appraise the evidence on the repositioning of antihypertensive drugs for melanoma management. Methods: The review followed the JBI methodology, and the results were reported in accordance with the PRISMA-ScR guidelines. Searches were conducted in July 2025 and updated in May 2026 in PubMed, Scopus, and Web of Science. For Methodological Quality and Risk-of-bias assessment, the SYRCLE Risk of Bias tool was employed for animal studies. Results: This review included 37 studies. β-Blockers, particularly propranolol, were the most frequently investigated agents (n = 21). Several studies reported antiproliferative, pro-apoptotic, antiangiogenic, and immunomodulatory effects; however, these findings were not uniform. Absent direct antiproliferative effects, biphasic dose responses, lack of angiogenic effects, and outcomes dependent on drug concentration, treatment schedule, and experimental model were also reported. Agents targeting the renin-angiotensin system and calcium channels similarly produced heterogeneous and context-dependent findings. The animal studies frequently presented high or unclear risk of bias, particularly because of incomplete reporting of randomization, allocation concealment, and blinding. No formal methodological quality assessment was performed for the in vitro studies. Conclusions: Antihypertensive agents, particularly β-blockers, show promising but heterogeneous preclinical signals in melanoma. However, the available evidence is not sufficient to establish reproducible efficacy or translational validity. Standardized and methodologically rigorous preclinical studies are required before these agents can be considered for clinical investigation as adjunctive melanoma therapies.