Dexmedetomidine for cancer pain: mechanisms and opioid-sparing effects

Cancer pain treatment faces challenges such as ineffective pain management, high-dose opioid use, and insufficient analgesia. Dexmedetomidine (DEX), a novel α2 receptor agonist, is a potential adjuvant analgesic. Its analgesic mechanism involves central coeruleus cell hyperpolarization, activation of peripheral, spinal cord, and spinal α2 receptors, and regulation of cellular signaling pathways and inflammatory factors. DEX reduces harmful neurotransmitter production and pain signal transmission and enhances opioid analgesia while decreasing opioid use and tolerance. This review introduces the main mechanisms of DEX and its potential for treating complex and refractory cancer pain.

We conducted literature searches using the terms "dexmedetomidine," "cancer pain," "opioid sparing," "analgesic mechanism," and their combinations in PubMed, Embase, Cochrane Library, and Web of Science. We systematically retrieved research articles, reviews, and editorials published in English up to mid-December 2024. All identified publications were reviewed, and their key references were cross-checked to ensure a comprehensive and high-quality review.

Preclinical and clinical studies have demonstrated the advantages and potential of DEX in cancer pain management. DEX has intrinsic analgesic properties and can significantly relieve cancer pain by interacting with opioids, thereby delaying the development of opioid tolerance. It is particularly suitable for patients with refractory cancer pain and provides effective treatment whether used as an analgesic or an anesthetic adjuvant.

DEX is a promising adjuvant for cancer pain management, utilizing multi-mechanism analgesia and opioid-sparing effects to address unmet needs in refractory cases. Preclinical and clinical studies highlight efficacy heterogeneity across different cancer types and limited long-term safety data. High-quality, multicenter randomized controlled trials are needed to determine the optimal dose, refine dosing regimens, and verify results across diverse populations. Until further evidence is available, DEX should be considered a valuable adjunct in individualized, multimodal analgesic strategies, with careful monitoring of hemodynamic parameters and central nervous system adverse events.