107: Adjunctive Magnesium for Pain Control and Opioid Use in Cancer: A Systematic Review

Topic: Basic Science
Subtopic: Pain category (ICD-11), Acute cancer related pain, , , , , , , , , , Pharmacological interventions, Assessment and Measurement of Pain/Nociception, Drug development

Background and Aims: Cancer-related pain remains a major clinical challenge, often necessitating escalating opioid doses with significant adverse effects. Magnesium, through N-methyl-D-aspartate (NMDA) receptor antagonism and modulation of central sensitization, has been proposed as an adjuvant analgesic capable of enhancing pain control and reducing opioid requirements. This systematic review aimed to evaluate the efficacy of magnesium supplementation, including magnesium sulfate and magnesium L-threonate, as an adjuvant analgesic in adult patients with cancer-related pain, focusing on opioid-sparing effects, pain intensity reduction, and opioid-related adverse outcomes.

Methods: A systematic review was conducted in accordance with PRISMA guidelines. Literature searches were performed in PubMed, Scopus, ScienceDirect, and ProQuest for studies published between 2016 and 2025. Randomized controlled trials and prospective clinical studies evaluating intravenous or oral magnesium in adult cancer patients were included. Outcomes of interest included pain intensity (VAS/NRS), opioid consumption, rescue analgesic use, adverse events, and additional clinical outcomes. Due to substantial heterogeneity, a narrative synthesis was performed.

Results: Five randomized controlled trials involving 390 patients were included. Perioperative intravenous magnesium sulfate demonstrated reduced early postoperative pain scores and decreased rescue analgesic requirements, with an opioid-sparing effect. Magnesium combined with ketamine enhanced acute analgesia but did not prevent chronic neuropathic pain. In chronic cancer-related pain, oral magnesium L-threonate did not significantly reduce pain intensity or persistent pain incidence but was associated with reduced opioid dose escalation and improved opioid-related gastrointestinal side effects. Low-dose oral elemental magnesium showed no additional benefit or mitigating pain intensity in chronic cancer pain.

Conclusions: Magnesium exhibits context-dependent analgesic benefits in cancer-related pain. Intravenous magnesium sulfate appears effective as a perioperative adjuvant, enhancing acute analgesia and reducing opioid requirements while oral magnesium formulations, particularly magnesium L-threonate, may contribute to improved opioid-related outcomes. These findings support the selective use of magnesium as part of a multimodal analgesic strategy in cancer patients, emphasizing tailored application based on pain phenotype and clinical setting.

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Presenting Author: I am, Archie Arman Dwiyatna
Submitting Author: Archie Arman Dwiyatna

Senior Author: Herdiani Sulistyo Putri, MD, FIP.

IASP 2026 Global Year theme of Neuropathic Pain: Yes

• Clara Alverina: MD - Department of Anaesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga, Indonesia - Dr. Soetomo General Academic Hospital, Indonesia
• Herdiani Sulistyo Putri: MD, FIP. - Department of Anaesthesiology and Reanimation, Faculty of Medicine, Universitas Airlangga, Indonesia - Universitas Airlangga Hospital, Indonesia