Continuous Intravenous Lidocaine for Refractory Cancer Pain in Palliative Care: A Multicenter Feasibility Study

Objectives To assess the feasibility and tolerability of continuous low-dose intravenous lidocaine infusion in patients with opioid-refractory cancer pain receiving palliative care, and to explore its potential impact on pain outcomes in real-world clinical conditions. Methods We conducted a multicenter, randomized, double-blind, placebo-controlled feasibility study in palliative care units to evaluate continuous intravenous lidocaine infusion in patients with opioid-refractory cancer pain. Patients were randomized to receive lidocaine (5 mg/kg/day, increased to 8 mg/kg/day if pain reduction was <30% after 24 h) or placebo for 48 h. Pain intensity was assessed using the Numeric Pain Intensity Scale, with a clinically meaningful response defined as a ≥30% reduction from baseline at 40 min. Secondary outcomes included pain evolution over time, neuropathic pain, symptom burden, and tolerability. Results Thirty-five patients were included in the final analysis (18 lidocaine, 17 placebo). No significant difference was observed between lidocaine and placebo for the primary endpoint or for secondary pain outcomes. Reductions in pain intensity were observed in both groups. In the lidocaine group, 61% of patients required dose escalation to 8 mg/kg/day. Continuous intravenous lidocaine infusion was generally well tolerated, with mostly mild adverse events and no unexpected toxicity. Conclusion In this multicenter feasibility study, continuous low-dose intravenous lidocaine did not demonstrate a clinically meaningful analgesic benefit over placebo. As the planned sample size was not reached, the study was underpowered. These findings highlight the challenges of randomized trials in palliative care and may inform future feasibility-oriented designs.