Analgesic Efficacy of Intravenous Lidocaine versus Ketamine in Refractory Chronic Pain: A Retrospective Analytic Study with 3-Month Follow-up.
Pain medicine (Malden, Mass.) – February 06, 2026
Source: PubMed
Summary
For 120 patients battling refractory chronic pain, a combination of lidocaine and ketamine infusions delivered the most significant immediate relief, reducing pain scores by an average of 3.95 points. Lidocaine infusion alone reduced scores by 3.09, while ketamine infusion lowered them by 2.30. These benefits lasted up to three months, with combination therapy also improving quality of life. Only 7.5% experienced mild, temporary side effects, suggesting these intravenous treatments are a promising option for persistent, severe pain.
Abstract
Refractory chronic pain conditions remain challenging to manage, and intravenous infusions of ketamine, lidocaine, or their combination have emerged as potential therapeutic options. To evaluate the analgesic effectiveness and safety of intravenous lidocaine, ketamine, and their combination in patients with refractory chronic pain. We conducted a retrospective analytic study of patients treated between January 2020 and November 2024 at an outpatient pain clinic. Eligible patients had persistent severe pain (numerical rating scale [NRS] > 6/10) despite ≥ 3 months of multimodal pain management and received intravenous lidocaine, ketamine, or combination infusions. The primary outcome was immediate pain reduction post-infusion. Secondary outcomes included pain relief at 1 and 3 months, quality of life assessed by EQ-5D-5L, and associations between clinical characteristics and treatment response. A total of 120 patients were included. All three groups demonstrated significant reductions in NRS scores from baseline after the first infusion, with mean differences of 3.09 (95% CI 2.56-3.62) for lidocaine, 2.30 (95% CI 1.48-3.13) for ketamine, and 3.95 (95% CI 3.33-4.57) for combination therapy. Analgesic effects persisted at 1- and 3-month follow-up. Mild, self-limiting adverse effects occurred in 7.5% of patients. The combination group showed superior pain reduction at selected time points and greater improvements in quality of life at 3 months. Intravenous lidocaine, ketamine, and combination infusions provide immediate and sustained pain relief in refractory chronic pain. Combination therapy may offer additional benefit beyond monotherapy, supporting its consideration in clinical practice.