Intravenous Lidocaine for the Management of Chronic Pain: A Narrative Review of Randomized Clinical Trials.

Background: Chronic pain remains a serious health problem with significant impact on morbidity and well-being. Available treatments have only resulted in relatively modest efficacy. Thus, novel therapeutic treatments with different mechanisms have recently generated empirical interest. Lidocaine is postulated to provide anti-inflammatory and anti-nociceptive effect through its action at the N-methyl-D-aspartate (NMDA) and voltage gated calcium receptors. Emerging research indicates that lidocaine could be a reasonable alternative for treating chronic pain.

Objective: Considering the evidence surrounding lidocaine's potential as a therapeutic modality for chronic pain, we conducted a narrative review on the evidence of lidocaine's therapeutic effects in chronic pain.

Methods: A review of the PubMed, and Google scholar databases was undertaken in May 2022 to identify completed studies that investigated the effectiveness of lidocaine in the treatment of chronic pain from database inception to June 2022.

Results: A total of 25 studies were included in the narrative review. Findings on available studies suggest that intravenous infusion of lidocaine is an emerging and promising option that may alleviate pain in some clinical populations. Our narrative synthesis showed that evidence for intravenous lidocaine is currently mixed for a variety of chronic pain syndromes. Findings indicate that evidence for efficacy is limited for: CRPS, and cancer pain. However, there is good evidence supporting the efficacy of intravenous lidocaine as augmentation in chronic post-surgical pain.

Conclusion: Lidocaine may be a promising pharmacologic solution for chronic pain. Future investigation is warranted on elucidating the neurobiological mechanisms of lidocaine in attenuating pain signaling pathways.