Title: Lidocaine infusion can be beneficial in a subset of patients with chemotherapy-induced peripheral neuropathy. 

 

Authors: Newaj M. Abdullah, MD, Chaorong Wu, Ph,D, Angela Presson, PhD, Lyen Huang, MD,  Shane E. Brogan, MD

Background & Aims: Chemotherapy-induced peripheral neuropathy (CIPN) is a serious clinical problem in cancer patients undergoing treatment with anti-neoplastic agents. CIPN can manifest as sensory, motor, or autonomic neuropathy. The onset of CIPN can begin within days of chemotherapy treatment and persists for months to years after completion of treatment. The treatment for CIPN is limited to opioids and neuropathic pain medications with variable efficacy. Lidocaine infusion is a treatment modality used for a multitude of difficult-to-treat pain conditions. The mechanism of lidocaine infusion in producing analgesia is not well defined but thought to be mediated by modulation of the sodium ion channel. Lidocaine infusion has been used at the University of Utah for the treatment of CIPN with variable therapeutic response. The objective of this study is to 1) understand the proportion of patients with CIPN who respond to lidocaine infusion, and 2) identify whether treatment with certain chemotherapeutic agents influences treatment response to lidocaine infusion. 

 

Methods: After Institutional Review Board approval, an electronic medical record query was performed to identify patients with CIPN who underwent lidocaine infusion between 2015 and 2022. A chart review was performed on each candidate patient to identify demographics, cancer treatment history, baseline opioid and other neuropathic pain medication use, and therapeutic efficacy from lidocaine infusion. Lidocaine infusion was deemed effective if the patient reported ≥50% pain relief after the first infusion. Descriptive statistics were reported as median with an interquartile variable for continuous variables. Fischer’s exact test was used for categorical variables. An alpha level of 0.05 was selected. R-4.2.2 was used for data analysis.

 

Results: A total of 59 patients underwent lidocaine infusion for CIPN between 2015 and 2022. Table 1 shows demographics, co-morbid neuropathies, and baseline treatment prior to initiation of lidocaine infusion. Table 2 shows lidocaine treatment protocol and outcomes as well as whether treatment with any specific chemotherapeutic agents predicts response to lidocaine infusion therapy. The median amount of lidocaine infused was 500 mg with an interquartile range between 337.5 and 500 mg. Based on the cuff for a response, 64.4% of the patients were responders. The maximum median percent pain relief from lidocaine infusion was 60% for the entire cohort, and among responders, the maximum median percent pain relief was 80%. There is a trend towards patients responding to lidocaine infusion if they were treated with antimetabolites, platinum, and taxane-based chemotherapeutic agents. However, this trend was not statistically significant due to the small sample size and lack of power. 

 

Conclusions: Lidocaine infusion can be an effective adjunct to a subset of cancer patients with CIPN. Future prospective studies are needed to identify if patients with CIPN from a certain group of chemotherapeutic agents are more like to respond to lidocaine infusion.