Cohen S, larkin t, weitzner a, dolomisiewicz e, wang e, hsu a, anderson-white m, smith m, zhao z

There are few efficacious treatments for mechanical neck pain, with controlled trials suggesting efficacy for muscle relaxants and topical non-steroidal anti-inflammatory drugs. Although studies evaluating topical lidocaine for back pain have been disappointing, the more superficial location of the cervical musculature suggests a possible role for topical local anesthetics.

For the primary outcome, the median reduction in average neck pain score was -1.0 (IQR -2.0, 0.0) for the lidocaine phase vs. -0.5 (IQR -2.0,.0) for placebo treatment (p=0.17). 27.7% of patients experienced a positive outcome during lidocaine treatment vs. 14.9% during the placebo phase (p=0.073). There were no significant differences between treatments for secondary outcomes, though a carryover effect on pain pressure threshold was observed for the lidocaine phase (p=0.015). 27.5% of patients in the lidocaine group and 20.5% in the placebo group experienced minor reactions, the most common of which was pruritis (p=0.036).

The differences favoring lidocaine were small and non-significant, but the trend towards superiority of lidocaine suggests more aggressive phenotyping and applying formulations with greater penetrance may provide clinically meaningful benefit.

Steven P. Cohen, Thomas M. Larkin, Aidan S. Weitzner, Edward Dolomisiewicz, Eric J. Wang, Annie Hsu, Mirinda Anderson-White, Marin S. Smith, Zirong Zhao; Multicenter, Randomized, Placebo-controlled Crossover Trial Evaluating Topical Lidocaine for Mechanical Cervical Pain. Anesthesiology 2024; 140:513–523 doi: https://doi.org/10.1097/ALN.0000000000004857