Intranasal lidocaine has demonstrated efficacy in decreasing the initial pain and reducing the need for rescue medication among those with acute migraine, according to a study recently published in PLoS One.
This meta-analysis included 6 randomized controlled trials with 613 participants, all of which were located using PubMed, Cochrane Library, EMBASE, and Scopus. The studies included the administration of intranasal lidocaine (treatment) or active comparator/placebo (control) for individuals with migraine. The primary outcome of this meta-analysis was pain intensity, which was quantified via numerical rating, verbal rating, or visual analog scales. Secondary outcomes included the use of rescue medicine, success rate, adverse events, and relapse. The Revised Cochrane risk of bias tool was used to assess study quality. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for dichotomous outcomes, whereas standardized mean differences (SMDs) were used for continuous outcomes.
Compared with controls, individuals given intranasal lidocaine showed lower 5- and 15-minute pain intensity ratings (5-minute SMD -0.61; 95% CI, -1.04 to -0.19; P <.05; 15-minute SMD -0.72; 95% CI, -1.14 to -0.29; P <.05), a lower need for rescue medication (RR 0.51; 95% CI, 0.36-0.72; I² [intervention]=44%), and a 3.55-times higher rate of success (95% CI, 1.89-6.64; I²=31%). In individuals receiving an antiemetic comedication, none of these benefits reached significance. Relapse rate was not significantly improved by intranasal lidocaine (RR 0.89; 95% CI, 0.51-1.56; I²=46%) and did not vary by antiemetic use. One study reported local irritation in ≤49.4% of participants, whereas another reported akathisia in ≤20.4% of those receiving antiemetics.
This study included several limitations, including the tendency of intranasal lidocaine to induce local irritation, thus limiting the degree of blinding; the potential for bias in several studies with participant-reported pain; the inclusion of 2 studies that did not primarily focus on migraine; the use of nonstandardized treatment protocols in certain studies; potential overestimation of the results; and a lack of assessment of publication bias.
The study researchers conclude that in migraine, “the application of intranasal lidocaine can effectively reduce pain intensity,” with benefits including a “decrease in the initial pain by 50% or more,” as well as a reduced need for “rescue medication without increasing the occurrence of relapse and tolerable adverse events.” No add-on effects were observed when intranasal lidocaine was used after participants had “received antiemetics as a treatment for migraines.”
Chi PW, Hsieh KY, Chen KY, et al. Intranasal lidocaine for acute migraine: A meta-analysis of randomized controlled trials [published online October 23, 2019]. PLoS One. doi: 10.1371/journal.pone.0224285