Effect of Lidocaine-Prilocaine Cream (EMLA®) on Pain of Intramuscular Fluzone® Injection

ABSTRACT The efficacy of lidocaine-prilocaine cream (EMLA® — Eutectic mixture of Local Anesthetics) in alleviating the pain of intramuscular injections was investigated in a randomized, double-blind, placebo-controlled, parallel group trial. EMLA® or placebo cream was applied to the arms of 60 adult volunteers before receiving influenza virus vaccine (Fluzone®). Twenty-nine subjects received approximately 2.5 g of EMLA® cream and 31 subjects received approximately 2.5 g of an inert placebo cream under occlusion for 60-90 minutes. The cream was then removed and each subject received one 0.5 mL intramuscular injection of influenza virus vaccine using a 22 gauge one inch needle. Pain of needle puncture and pain of injection were both assessed by the subjects using a visual analog scale. EMLA® was associated with decreased needle puncture pain (p u003c 0.0002) and decreased pain of injection when compared to placebo (p = 0.0139). There was a significant correlation between scores of needle puncture pain and injection pain. Mild skin pallor was a common skin reaction from EMILA®· While the efficacy of EMLA® to alleviate pain of venipuncture is well documented, this is the first study to show the efficacy of EMLA ® for intramuscular injections. RESUME Une etude randomisee a double insu, en controle parallele avec placebo a permis du0027evaluer la capacite de la Lidocaine-Prilocaine (creme EMLA® — melange eutectique du0027anesthesiques locaux) a soulager la douleur causee par les injections intramusculaires. On a applique la creme EMLA® ou un placebo sur le bras de 60 volontaires adultes avant de leur injecter un vaccin viral contre la grippe (Fluzone®). Vingt-neuf (29) sujets ont ete traites avec la creme EMLA® et 31 avec le placebo. Tous ont recu une application du0027environ 2,5 g de creme sous un pansement occlusif pendant 60 a 90 minutes. Apres lu0027elimination de la creme, on leur a injecte 0,5 mL de vaccin par voie intramusculaire au moyen du0027une aiguille calibre 22 du0027un pouce. Les sujets ont evalue la douleur causee par l’insertion de lu0027aiguille et par lu0027injection au moyen du0027une echelle visuelle analogique. Comparativement au placebo, la creme EMLA® a attenue la douleur associee a lu0027insertion de l’aiguille (p u003c 0.0002) et a l’injection (P = 0,0139). On a note une correlation significative entre les cotes se rapportant a la douleur provoquee par lu0027insertion de lu0027aiguille et celles relatives a la douleur causee par lu0027injection. Lu0027apparition du0027une legere pâleur fut une reaction cutanee courante a lu0027application de la creme EMLA®. Il est bien etabli que cette derniere soulage la douleur due a la ponction veineuse, mais la presente etude est la premieree a demontrer son efficacite en cas du0027injection intramusculaire.