Effect of lidocaine-prilocaine cream (EMLA®) on pain of intramuscular Fluzone® injection

The efficacy of lidocaine-prilocaine cream (EMLA®- Eutectic mixtue 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 < 0.0002) and decreased pain of injection when compaed 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 EMLA®. 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.