Local anesthetic effects of Lidocaine cream: randomized controlled trial using a standardized prick pain

Abstract

Background: ELA-max® (4% Lidocaine) and EMLA® cream (Lidocaine–Prilocaine 2.5%) are topicals used for superficial anesthesia. Only few studies have been published on their comparative effectiveness in close-to-practice pain models. Objective: 1) To evaluate the analgesic efficacy of Lidocaine cream compared with Lidocaine–Prilocaine cream and placebo. 2) To assess the safety and tolerability. Methods: Randomized, three-arm, double-blind trial in 40 healthy volunteers comparing the anesthetic effects of Lidocaine and Lidocaine–Prilocaine cream to placebo at various time points (0–120 min). A standardized pain was induced by lancet pricks and measured by a visual analogue scale. Intra-individual comparison between the test areas was performed in a cross-over design. Results: Lidocaine showed significantly reduced pain compared to placebo at all assessment points. Pain reduction was achieved significantly earlier using Lidocaine occlusively (30 min). No significant differences were found concerning the anesthetic efficacy of Lidocaine and Lidocaine–Prilocaine cream. There were no relevant adverse events. Conclusion: This study confirms that a topical preparation with 4% Lidocaine is an effective and safe treatment option for superficial anesthesia. It supports the claim that an occlusive application is more rapid in action. 4% Lidocaine is of value as a rapidly-acting local anesthetic for the treatment of minor surgical procedures.