Heated lidocaine/tetracaine patch (Synera™, Rapydan™) compared with lidocaine/prilocaine cream (EMLA®) for topical anaesthesia before vascular access

• Published in: British journal of anaesthesia : BJA Vol. 102; no. 2; pp. 210 - 215
• Main Authors: Sawyer, J., Febbraro, S., Masud, S., Ashburn, M.A., Campbell, J.C.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2009; Oxford University Press
• Subjects: Administration, Cutaneous; Adolescent; Adult; anaesthetics local; anaesthetics local, lidocaine; anaesthetics local, prilocaine; anaesthetics local, tetracaine; Anesthesia; Anesthesia, Local - methods; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Anesthetics, Combined - administration & dosage; Anesthetics, Local - administration & dosage; Biological and medical sciences; Double-Blind Method; Drug Combinations; Drug Delivery Systems; Female; Hot Temperature; Humans; lidocaine; Lidocaine - administration & dosage; Male; Medical sciences; Middle Aged; Ointments; pain; Pain - etiology; Pain - prevention & control; Pain Measurement - methods; Phlebotomy - adverse effects; prilocaine; Prilocaine - administration & dosage; tetracaine; Tetracaine - administration & dosage; venepuncture; Young Adult; anaesthetics local, lidocaine; pain; venepuncture; anaesthetics local, tetracaine; anaesthetics local, prilocaine; anaesthetics local; tetracaine; pain; venepuncture; Cream; Anticonvulsant; Prilocaine; lidocaine; anaesthetics local; Antiarrhythmic agent; Local anesthetic; Ester; Local administration; Heat; Pain; prilocaine; anaesthetics local; Anesthesia; Organic amide; Lidocaine; Patch; Tetracaine
• ISSN: 0007-0912; 1471-6771; 1471-6771
• DOI: 10.1093/bja/aen364

We compared the lidocaine/tetracaine patch [Synera™ (USA), Rapydan™ (Europe)], a novel heat-aided patch using a eutectic mixture of lidocaine 70 mg and tetracaine 70 mg, with a eutectic mixture of lidocaine 25 mg ml−1 and prilocaine 25 mg ml−1 (EMLA® Cream). The agents were administered at different time periods for local topical anaesthesia before a vascular access procedure. In this double-blind, paired study, 82 adult volunteers were randomized to receive the lidocaine/tetracaine patch on one anticubital surface and lidocaine/prilocaine cream on the other concurrently for 10, 20, 30, or 60 min before a vascular access procedure. Subjects rated pain intensity using a 100 mm visual analogue scale (VAS). Skin reactions and adverse events were also evaluated. Median VAS scores were significantly lower for the lidocaine/tetracaine patch than for lidocaine/prilocaine cream in the 10 min (P=0.010), 20 min (P=0.042), and 30 min (P=0.001) application groups. The lidocaine/tetracaine patch was associated with significantly more erythema than lidocaine/prilocaine cream at 20, 30, and 60 min, whereas lidocaine/prilocaine cream produced more blanching than the lidocaine/tetracaine patch at 30 and 60 min. Two subjects reported nausea and faintness associated with the vascular access procedure; one was withdrawn from the study. The lidocaine/tetracaine patch provided effective anaesthesia with an application time as short as 10 min and was better than lidocaine/prilocaine cream at all application times shorter than 60 min, demonstrating a substantial improvement in time to onset of anaesthesia. The lidocaine/tetracaine patch provided an important alternative to lidocaine/prilocaine cream for topical local anaesthesia.