J. Alastair Carruthers

Safety of Lidocaine 15% and Prilocaine 5% Topical Ointment Used as Local Anesthesia for Intense Pulsed Light Treatment

BACKGROUND Literature cautions against applying lidocaine 15%/prilocaine 5% over an area larger than 300 cm2. The area of the face, neck, and chest is 400 cm2 or greater. OBJECTIVE To investigate the safety of lidocaine 15%/prilocaine 5% topical anesthetic ointment used as anesthesia for intense pulsed light (IPL) treatment. METHODS AND MATERIALS Lidocaine 15%/prilocaine 5% ointment was applied to the face only (n=10) for 30 ± 15 minutes or to the face, neck, and chest (n=10) for a total of 60 ± 15 minutes before IPL. Blood lidocaine and prilocaine levels were measured. Adverse events were recorded. RESULTS For the entire cohort, blood was drawn 25.6 ± 6.6 minutes after IPL was completed. In the face only group, the mean lidocaine level was 0.122 ± 0.125 μg/mL, and the mean prilocaine level was 0.048 ± 0.029 μg/mL. In the face, neck, and chest group, the mean lidocaine level was 0.272 ± 0.208 μg/mL, and the mean prilocaine level was 0.087 ± 0.060 μg/mL. No adverse events related to systemic toxicity were observed or reported to the nurse. At the 24‐hour follow‐up, no subject reported symptoms of systemic toxicity after leaving the clinic. CONCLUSION Under the conditions of this study, topical lidocaine 15%/prilocaine 5% produces low levels of systemic absorption. The authors have indicated no significant interest with commercial supporters.