Lidocaine 4% cream compared with lidocaine 2.5% and prilocaine 2.5% or dorsal penile block for circumcision

Abstract

This study evaluated the efficacy and safety of lidocaine 4% cream (LMX4), compared with lidocaine 2.5% and prilocaine 2.5% (EMLA) or dorsal penile block (DPNB) for analgesia during circumcision. Healthy, term males (n = 54), younger than 1 week old undergoing circumcision were randomly assigned to open-label pretreatment with LMX4, EMLA, or DPNB. Heart rate (HR; beats per minute [bpm]), respiratory rate (RR; breaths/minute), and arterial oxygen saturation as measured by pulse oximetry (Sp O2; %) were monitored at baseline, and during drug application, circumcision, and recovery. Mean differences were compared using the general linear model. At the end of drug application, mean HR for infants receiving LMX4 (146 bpm; standard error of mean [SEM], 8.0 bpm) was lower than that for DPNB (176 bpm; SEM, 8.3 bpm; p < 0.05). No significant difference in mean HR was observed between treatments during circumcision. Mean RR was higher during circumcision for EMLA compared with LMX4 (p < 0.05) and DPNB (p < 0.05). At lysis, mean RR was significantly lower in DPNB than LMX4 and EMLA. The number of Sp O2 samples was too small for comparison. Three infants (one receiving LMX4 and two receiving EMLA) experienced local reactions (p = 0.54). No adverse effects were observed with DPNB. No difference in analgesic efficacy was observed between treatments according to HR. Differences in RR may reflect a varying level of analgesia. The safety profile was similar for all treatments. LMX4 is an effective analgesic for newborn circumcision.