EFFICACY AND SAFETY OF LIDOCAINE-PRILOCAINE CREAM FOR PAIN DURING CIRCUMCISION

Background Neonatal circumcision is a painful surgical procedure often performed without analgesia, We assessed the efficacy and safety of 5 percent lidocaine-prilocaine cream (Emla) in neonates undergoing circ umcision. Methods We carried out a double-blind, randomized, controlle d trial in 68 full-term male neonates: 38 were assigned to receive lid ocaine-prilocaine cream, and 30 to receive placebo, One gram of lidoca ine-prilocaine or placebo cream was applied to the penis under an occl usive dressing for 60 to 80 minutes before circumcision. Behavioral (f acial activity and time spent crying) and physiologic (heart rate and blood pressure) responses were recorded during the procedure. Blood sa mples were obtained at various times after drug application for measur ements of methemoglobin and plasma lidocaine, prilocaine, and o-toluid ine (a metabolite of prilocaine). Results A total of 68 and 59 neonate s were included in the safety and efficacy analyses, respectively. Dem ographic characteristics such as gestational age and birth weight did not differ between the lidocaine-prilocaine and placebo groups. During circumcision, the neonates in the lidocaine-prilocaine group had less facial activity (P=0.01), spent less time crying (P<0.001), and had s maller increases in heart rate (P=0.007) than the neonates in the plac ebo group, Facial-activity scores were 12 to 49 percent lower during v arious steps of the procedure in the lidocaine-prilocaine group. As co mpared with neonates in the placebo group, infants in the lidocaine-pr ilocaine group cried less than half as much and had heart-rate increas es of 10 beats per minute less. Blood methemoglobin concentrations (ex pressed as a percentage of the hemoglobin concentration) were similar (1.3 percent) in both groups, Lidocaine and prilocaine were detected i n plasma in 23 (61 percent) and 21 (55 percent) of the infants treated with lidocaine-prilocaine cream, respectively. Conclusions Lidocaine- prilocaine cream is efficacious and safe for the prevention of pain fr om circumcision in neonates. (C) 1997, Massachusetts Medical Society.