BACKGROUND

Preparations of 2.5% lidocaine plus 2.5% prilocaine cream (trade name EMLA® cream) or 5% lidocaine cream (trade name LMX5® cream) are used for local anesthesia. To our knowledge, no study has directly compared the analgesic effects for venipuncture between EMLA® cream and LMX5® cream. We conducted a double-blinded randomized crossover trial to evaluate the analgesic effects of these two creams in healthy adults using a visual analogue scale (VAS).

METHODS

This crossover trial enrolled 24 healthy adult participants randomly assigned to 4 groups by combining 2 formulations of anesthetics and different left-right arm-treatment protocols. The primary outcome was each subject’s VAS score (range 0 to 100) for pain during blood sampling. The secondary outcomes were blood sampling site, blood sampling volume, blood sampling frequency, and occurrence of side effects. We conducted a multivariate regression analysis for the VAS score after adjusting for participants’ background characteristics while also adjusting for clustering of arm-treatment protocols within individuals using a generalized estimating equation.

RESULTS

There were no significant differences between EMLA® and LMX5® cream after adjusting for participants’ background characteristics, including age and sex (difference: 2.83; 95% confidence interval: −11.25 to 16.92; P value: 0.693). There were also no marked differences in secondary outcomes between EMLA® cream and LMX5® cream. No adverse reactions that could be clinically problematic were observed with either cream.

CONCLUSION

This randomized crossover trial showed that there was no significant analgesic difference between EMLA® cream and LMX5® cream. Both creams were effective without clinically serious side effects.

The registration number is UMIN000011463.

The registry website is UMIN (http://www.umin.ac.jp/ctr/index.htm).