Comparison of tetracaine, adrenaline, and cocaine with cocaine alone for topical anesthesia.

A mixture of tetracaine, adrenaline, and cocaine (TAC) has been used extensively in the repair of small lacerations, especially in children. The purpose of this study was to determine whether cocaine alone would provide anesthesia equal to that of TAC, thus eliminating the risk of tetracaine toxicity and the theoretic risk of side effects from the combination of cocaine and adrenaline and simplifying preparation. One hundred thirty-nine patients were enrolled in a randomized, double-blind study comparing TAC with cocaine. Effectiveness was rated by the treating physician. Using the Wilcoxon rank-sum test, TAC was found to provide significantly better anesthesia than cocaine alone (P = .005). The percentage of patients having good anesthesia in the TAC-treated group was approximately 72%, which is equivalent to the efficacy found in other studies. Good anesthesia was obtained in 52% of the cocaine-treated group. No side effects or increased rates of infection were reported in either group.