A comparison of three formulations of TAC (tetracaine, adrenalin, cocaine) for anesthesia of minor lacerations in children.

A randomized, prospective, double-blind study comparing three formulations of the topical anesthetic solution TAC for laceration repair was undertaken in 250 children. The children's wounds were anesthetized with either TAC I (original formulation--0.5% tetracaine, 1:2000 Adrenalin, 11.8% cocaine), TAC II (1.0% tetracaine, 1:4000 Adrenalin, 7.0% cocaine), or TAC III (1.0% tetracaine, 1:4000 Adrenalin, 4.0% cocaine) prior to repair. The solutions were compared with respect to efficacy, acceptability, wound complications, and side effects. We found comparable efficacy of the three formulations, with similar efficacy to 1% lidocaine infiltration for facial and scalp wounds. Anesthesia for extremity wounds was adequate in only 39.9% of cases, regardless of TAC strength. Wound complications and side effects were within expected and acceptable limits. Our findings support use of TAC for face and scalp lacerations and a change to a less concentrated TAC preparation, such as our "TAC III," which is presumably safer for widespread use.