Objectives: To compare the efficacy of three formulations of a topical anesthetic solution composed of various concentrations of tetracaine hydrochloride, adrenaline (epinephrine), and cocaine hydrochloride (TAC), and to compare the cost of the topical anesthetic solutions with the cost of lidocaine infiltration.
Design: Randomized, double-blind clinical trial.
Setting: Urban pediatric emergency department.
Participants: One hundred fifty-six children 3 to 18 years of age and older requiring topical anesthesia for suturing of lacerations.
Intervention: Children received 3 mL of one of the following study solutions: TAC 1 consisting of 0.5% tetracaine, 1:2000 dilution of adrenaline, 11.8% cocaine; TAC 2 that contained 1% tetracaine, 1:2000 dilution of adrenaline, 4% cocaine; or TAC 3 made up of 1% tetracaine and 4% cocaine, without adrenaline. MEASUREMENTS OR MAIN RESULTS: Patients were randomized to group 1 (n = 49), group 2 (n = 49), or group 3 (n = 58), and received TAC 1, TAC 2, or TAC 3, respectively. Patients in the three study groups were similar for age, gender, anatomic location and length of the laceration, and history of sutures or use of topical anesthesia. Based on the physician assessment of achievement of complete, partial, or no anesthesia, solutions containing 11.8% cocaine (TAC 1) and 4% cocaine with adrenaline (TAC 2) were more likely to produce complete anesthesia than the solution with 4% cocaine without adrenaline (TAC 3) (P < .001, chi 2). This difference was only noted when the laceration involved the face or scalp. A second dose of the TAC 3 solution was more often required to produce anesthesia when compared with the other two study drugs (P < .003, chi 2). The final cost to produce 3 mL of the study drugs, including the vials, was $16.39 for TAC 1, $8.67 for TAC 2, and $8.41 for TAC 3.
Conclusions: The application of a TAC solution containing 4% cocaine is as effective as a TAC solution containing 11.8% cocaine. Use of the 4% solution decreases the cost of the agent. Adrenaline is a necessary ingredient in the anesthetic solution.