Use of tetracaine, epinephrine, and cocaine as a topical anesthetic in the emergency department.

The combination of tetracaine, epinephrine, and cocaine has gained wide acceptance as a topical anesthetic agent for use on pediatric dermal lacerations in the ED. This is despite the fact that the optimal dose and formulation have yet to be determined. TAC can be applied painlessly to wounds and is about as effective as lidocaine infiltration for anesthetizing pediatric facial and scalp lacerations. It is relatively ineffective on lacerations located elsewhere or in adults. The most commonly used TAC solution contains high concentrations of cocaine, tetracaine, and epinephrine, drugs that individually can cause serious toxicity if absorbed in sufficient amounts. In addition, the three components of TAC may interact to potentiate their intrinsic toxicities. The deliberate and inadvertent application of TAC to mucous membranes has caused status epilepticus and two pediatric deaths. The risk of toxicity from misapplication of TAC is heightened because TAC is most effective and therefore most widely used on pediatric facial and scalp lacerations. Cocaine is also absorbed after TAC is applied to dermal lacerations and may cause toxicity by this route. Until additional research is performed to establish the minimum effective dose of TAC and its potential toxicity and until FDA approval is granted, we do not think that it can be recommended as the drug of choice for pediatric facial and scalp lacerations in the ED. If TAC is administered, a maximum dose of 2 to 3 mL of the "half-strength" formula proposed by Bonadio and Wagner should be used, and application should be performed by medical personnel, using a soaked gauze or cotton ball. Care should be taken to make sure none of the solution comes in contact with mucous membranes, and TAC should not be applied to lacerations involving the vermillion border of the lip or the lip itself. Close medical monitoring of the patient is essential to detect signs of toxicity. Research on other topical agents such as tetracaine with epinephrine is also needed. Although anesthetizing wounds painlessly remains a worthy goal, exposing patients to added and unknown risks and increasing the cost of health care is unacceptable.