Compounded topical anesthetics are often used before certain procedures, including tattooing, laser hair removal, and cosmetic skin treatments. Generally, the Food and Drug Administration (FDA) permits licensed pharmacies to compound commercially unavailable drugs from bulk components for specific prescribed formulations (because of a patient's allergy to an approved product, for example). But compounded topical anesthetics can have grave consequences for health, including seizure and arrhythmia.
The risk is posed by the combination of the local anesthetics lidocaine, tetracaine, benzocaine, and prilocaine
* at often higher concentrations than usual.
* in potentially unsafe combinations.
* packaged with insufficient information for the patient on the product's use and possible adverse effects.
* that are "independently" compounded and therefore not subject to the FDA's review for safety and efficacy.
At the end of 2006, the FDA issued warning letters to five compounding pharmacy firms, advising them to confine their business to the usual practice of compounding topical anesthetic creams. Rather than serving the needs of specific patients for customized products available by prescription only (a practice that is not being questioned), each of the firms had been marketing its compounded formulations essentially "over the counter" to the public as standardized products, in the way that large manufacturers do.
In 2004, at a spa in North Carolina, a college student purchased, without a prescription, two 30-g tubes of an anesthetic gel containing 10% lidocaine, 10% tetracaine, and an unknown amount of phenylephrine in anticipation of a laser hair removal procedure the following day. After applying the gel, the student had a seizure, lapsed into a coma, never regained consciousness, and died eight days later. An autopsy performed one month after the seizure revealed that the victim had succumbed to anoxic injury to the brain attributable to lidocaine toxicity. In 2002 a 23-year-old woman applied a compounded tetracaine and lidocaine product to her legs, which she then covered in cellophane, prior to laser hair removal. She lapsed into a coma and died more than two years later.
Patients should be made aware that the use of any topical medication should be approached with the same caution appropriate to the use of any drug. To avert possible serious complications of the application of any topical anesthetic, nurses should inform patients of the factors that can increase systemic absorption-duration of application, the proportion of total body surface area covered, the use of an occlusive dressing, and characteristics specific to the patient. Susceptible populations include very small children, patients with heart disease, and patients with severe liver disease, who are unable to metabolize local anesthetics. Nurses also should advise outpatients to use only FDA-approved products, to read warnings on product labels, and to consult a provider when necessary. Topical anesthetics serve a useful purpose in health care, but they should be prescribed after a provider has assessed the risks and benefits for the patient.
FDA warns five firms to stop compounding topical anesthetic creams. FDA News 2006 Dec 5. http://www.fda.gov/bbs/topics/news/2006/new01516.html; Young D. Pharmacies warned to stop selling compounded topical anesthetics. Two deaths linked to the products. Health-System Pharmacy News 2006 Dec 11. http://www.ashp.org/s_ashp/article_news.asp?CID=167&DID=2024&id=17784.