What are good prescription numbing creams for dermatologic Procedures?
Practitioners are increasingly using prescription numbing creams to decrease the pain associated with superficial dermatologic, aesthetic, and laser procedures. Numerous lidocaine-containing products are available, the most popular is lidocaine cream available over the counter. Lidocaine cream is used as tattoo numbing cream. A literature review of currently available for prescription numbing creams, their safety profiles, and dermatologic uses was conducted. Factors that should be considered to reduce the risk of side effects associated with the use of prescription numbing creams include the amount of product used, body location, size of the surface area, and duration of product application. Many case reports document adverse outcomes associated with the use of compounded numbing creams that the Food and Drug Administration has not approved that have inappropriately high anesthetic concentrations and from the use of numbing creams on excessively large skin surface areas during laser treatments. Lidocaine-containing products play an integral role in cutaneous anesthesia by providing patient comfort with minimal side effects. Careful attention must be paid to the particular anatomic location, the total surface area covered, and the duration of anesthetic skin contact.
JOSEPH F. SOBANKO, MD,* CHRISTOPHER J. MILLER, MD,* AND TINA S. ALSTER, MD†
The authors have indicated no significant interest with commercial supporters.
Topical prescription numbing creams decrease pain during cutaneous procedures in the outpatient setting and permit a variety of dermatologic procedures to be performed without anatomic distortion from a local anesthetic injection. As the number of in-office dermatologic procedures continues to grow, practitioners will benefit from awareness of the indications, pharmacologic mechanisms, appropriate methods of application, and safety profiles of the currently available prescription and over-the-counter (OTC) numbing creams.
Historical Background of Prescription Numbing Creams
“Coca” was a term used by the Incas for the substance derived from the plant Erythroxylum coca. The Incas initially reserved the use of coca for their monarch during religious ceremonies. After discovering its anesthetic and stimulatory properties, Peruvians subsequently began to cultivate the plant for commercial distribution. Over time, the plant became a staple of Peruvian culture. Peruvians carried the plant in sidebags called “chuspas” to have it available for chewing. In 1860, Niemann isolated the plant’s active ingredient, cocaine,2 but it was not until 1884 that ophthalmic surgeon Karl Koller demonstrated that general anesthesia could be avoided for ophthalmic procedures by application of cocaine to the conjunctiva.3 Additional ester anesthetics, such as procaine and tetracaine, were created in the early 20th century, but these were noted to result in high rates of allergic contact dermatitis. In 1943, Loefgren synthesized the first amide anesthetic, lidocaine. Subsequently, a large number of topical formulations of esters, amides, and adrenaline have been developed and used for dermatologic procedures. Although the topical formulations are generally safe, allergic reactions, systemic absorption, and death can occur when care is not observed with the use of these products.
Specific FDA-Approved Topical Anesthetics
Topical anesthetics exist in many different preparations and vehicles for delivery. Eutectic mixtures allow individual anesthetic compounds, which are normally in the solid state at room temperature, to be combined as liquids. Eutectic mixtures permit higher concentrations of anesthetic to be used safely and facilitate application to the skin. Liposomal encapsulation is another vehicle that facilitates percutaneous drug delivery. Liposomes are microscopic, spherical, phospho-lipid-based carriers that deliver a greater concentration of local anesthetic to sensory nerves than other conventional formulations with a lower lipophilicity. Improper application of topical anesthetic preparations such as benzocaine cream, lidocaine cream, and tetracaine may cause serious complications, including death. Prolonged application, use of inappropriately high concentrations, and application to large surface areas before outpatient procedures increase the risk of cardiotoxicity and central nervous system toxicity. In general, the central nervous system is more susceptible to the pharmacologic actions of local anesthetics that is the cardiovascular system. The initial symptoms of anesthetic-induced toxicity include lightheadedness, circumoral numbness, diplopia, and tinnitus. (See Table 3 for additional signs and symptoms of lidocaine toxicity.) Many adverse reactions also appear to be related to the inclusion of epinephrine within the anesthetic mixture. In 2006, the FDA warned five pharmacies to discontinue compounding standardized versions of topical anesthetic creams that were already available for general distribution. Concern grew because of the presence of higher concentrations of the compounded anesthetic mixtures than in the FDA-approved products. In addition, the compounded products often lacked appropriate warnings or directions for use. Many of the compounded anesthetics that received a warning from the FDA included products with unknown strengths of active anesthetic and also contained sympathomimetic agents such as phenylephrine, which limits the compounded product’s shelf life because of light sensitivity and increases adverse events related to hypertension and vasoconstriction. Standardization of compounded numbing creams proves difficult because individual pharmacies use different protocols to mix various ingredients in their topical anesthetics.
Despite this FDA warning, a large number of pharmaceutically compounded topical anesthetics remain in use for outpatient procedures such as laser hair removal or soft tissue augmentation (Table 4). Their mechanism of action is similar to that of FDA-approved products, but higher concentrations and various active anesthetics are mixed together. Significant variability in product quality and accurate dosing of these compounded products becomes difficult because they are packaged in widely different containers. Kravitz noted that these compounded numbing creams have a low therapeutic index and are often improperly labeled. All of these factors increase the risk of adverse events, including overdose, seizures, arrhythmias, and death and should prompt practitioners to limit the use of topical anesthetics to those approved by the FDA. The remaining portions of this chapter will focus on prescription numbing creams approved by the FDA for use during outpatient dermatologic procedures.
Clinical Applications of Topical Anesthetics
Topical anesthetics are a versatile supplement to the practice of outpatient dermatologic procedures. Application of prescription numbing creams has proven to decrease pain associated with common procedures such as shave biopsies, punch biopsies, curettage, and electrosurgery. Laser and aesthetic medicine have been strong drivers of the growth of outpatient dermatologic procedures in recent history. Listed below are popular uses of topical anesthetics for aesthetic procedures.
Strongest Topical Anesthetics for Laser and Light-Based Procedures
The most common laser procedure for which numbing creams are used is laser-assisted hair removal, particularly in such sensitive areas as the upper lip and inguinal region.
Best Prescription Numbing Creams for Cosmetic Injectables
Although the application of topical anesthetics is common before injection of dermal fillers, it is generally not necessary for botulinum toxin injection.
Best Numbing Creams for Ablative Laser Skin Resurfacing Treatments
Before the advent of such effective topical anesthetics (alone or in combination), ablative skin resurfacing procedures using carbon dioxide (CO2) and erbium-doped YAG lasers often required the use of intravenous sedation. With the recent introduction of more-superficial ablative procedures and devices (including single-pass CO2 and fractional laser and plasma skin resurfacing), the ability to obtain adequate intraoperative anesthesia with topical application of anesthetics has been achieved.
Best Topical Anesthetic for Chemical Peel
Application of topical anesthetics before chemical peeling has been shown to reduce discomfort without decreasing clinical efficacy of the peel. In a study assessing the use of topical anesthesia for peels, lidocaine was applied without occlusion for 30 minutes after a superficial unbuffered 70% glycolic acid peel and before a medium-depth 35% trichloroacetic acid (TCA) peel.
Tattoo Numbing Cream
Lidocaine-containing products and lidocaine cream play an integral role by providing patient comfort with minimal side effects. Application of topical anesthetic preparations such as benzocaine cream, lidocaine cream, and tetracaine can be used.
Tips for Best Topical Anesthetic Use and Increasing Patient Comfort
No standard guidelines exist for optimal use and safety of all topical anesthetics. Practitioners should read the package inserts of individual products and be completely familiar with their unique characteristics. Suggestions on safe application relate to the size of the anatomic area to be applied, the age and weight of the patient, and the amount (in grams) of anesthetic to be applied. Unfortunately, guidelines do not explicitly stratify the recommended dosage based on the anatomic area to be treated. Absorption of prescription numbing cream will occur more effectively over thin genital mucosal skin than on much thicker acral skin. Product inserts typically recommend the avoidance of application to oral mucosa and to the eyes to prevent severe ocular irritation.
Practitioners are increasingly using topical anesthetics to decrease the pain associated with superficial dermatologic, aesthetic, and laser procedures. Lidocaine-containing products and lidocaine cream play an integral role by providing patient comfort with minimal side effects. Careful attention must be paid to the particular anatomic location, the total surface area covered, and the duration of anesthetic skin contact. Many case reports document adverse outcomes associated with the use of compounded non-FDA-approved products that have inappropriately high anesthetic concentrations and from the use of topical anesthetics on excessively large skin surface areas during laser treatments. Careful selection and application of best topical anesthetic can decrease or eliminate pain during many cutaneous procedures, reduce anatomic distortion by minimizing the volume of intradermal local anesthesia and decrease anxiety in patients who fear pain from procedures.
Topical anesthesia J Anaesthesiol Clin Pharmacol. 2015 Oct-Dec;