The Lidocaine/ Tetracaine Peel: A Novel Topical Anesthetic for Dermatologic Procedures in Adult Patients TINA S. ALSTER, MD

BACKGROUND The 7% lidocaine and 7% tetracaine (LT) peel is a self-occlusive, topical local anesthetic that has been proven safe and effective for use in conjunction with many dermatologic procedures, including cryotherapy, collagen injections, and various laser treatments. The product is applied directly to the skin as a cream that dries within 20 to 30 minutes of air exposure to form a flexible film membrane that is easily peeled off before surgery. OBJECTIVE The objective was to review the safety and efficacy of the LT peel in controlled, randomized trials involving adults undergoing both minor and major dermatologic procedures. METHODS All published studies involving the LT peel were reviewed, and the results of each were analyzed and collated to provide practical guidelines for clinical use. CONCLUSION Studies comparing the LT peel with placebo or a 1:1 eutectic mixture of local anesthetics (EMLA) cream have shown the LT peel to have superior anesthetic efficacy in adult patients undergoing a variety of cutaneous procedures. The LT peel is safe and well tolerated, with side effects limited to localized, transient skin reactions that do not appear to interfere with clinical outcome. It is an effective topical anesthetic for dermatologic procedures that is convenient to use and promotes a positive patient experience. Tina S. Alster, MD, has indicated no significant interest with commercial supporters.

S

everal topical local anesthetics are currently available for use in dermatologic procedures. These agents typically contain lidocaine, to which epinephrine may be added to increase the duration of action and slow the rate of systemic absorption. The most widely used topical agent for anesthetizing intact skin is a eutectic mixture of local anesthetics (EMLA) cream composed of 2.5% lidocaine and 2.5% prilocaine in an oil-in-water emulsion.1 The anesthetic efficacy of EMLA cream has been proven in numerous clinical trials for a variety of cutaneous procedures, including cryotherapy,2 pulsed dye laser (PDL) treatment,3 and debridement of venous leg ulcers.4,5 There are several drawbacks to using EMLA cream, however, including the need for occlusion, inadequate anesthesia at the peripheral skin margins,6 and the potential for eye injury when used in the periocular region.7

The adverse effects of EMLA cream are typically transient and localized.1 The most common adverse effects are edema and erythema or blanching of the skin at the application site. These effects are particularly problematic during such procedures as vascular-specific laser treatment of port-wine stains or vascular lesions, due to their effect on laser energy absorption.6 EMLA cream has also been associated with the development of methemoglobinemia, which is a recognized complication of prilocaine and other local anesthetics. This systemic effect involves the oxidation of iron in red blood cells, which impairs hemoglobin transport of oxygen and is first observed as cyanosis and breathlessness.1 EMLA cream therefore should not be applied in patients with congenital or idiopathic methemoglobinemia and should be used with caution in patients who are taking medications known to exacerbate this disorder, including sulfonamides, acetaminophen,

Washington Institute of Dermatologic Laser Surgery, Washington, DC & 2007 by the American Society for Dermatologic Surgery, Inc.
Published by Blackwell Publishing
ISSN: 1076-0512
Dermatol Surg 2007;33:1073–1081
DOI: 10.1111/j.1524-4725.2007.33221.x 1073

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nitrates, nitrites, and phenobarbitol. Other commercially available topical anesthetics include LMX-4 (formerly ELA-max) and LMX-5, which use liposomes as drug carriers and contain 4% and 5% lidocaine, respectively. Although LMX-5 is marketed for anorectal use, it is often used as a general topical local anesthetic. Compounded combinations available as liquids or gels offer alternative topical local anesthetic options for laceration repair, but they are not appropriate for use on intact skin.8 A combination of 0.5% tetracaine, 0.05% epinephrine, and 11.8% cocaine (TAC) was the first topical anesthetic mixture found to be effective in the treatment of nonmucosal lacerations.9 Concerns regarding toxicity, expense, and regulatory issues associated with the cocaine component have effectively halted the use of TAC, replacing it with the safer and more cost-effective combination of 4% lidocaine, 0.1% epinephrine, and 0.5% tetracaine (LET).8 A combination of 20% benzocaine, 6% lidocaine, and 4% tetracaine (BLT) upon laser stimulus has been shown to provide pain reduction comparable with EMLA cream.10 Because compounded combinations are not subject to the rigorous requirements of the Food and Drug Administration (FDA), only limited safety and efficacy data for these preparations are available. Four deaths related to extensive application of topical BLT for minor outpatient procedures, however, have recently been reported.11 Topical anesthesia can also be enhanced by iontophoresis, which involves the use of electric current to facilitate ionized local anesthetic into and across the skin. Iontophoresis of local anesthetics is limited by the required use of a device, its association with discomfort during the initial period of drug application, its inability to be used over larger surface areas of skin, and its lack of study on the face. Additionally, while rapid, effective anesthesia is produced, the duration of anesthesia is short. To extend anesthetic duration, it is necessary for epinephrine to be added, which is associated with blanching at anodal skin sites.8,12

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Efficacy of the 7% Lidocaine and 7% Tetracaine Peel for Dermal Anesthesia The 7% lidocaine and 7% tetracaine (LT) peel, a 1:1 eutectic mixture of 7% lidocaine and 7% tetracaine, is applied as a cream and air-dries to form a flexible membrane that can be peeled from the skin. Some advantages offered by the new preparation are immediately evident: It is easy to apply and remove (recommended application time is typically 30 min) and, unlike creams or gels, it cannot be rubbed off once it has hardened into a membrane. LT peel does not cause significant swelling, blanching, or reddening at the application site and can be used over large and/or irregular areas of the skin. Other benefits are listed in Table 1. Developed under the name S-Caine peel (ZARS Pharma, Inc., Salt Lake City, UT), the LT peel contains the same mixture of anesthetics as Synera, which is suitable for use on small, flat areas. LT peel has been used successfully and safely for topical local anesthesia in a variety of dermatologic procedures (Tables 2 and 3).

Cryotherapy LT peel was compared with a placebo peel for local anesthesia before cryotherapy treatment in a doubleblind study in 20 adult patients with facial actinic keratoses (Goldberg L, ‘‘A Lidocaine 7% and Tetracaine 7% Peel Is Effective and Safe in Providing Clinically Useful Local Dermal Anesthesia prior to Cryotherapy Treatment in Adults,’’ poster presentation at the American Academy of TABLE 1. Benefits of the LT Peel









Eliminates need for local injection Easy application and removal Unique, no-mess, self-occluding delivery system Conforms to skin topography Anesthetizes large and irregular surface areas Rapid onset of anesthesia (within 20–30 min) Increased vasodilation Excellent safety profile (low systemic exposure/ adverse events)
Extended duration of action may reduce post procedure pain LT, 7% lidocaine and 7% tetracaine.

33 47 36 25 43 59 36 44 54 48

15 17 16 20 9 30 8 22 27 38

94 67 80 53

o.001 o.001 .001

65 75 76 90 78

90

.005

.002 o.001 .017 o.001 o.001

o.001

p Value

27 10 10

43

20 42 54 15 18

37

P

30 5 10

61

25 42 45 15 15

33

P

o.001 o.001 .005

.005

.011 .002 .250 o.001 o.001

o.001

p Value

z

Self-rating by patient, except as otherwise indicated. Fitzpatrick R, Markus R, Alster TS, ‘‘A Lidocaine 7% and Tetracaine 7% Peel Is an Effective And Safe Local Anesthesia prior to Pulsed Dye Laser Therapy to Treat Facial Lesions in Adults,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA. y Goldberg L, ‘‘A Lidocaine 7% and Tetracaine 7% Peel Is Effective and Safe in Providing Clinically Useful Local Dermal Anesthesia prior to Cryotherapy Treatment in Adults,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA. J Alexiades-Armenakas M, Bowers A, Adelglass J, ‘‘A Lidocaine 7% and Tetracaine 7% Peel for Induction of Local Dermal Anesthesia for Collagen Injections on the Face,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA. z Alster TS, Rendon M, Adelglass JA, ‘‘Lidocaine 7% and Tetracaine 7% Peel Is Effective and Safe in Providing Dermal Anesthesia prior to Laser-Assisted Hair Removal in Adults,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA. Alster T, Stewart D, ‘‘A Lidocaine 7% and Tetracaine 7% Peel for Induction of Local Dermal Anesthesia for Non-Ablative Facial Laser Resurfacing,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA. LT, 7% lidocaine and 7% tetracaine peel; P, placebo; PDL, pulsed dye laser.

y

67 80 47

94

o.001 o.001 o.001 .002

65 75 58 90 78

83

LT

Percentage of subjects who would use LT peel again

.007 .002 .034 o.001 o.001

o.001

p Value

LT

P

LT

VAS, Visual Analog Scale; scores range from 0 to 100, with higher scores indicating more pain (0 = no pain, 100 = most pain imaginable).

20-min application PDL for facial vascular lesions (n = 60)z 30-min application Cryotherapy (n = 20)y Collagen injections (n = 52)J Laser-assisted hair removal (n = 50)z Nonablative facial resurfacing (n = 20)14 Nonablative facial resurfacing (n = 40) 60-min application PDL for facial telangiectases/port-wine stain (n = 30)13 Laser leg vein ablation (n = 60)15 Cutaneous laser resurfacing (n = 20)16 Tattoo removal (n = 30)17

Dermatologic procedure

% Subjects with adequate anesthesiay

Median VAS score (mm)

TABLE 2. Summary of Subject Evaluations after Application of the LT Peel and Placebo

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TABLE 3. Summary of Investigator and Independent Observer Evaluations after LT Peel and Placebo

Dermatologic procedure 20-min application PDL for facial vascular lesions (n = 60) 30-min application Laser-assisted hair removal (n = 50) Nonablative laser facial resurfacing (n = 40) Collagen injections (n = 52) Vascular access, adult (n = 55) Vascular access, geriatric (n = 55) 60-min application Laser leg vein ablation (n = 60) Tattoo removal (n = 30)

Investigator rating

Independent observer rating

Percent of patients Percent of patients with with no pain adequate anesthesia

Percent of patients with no pain

LT

P

p Value

LT

P

p Value

LT

P

p Value

63

7

o.001

93

47

o.001

60

17

o.001

44 50

22 10

.018 o.001

82 78

62 22

.033 o.001

44 60

20 10

.027 o.001

46 33 78

19 20 45

o.001 .224 o.001

81 53 80

44 36 45

o.001 .180 o.001

46 35 76

19 24 44

o.001 .356 o.001

48 30

20 7

o.001 o.001

80 70

37 10

o.001 o.001

53 30

12 7

o.001 .002

Data on file. Zars, Inc., Salt Lake City, UT. LT, 7% lidocaine and 7% tetracaine peel; P, placebo; PDL, pulsed dye laser.

Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA). Patients received concurrent 30-minute applications of the LT and placebo, randomized to the top right or bottom left of the treatment surface. After removal of the study drugs, cryotherapy of the actinic keratosis with liquid nitrogen was performed. The study found LT peel to be more effective than placebo in relieving pain, with significantly lower median visual analog scores (VAS) at the LT peel sites than at the placebo sites (17 mm vs. 47 mm; p = .002). The investigator also observed significantly more patients with adequate anesthesia with the LT peel than with placebo (80% vs. 25%; p = 0.005). Three patients had minor, transient, local reactions at the LT peel application site that did not interfere with clinical effect of treatment, but could indicate the need for adequate patient preparation. No clinically significant side effects were encountered.

Dermal Filler Injections LT peel was also found to be significantly more effective than placebo for local anesthesia before

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collagen injections on the face (Alexiades-Armenakas M, Bowers A, Adelglass J, ‘‘A Lidocaine 7% and Tetracaine 7% Peel for Induction of Local Dermal Anesthesia for Collagen Injections on the Face,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA). In a double-blind study, 52 patients received the LT peel and placebo, applied concurrently and randomized to the top right or bottom left matched skin treatment areas. The study drugs were removed after 30 minutes, and collagen injections were administered. Treatment with LT peel produced significantly lower median VAS scores than treatment with placebo (16.0 mm vs. 35.5 mm; po.001. Additionally, significantly more patients reported adequate anesthesia with LT peel than with placebo (75% vs. 42%; p = .002). These results were corroborated by the assessment of pain intensity by the investigator and an independent observer, who rated significantly more patients as having no pain or slight pain with LT peel than with placebo (po0.001). LT peel was well tolerated, with 1 patient experiencing dermatitis at the

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application site that resolved with application of topical corticosteroid cream. There was a higher incidence of slight or well-defined erythema with the LT peel than with the placebo peel (p = .013), but no severe cutaneous reactions were reported.

PDL Therapy Bryan and Alster13 investigated the clinical efficacy of LT peel as a topical local anesthetic before PDL therapy and evaluated the optimal application time in 60 patients with facial telangiectases or port-wine stains.13 LT peel or placebo was applied for 20, 30, or 60 minutes, respectively, in three double-blind, placebo-controlled protocols. After the study drug was removed, laser treatment was administered with a 585- or 595-nm PDL. In all three protocols, patients receiving LT peel experienced significantly greater pain reduction than patients receiving placebo. Patients receiving LT peel for 60 minutes before therapy had a median VAS score of 8.0 mm, compared with a median VAS score of 36.0 mm in patients receiving placebo (p = .005). Application of LT peel for 20 and 30 minutes produced median VAS scores of 15.0 and 8.0 mm, respectively, compared with a score of 54.5 mm for placebo (po.001). The investigators concluded that application of LT peel for 20 or 30 minutes before PDL therapy was as effective in producing anesthesia as pretreatment application for 60 minutes. In all three protocols, side effects were limited to transient, mild erythema. Edema and blanching were not observed. No discernible effect on treatment efficacy was observed despite the vasodilatory effect of the LT peel. Fitzpatrick and coworkers measured the efficacy of LT peel for local anesthesia before PDL therapy in adults with facial vascular lesions (Fitzpatrick R, Markus R, Alster TS, ‘‘A Lidocaine 7% and Tetracaine 7% Peel Is an Effective and Safe Local Anesthesia prior to PDL Therapy to Treat Facial Lesions in Adults,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA).

The double-blind study randomized 60 adult patients to a 20-minute application of either LT peel or placebo before undergoing facial PDL therapy (mean area, 60 cm2 LT peel and 64 cm2 for placebo). The investigators found a significantly lower median VAS pain score with LT peel compared with placebo (15.0 mm vs. 33.0 mm; po.001). Both the patient ratings of pain relief and the investigator ratings of anesthesia control showed LT peel had greater efficacy than placebo. Patients were also significantly more likely to report adequate pain relief with LT peel (90% vs. 37%; po.001), and more patients indicated they would use LT peel again (83% vs. 33%; po.001). Investigator ratings of adequate anesthesia were also significantly greater with LT peel than with placebo (93% vs. 47%; po0.001). Overall, LT peel was well tolerated. One patient experienced tingling of mild severity 5 minutes before LT peel removal, which resolved within 2 hours.

Laser-Assisted Hair Removal Laser-assisted hair removal in adults is another procedure that is rendered more tolerable with application of LT peel. In a double-blind, placebocontrolled study, 50 adults received LT peel and placebo randomized to the top-right or bottom-left side of the treatment surface. The peels were removed after 30 minutes, and the laser-assisted hair removal procedures were performed. Significantly lower median VAS scores were reported with LT peel compared with placebo (19.5 mm vs. 25.0 mm; p = .017; Alster TS, Rendon M, Adelglass JA, ‘‘Lidocaine 7% and Tetracaine 7% Peel Is Effective and Safe in Providing Dermal Anesthesia prior to Laser-Assisted Hair Removal in Adults,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA). Additionally, a significantly greater number of patients reported adequate anesthesia with LT peel than with placebo (76% vs. 54%; p = .034), and more patients reported that they would use LT peel again (80% vs. 52%; p = .006). LT peel was well tolerated in this group

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of patients, and all of the reported adverse events were attributed to the laser procedure rather than to the study drug.

(po.001). Local adverse events (transient erythema, edema, skin discoloration, and contact dermatitis) occurred at similar rates at the LT peel and placebo treatment areas.

Nonablative Facial Laser Resurfacing The efficacy of LT peel for use in nonablative facial laser resurfacing was evaluated by Doshi and colleagues.14 Twenty patients received concurrent 30-minute applications of LT peel and placebo on opposite cheeks. The cheeks were then irradiated with a 1,450-nm diode laser, which is often associated with a more painful cutaneous response than other nonablative lasers. Pain intensity ratings were based on patient-recorded VAS scores. In the areas where LT peel was applied, median VAS scores were substantially lower than at placebo sites (9.0 mm vs. 43.0 mm; po.001). Investigators and an independent observer noted significantly more painless procedures with LT peel (50 and 65%, respectively) than with placebo (0 and 5%, respectively; po.001). Side effects were limited to mild erythema at the LT peel sites. Similar results were found in a second study evaluating LT peel for induction of local dermal anesthesia in patients undergoing nonablative facial laser resurfacing (Alster T, Stewart D, ‘‘A Lidocaine 7% and Tetracaine 7% Peel for Induction of Local Dermal Anesthesia for Non-Ablative Facial Laser Resurfacing,’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA). Before laser irradiation, LT peel was applied to either the right or left side of the facial treatment area, and placebo was applied to the contralateral side in 40 patients for a 30-minute period. Median VAS scores were significantly lower at LT peel sites than at Placebo l sites (30.0 mm vs. 59.0 mm; po.001). Based on patient reports, adequate anesthesia was achieved with LT peel in 78% of patients versus 18% for placebo (po.001). The investigators reported that 93% of patients had no pain or slight pain at the LT peel sites, whereas 58% of patients had no pain or slight pain at the placebo peel sites

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Laser Therapy for Leg Veins LT peel has also been used successfully as a topical anesthetic for more invasive dermatologic procedures that might otherwise be halted due to pain. For such procedures, LT peel is often applied at least 60 minutes before the procedure to ensure adequate pain prevention. Jih and colleagues reported significantly greater pain relief with a 60-minute application of LT peel versus a placebo peel before 1,064-nm long-pulsed Nd:YAG laser treatment of leg veins.15 The longer-wavelength lasers have been associated with a greater degree of pain than conventional lasers and may prompt patients to stop therapy due to pain. The randomized, double-blind, placebo-controlled trial demonstrated significantly lower median VAS scores at the LT peel sites than at the placebo application sites (22.0 mm vs. 44.5 mm; po.001). Sixty-seven percent of patients reported that they would use LT peel again, compared with 30% for the placebo (po.001). No significant differences were found between LT and placebo sites with regard to erythema, edema, or blanching. The results of this study were confirmed by Chen and coworkers6 who used similar methodology: 60-minute application of the LT peel before 1,064-nm long-pulsed Nd:YAG laser irradiation of leg veins.6 Two randomized trials involving 100 patients found that significantly more patients had adequate pain relief at the LT peel application sites than at the placebo application sites. In one of the studies, the median VAS score was 30 mm lower with a 60-minute application of LT peel than with placebo peel (p = .01), and the median VAS score was 27 points lower with a 90-minute application of LT peel than with placebo (po.001). The difference in VAS scores between the two application times was insignificant.

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Cutaneous Laser Resurfacing LT peel was compared with EMLA cream in 20 patients undergoing cutaneous carbon dioxide (CO2) laser skin resurfacing.16 In this double-blind study, LT peel was randomly applied to a 4  4-cm area of one cheek, and EMLA cream was applied under occlusion to the contralateral cheek 30 minutes before laser treatment. Significantly lower median VAS scores were reported for the areas treated with LT peel (27.0 for the LT peel vs. 53.5 for EMLA cream). Adequate pain relief with LT peel was reported by 95% of patients, whereas only 20% of patients had adequate pain relief with EMLA cream. Independent observer and blinded investigator findings were in agreement with the patient ratings. The independent observer noted severe pain in 10% of patients, moderate pain in 65% of patients, mild pain in 20% of patients on the EMLA-treated area, and no pain in 5% of patients. In contrast, moderate pain was observed by the independent observer in 10% of patients, mild pain in 60% of patients, and no pain in 30% of patients in the areas treated with LT peel. Adverse effects of the two topical anesthetics were rated for severity using a 3-point scale (0, none; 1, mild; 2, moderate; 3, severe) and found to be mild overall. On EMLA-treated cheeks, erythema and edema (mean grades, 0.15 and 0.10, respectively) were seen in 10% of patients, and skin blanching was seen in 90% of patients (mean grade, 1.15). On cheeks treated with LT peel, mild erythema was seen in 75% of patients (mean grade, 0.90) and skin blanching in 15% of patients (mean grade, 0.15). One drawback of the study design is the fact that a 30-minute EMLA application time was inadequate for a comparison of its anesthetic effect. Laser-Assisted Tattoo Removal Laser-assisted tattoo removal is another dermatologic procedure associated with a high degree of pain. Chen and coworkers17 studied the anesthetic efficacy of LT peel applied for 60 minutes before laser-assisted tattoo removal.17 The randomized, double-blind study compared LT peel with placebo in 30 adults (mean age, 28 years). The patients re-

ceived concurrent 60-minute applications of LT peel and placebo randomized to the top-right or bottomleft side of the treatment area. After peel removal, laser-assisted tattoo procedures were performed on areas measuring 4 to 6 cm. The investigators found that median patient-reported VAS scores were significantly lower at the LT peel sites than at the placebo sites (38.0 mm vs. 68.0 mm; p = .001). It was further noted that significantly more patients reported adequate pain relief with LT peel than with placebo (53% vs. 10%; p = .002). When asked whether they would use the study drug again, a considerably greater number of patients said they would use LT peel compared with placebo (47% vs. 10%; p = .005). Investigator ratings indicated that significantly more patients received adequate anesthesia with LT peel than with placebo (70% vs. 10%, po.001). Overall, LT peel was well tolerated, with 3 patients experiencing mild-to-moderate erythema or pruritus that resolved spontaneously within 24 hours.

Discussion The benefits of LT peel are listed in Table 1. LT peel provides for a more positive patient experience by reducing the pain and minimizing the anxiety sometimes associated with dermatologic procedures. The need for injectable anesthetics is thus greatly reduced. LT peel’s unique, self-occluding delivery system makes both application and removal simple and eliminates the mess associated with the use of most topical preparations. LT peel can be applied to large areas and is useful on a wide variety of skin surfaces regardless of contour because it conforms to the skin’s topography. Rapid onset of anesthesia (within 20–30 min) provides for patient and provider convenience. LT peel promotes increased vasodilation and has an excellent safety profile with very low systemic exposure and occurrence of adverse events. Clinical efficacy of vascular-specific or other laser treatment does not appear to be influenced by the vasodilatory effect. The additional fact that upwards of 15% of patients may also experience mild skin blanching upon application of LT peel raises the

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issue of decreased clinical efficacy of laser therapy of vascular lesions as has been reported with EMLA use, but this has not been reported to date. The duration of action is sufficient in time to provide continued pain reduction after the procedure. The adverse events related to LT peel are mild in severity and limited to local skin reactions. The most common side effects are transient skin erythema, blanching, and edema. Two studies assessing changes in pharmacokinetics after a single application of LT peel were conducted in adults to evaluate whether adverse events were caused by systemic absorption of tetracaine and lidocaine. In the first study, LT peel was applied for 30, 60, and 90 minutes in areas measuring 50 to 200 cm2. (Ogden L, Love G, Basta S. Systemic Exposure to Lidocaine and Tetracaine is Low after Application of a Lidocaine 7% and Tetracaine 7% (LT) Peel in Adults. Submitted for publication) Concentrations of lidocaine and tetracaine, measured at various time points after LT peel application, were found to be below the lower limit of quantitation values (100 ng/mL for lidocaine and 5 ng/mL for tetracaine). In the second study, LT peel was applied for 30, 60, or 120 minutes to application areas measuring 50 to 400 cm2; plasma samples were obtained at intervals up to 24 hours after application (Copa AK, ‘‘Pharmacokinetics of Lidocaine and Tetracaine Following a Single Application of a Novel LT Peel (Lidocaine 7% and Tetracaine 7% Cream),’’ poster presentation at the American Academy of Dermatology 63rd Annual Meeting; February 18–22, 2005; New Orleans, LA). The maximum plasma concentration of lidocaine was 217 ng/mL, less than 1/20th the lowest concentration considered to be toxic. All tetracaine concentrations were below the lower limit of quantitation value of 0.9 ng/mL. The risk to elderly patients from excessive systemic lidocaine and tetracaine plasma concentrations was similar to, or lower than, the risk to younger adults.

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dures. LT peel is safe with very limited systemic exposure and minimal risk of adverse events. Side effects are generally limited to mild, transient erythema. This convenient new method of topical anesthesia, recently approved by the FDA, has the potential to simplify clinical practice and provide for more positive patient experiences.

Acknowledgments This work was supported by OrthoNeutrogena, Los Angeles, CA. Editorial support was provided by Accel Health, New York, NY.

References 1. Friedman PM, Mafong EA, Friedman ES, Geronemus RG. Topical anesthetics update: EMLA and beyond. Dermatol Surg 2001;27:1019–26. 2. Mansell-Gregory M, Romanowski B. Randomized double blind trial of EMLA for the control of pain related to cryotherapy in the treatment of genital HPV lesions. Sex Transm Infect 1998;74: 274–5. 3. Ashinoff R, Geronemus RG. Effect of the topical anesthetic EMLA on the efficacy of pulsed dye laser treatment of port-wine stains. J Dermatol Surg Oncol 1990;16:1008–11. 4. Holm J, Andren B, Grafford K. Pain control in the surgical debridement of leg ulcers by the use of a topical lidocaineFprilocaine cream, EMLA. Acta Dermatol Venereol 1990;70:132–6. 5. Blanke W, Hallern BV. Sharp wound debridement in local anaesthesia using EMLA cream: 6 years’ experience in 1,084 patients. Eur J Emerg Med 2003;10:229–31. 6. Chen JZ, Alexiades-Armenakas MR, Bernstein LJ, et al. Two randomized, double-blind, placebo-controlled studies evaluating the S-Caine Peel for induction of local anesthesia before longpulsed Nd:YAG laser therapy for leg veins. Dermatol Surg 2003;29:1012–8. 7. Eaglstein NF. Chemical injury to the eye from EMLA cream during erbium laser resurfacing. Dermatol Surg 1999;25:590–1. 8. Kundu S, Achar S. Principles of office anesthesia. Part II. Topical anesthesia. Am Fam Phys 2002;66:99–102. 9. Pryor GJ, Kilpatrick WR, Opp DR. Local anesthesia in minor lacerations: topical TAC vs lidocaine infiltration. Ann Emerg Med 1980;9:568–71. 10. Lee MC. Topical triple-anesthetic gel compared with 3 topical anesthetics. Cosmetic Dermatol 2003;16:35–7. 11. Kapes B. Media microscope analyzes misuse of topicals. Dermatol Times 2005;26:22.

Conclusions

12. Irsfeld S, Klement W, Lipfert P. Dermal anaesthesia: comparison of EMLA cream with iontophoretic local anaesthesia. Br J Anaesth 1993;71:375–8.

LT peel provides rapid anesthesia that has been proven effective for multiple dermatologic proce-

13. Bryan HA, Alster TS. The S-Caine peel: a novel topical anesthetic for cutaneous laser surgery. Dermatol Surg 2002;28:999–1003.

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14. Doshi SN, Friedman PM, Marquez DK, Goldberg LH. Thirtyminute application of the S-Caine peel prior to nonablative laser treatment. Dermatol Surg 2003;29:1008–11. 15. Jih MH, Friedman PM, Sadick N, et al. 60-minute application of S-Caine Peel prior to 1,064 nm long-pulsed Nd:YAG laser treatment of leg veins. Lasers Surg Med 2004; 34:446–50. 16. Alster TS, Lupton JR. Evaluation of a novel topical anesthetic agent for cutaneous laser resurfacing: a randomized comparison study. Dermatol Surg 2002;28:1004–6.

17. Chen JZ, Jacobson LG, Bakus AD, et al. Evaluation of the S-Caine peel for induction of local anesthesia for laser-assisted tattoo removal: randomized double-blind, placebo-controlled, multicenter study. Dermatol Surg 2005;31:281–6.

Address correspondence and reprint requests to: Tina S. Alster, MD, Washington Institute of Dermatologic Laser Surgery, 1430 K Street, NW, Suite 200, Washington, DC 20037, or e-mail: [email protected]

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