A Comparative Study to Evaluate the Efficacy of Topical and Infiltrative Anesthesia for Dermatosurgery Through a Subject-Oriented Approach

Introduction The skin, along with its subcutaneous tissue, constitutes one of the major organ systems of the human body. Dermatosurgery is the branch dealing with skin conditions that operate at the level of skin, without disturbing the milieu intérieur of the human organ system. Materials and methods A cross-sectional study was undertaken, which included 100 patients comprised of 50 patients in each group. For group A, the topical anesthetic agent used was a eutectic mixture of topical 2.5% lignocaine and 2.5% prilocaine cream (EMLA); for group B, infiltration anesthesia with 2% lignocaine injection. Patients satisfying the inclusion and exclusion criteria were recruited for the study. All the participants were requested to rate the pain at the time of drug administration, during the dermatosurgical procedure, and post-procedurally with a visual analogue scale (VAS) separately. Results In this study, 50% of the participants were of the age group of 21-40 years. Males constituted 57.8% whereas females constituted 42.2%. The common procedures performed in the study were electrocautery at 37%, intralesional platelet-rich plasma (PRP) at 16%, and intralesional steroid at 7%. In group A, the VAS score during drug administration was 0. In the group B, 70% had a VAS score of 4-6, and 30% had a VAS score of 1-3 pre-procedurally. The mean VAS score during procedure was 3.06 for group A and 1.03 for group B. Conclusion The study inferred that topical anesthesia is a better choice in superficial dermatosurgical procedures for providing adequate anesthesia and improved compliance when compared to infiltrative anesthesia.

Assessment of clinical efficacy of lidocaine/tetracaine 7%/7% peel cream in fractional microablative laser procedure-associated pain for facial skin aging treatment. A randomized, controlled, single-blind trial

BACKGROUND

Lidocaine/tetracaine 7%/7% peel cream (L/T-pC) is very effective in reducing pain in several dermatological procedures, such as hair or tattoo laser removal or conventional photodynamic therapy associated pain. Fractional laser resurfacing (FLR) is an effective treatment strategy for facial skin aging. The main drawback of FLR is the procedure-associated pain. So far, no controlled data are available regarding the efficacy of L/T-pC in reducing pain during a full-facial microablative FLR session in subjects with facial skin aging.

AIM

To assess the clinical efficacy of L/T-pC in reducing pain during microablative FLR treatment in subjects with facial skin aging. We conducted a prospective, randomized, parallel-group, controlled, single-blind trial, performed in out-patients attending to a Laser Clinic for facial skin aging treatment.

SUBJECTS AND METHODS

A total of 30 subjects (4 men, 26 women; mean age 42 ± 10 years; range 28-57) with mild to moderate facial skin aging (Glogau score ≥2), suitable for FLR treatment, were enrolled after their written informed consent. Participants were randomized to L/T-pC application (45 min before the laser treatment with the removal of the cream just before the starting of laser session) (n = 20) or to control (emollient cream; n = 10). FLR was performing using a fractional microablative CO₂ laser (Smartxide DOT 2 Deka) using a pulse power of 18 W (range 15-20) and pulse duration of 1.5 msec. The primary endpoint was the comparison of the mean visual analogue score (VAS) values between the two groups using a 10-cm scale (0 = no pain; 10: the most severe pain). The VAS score was measured just after the FLR session. Effective anesthesia (percentage of subjects with a VAS score ≤3) and the assessment of local tolerability and safety of the peel cream were the secondary trial endpoints.

RESULTS

All the enrolled subjects concluded the trial. In the L/T-pC group, the VAS mean score was 3.0 ± 1.2. In the control group, the VAS mean score was 8.6 ± 0.5, representing a 65% reduction of the VAS score in the active treated group vs. controls. The difference between the two groups was statistically significant (p = 0.0001; Mann-Whitney test) with an absolute difference of -5 ± 0.4 cm; 95%CI of the difference: from -4.6 to -6.4 cm). Adequate anesthesia (VAS score≤3) was reported in 80% of subjects in the active group vs. 0% in the control arm. The cream was very well tolerated. One subject in the active group manifested moderate/severe edema in the cream application area, subsiding in 6 h. No other side effects were reported.

CONCLUSION

The application of L/T pC 7%/7% peel cream before a fractional laser resurfacing session significantly reduced the procedure-associated pain with good tolerability and safety profile.

Effective use of transdermal drug delivery in children

Transdermal administration offers a non-invasive and convenient method for paediatric drug delivery. The competent skin barrier function in term infants and older children limits both water loss and the percutaneous entry of chemicals including drugs; but the smaller doses required by children eases the attainment of therapeutic concentrations. Transdermal patches used in paediatrics include fentanyl, buprenorphine, clonidine, scopolamine, methylphenidate, oestrogens, nicotine and tulobuterol. Some patches have paediatric labelling supported by clinical trials whereas others are used unlicensed. Innovative drug delivery methods, such as microneedles and sonophoresis are being tested for their safety and efficacy; needleless injectors are primarily used to administer growth hormone; and two iontophoretic devices were approved for paediatrics. In contrast, the immature and rapidly evolving skin barrier function in premature neonates represents a significant formulation challenge. Unfortunately, this population group suffers from an absence of approved transdermal formulations, a shortcoming exacerbated by the significant risk of excessive drug exposure via the incompletely formed skin barrier.

Review of lidocaine/tetracaine cream as a topical anesthetic for dermatologic laser procedures

There are multiple different topical anesthetic options available to minimize the pain associated with cosmetic dermatologic procedures. These options, either alone or in combination, have diverse profiles for effectiveness, ease of use, application time, need for occlusion, and side effects. The lidocaine/tetracaine cream (Pliaglis(®), Galderma Laboratories, Texas, USA), one of the newer combination options, offers effective pain alleviation that has been evaluated in numerous clinical trials. This combination anesthetic is associated with a very favorable profile because of its ease of use and mild side effects compared to other topical local anesthetics. An overview of available topical local anesthetics will be provided with an outline of clinical study characteristics and results regarding the use of lidocaine/tetracaine cream.

Efficacy and safety of a lidocaine/tetracaine medicated patch or peel for dermatologic procedures: a meta-analysis

Background

To justify the use of the lidocaine/tetracaine medicated patch or peel as a preventive treatment for reducing pain and discomfort in adults and children. We reviewed randomized controlled trials (RCTs) to evaluate the efficacy and safety of the lidocaine/tetracaine medicated patch or peel compared with placebo.

Methods

Ten RCTs (574 patients) were included in this systemic review. Relevant studies were identified through searches of MEDLINE, SCOPUS and the Cochrane database library. The outcome was the adequacy of cutaneous anesthesia reflected in the patient's assessment of pain intensity during minor dermatologic procedures and adverse effects after application of the lidocaine/tetracaine medicated patch or peel versus placebo.

Results

The efficacy of the lidocaine/tetracaine patch or peel was consistently very significantly beneficial 30 or 60 minutes after the application compared to placebo (Relative risk, RR: 2.5; Number needed to treat, NNT: 2.2). We did not identify any difference in the effectiveness of adequate analgesia between the lidocaine/tetracaine patch and peel (the number needed to treat or to harm, NNT 2.4 vs. 2.0). No serious side effects or adverse events were observed with the lidocaine/tetracaine medicated patch or peel and placebo. Minor skin reactions were transient and resolved without treatment (Odd ratio, OR: 1.4 and 95% confidence interval, CI: 0.9-2.1; NNT: 14.9).

Conclusions

The lidocaine/tetracaine medicated patch or peel is a well accepted, effective and safe method for minor dermatologic procedures based on pooled data of trials in terms of adequacy of cutaneous anesthesia and adverse effects.

New delivery systems for local anaesthetics-part 2

Part 2 of this paper deals with the techniques for drug delivery of topical and injectable local anaesthetics. The various routes of local anaesthetic delivery (epidural, peripheral, wound catheters, intra-nasal, intra-vesical, intra-articular, intra-osseous) are explored. To enhance transdermal local anaesthetic permeation, additional methods to the use of an eutectic mixture of local anaesthetics and the use of controlled heat can be used. These methods include iontophoresis, electroporation, sonophoresis, and magnetophoresis. The potential clinical uses of topical local anaesthetics are elucidated. Iontophoresis, the active transportation of a drug into the skin using a constant low-voltage direct current is discussed. It is desirable to prolong local anaesthetic blockade by extending its sensory component only. The optimal release and safety of the encapsulated local anaesthetic agents still need to be determined. The use of different delivery systems should provide the clinician with both an extended range and choice in the degree of prolongation of action of each agent.