Safety of lidocaine 15% and prilocaine 5% topical ointment used as local anesthesia for intense pulsed light treatment.

BACKGROUND: Literature cautions against applying lidocaine 15%/prilocaine 5% over an area larger than 300 cm(2). The area of the face, neck, and chest is 400 cm(2) or greater. OBJECTIVE: To investigate the safety of lidocaine 15%/prilocaine 5% topical anesthetic ointment used as anesthesia for intense pulsed light (IPL) treatment. METHODS AND MATERIALS: Lidocaine 15%/prilocaine 5% ointment was applied to the face only (n=10) for 30 +/- 15 minutes or to the face, neck, and chest (n=10) for a total of 60 +/- 15 minutes before IPL. Blood lidocaine and prilocaine levels were measured. Adverse events were recorded. RESULTS: For the entire cohort, blood was drawn 25.6 +/- 6.6 minutes after IPL was completed. In the face only group, the mean lidocaine level was 0.122 +/- 0.125 microg/mL, and the mean prilocaine level was 0.048 +/- 0.029 microg/mL. In the face, neck, and chest group, the mean lidocaine level was 0.272 +/- 0.208 microg/mL, and the mean prilocaine level was 0.087 +/- 0.060 microg/mL. No adverse events related to systemic toxicity were observed or reported to the nurse. At the 24-hour follow-up, no subject reported symptoms of systemic toxicity after leaving the clinic. CONCLUSION: Under the conditions of this study, topical lidocaine 15%/prilocaine 5% produces low levels of systemic absorption.

A multicenter, double-blind, randomized, placebo-controlled study of the efficacy and safety of botulinum toxin type A in the treatment of glabellar lines.

BACKGROUND: Botulinum toxin type A (BTX-A) is widely used for facial esthetics but is incompletely studied. OBJECTIVE: This study was conducted to evaluate the efficacy and safety of BTX-A treatment of glabellar lines. METHODS: Patients with moderate to severe glabellar lines at maximum frown received intramuscular injections of 20 U BTX-A (BOTOX, Allergan, Inc, Irvine, Calif) or placebo into 5 glabellar sites. Patients were followed up for 120 days after injection. Outcome measures were physician rating of glabellar line severity at maximum frown and rest, patient assessment of improvement, and vital sign and adverse event monitoring. RESULTS: Two hundred sixty-four patients were enrolled (BTX-A: 203, placebo: 61). There was a significantly greater reduction in glabellar line severity with BTX-A than with placebo (all measures, every follow-up visit; P <.022). The effect was maintained for many patients through day 120. There was a low occurrence (5.4%) of mostly mild blepharoptosis in the BTX-A group. CONCLUSION: BTX-A injections are safe and effective in reducing the severity of glabellar lines.

A novel method to evaluate residence time in humans using a nonpenetrating fluorescent tracer.

PURPOSE: The purpose of these investigations was to develop an improved method for measuring precorneal residence time (RT) and to demonstrate its efficacy with novel formulations. METHODS: A biomicroscope was adapted for use as a clinical fluorometer. Using a nonpenetrating fluorescent probe (FITC-dextran, 70,000-73,000 molecular weight [MW]), RT was estimated as the time to return to baseline (gross RT) and from parameters derived from least-squares regression fits to the decay data (area under the curve [AUC], elimination rate, and time for 50% of the signal to be eliminated [T(50)]). One rabbit and two human studies were conducted. The studies were randomized, double-masked, and controlled. Repeatability in humans was examined in 15 subjects (six determinations per subject, n = 90 total). RESULTS: The FITC-dextran tracer did not penetrate into corneal tissue. The rabbit gross RTs were 14.5, 15.0, and 16.0 minutes for three low-viscosity solutions (eta = 2.7-7.7 mPa/sec) and 22.5 minutes for a more viscous solution (eta = 357 mPa/sec). For a high-viscosity (eta approximately equal 30,000 mPa/sec) gel in humans, the method demonstrated approximately a twofold increase in gross RT and AUC compared with buffered saline. Repeatability of the method appeared acceptable, with intersubject variability the most significant factor affecting precision. CONCLUSIONS: The new method is safe and convenient and offers comprehensive RT data. Furthermore, it appears to differentiate among formulations. However, as with other tear-influenced parameters, there is significant variability. Thus, sufficient sample sizes are necessary for meaningful comparative investigations.