Percutaneous lidocaine administration via a new iontophoresis system in children: tolerability and absence of systemic bioavailability.

OBJECTIVE

Rapid achievement of dermal anesthesia in pediatric practice without discomfort is both desirable and difficult. The Northstar Iontophoretic Drug Delivery System (IDDS) is designed to achieve this objective in 10 minutes using a current of 1.78 mA, compared with the 40 to 60 minutes required for traditional percutaneous methods (eg, eutectic mixture of local anesthetics or EMLA cream). For evaluating the tolerance of this IDDS in pediatrics, 12 healthy children (5-15 years, 4 girls and 8 boys, 10 white, weight 19-79 kg) were evaluated.

METHODS

An open-label trial with random applications of IDDS containing lidocaine (100 mg of 10%) and epinephrine (1.05 mg of 1:10,000) to 3 of the 4 possible sites (back, chest, dorsum of hand, and antecubital fossa) was conducted. Three successive applications (time = 0, 3 hours and 3.5 hours) were performed in each subject, with repeated blood sampling (n = 12 over 10 hours) for assessment of plasma lidocaine concentrations. Skin evaluation (by Draize scoring) at both anode and cathode sites was performed at 10 and 24 hours.

RESULTS

Few of the subjects (0%-28%) experienced any dermal abnormalities at 10 hours. These findings were maintained at the 24-hour follow-up evaluation with the vast majority of subjects (92%-100%) having no evidence of erythema or edema irrespective of application site. Erythema associated with the anode seemed to be more prominent when the study device was applied to either the chest or the back as compared with the antecubital fossa or dorsum of the hand. No subjects complained of pain/discomfort associated with IDDS delivery. Plasma lidocaine levels in all subjects were below 10 ng/mL at all time points.

CONCLUSIONS

The IDDS seems not to deliver a significant, systemic dose of lidocaine and to be well tolerated and potentially suitable for clinical use in pediatric subjects.