Abstract

Context: Low current intensity iontophoresis treatments have shown an increase in skin perfusion over 700% from baseline potentially increasing drug clearance from the targeted area. Objective: To determine the effects of a 10-minute ice massage on subcutaneous dexamethasone sodium phosphate (Dex-P) concentration and skin perfusion during and after a 4 mA iontophoresis treatment. Design: Controlled laboratory study. Setting: Research Laboratory. Patients or Other Participants: 26 individual participants (Males = 15, Females = 11, age = 25.6 Â± 4.5 y, height = 173.9 Â± 8.51 cm, mass = 76.11 Â± 16.84 kg). Interventions: Participants were randomly assigned into two groups: 1) Pretreatment 10-minute ice massage; and 2) no pretreatment ice massage. Treatment consisted of an 80 mA min (4 mAâˆ™20 minutes) Dex-P iontophoresis treatment. Microdialysis probes (3 mm deep in the forearm) were used to assess Dex-P, dexamethasone (Dex), and its metabolite (Dex-met) concentrations. Skin perfusion was measured using laser Doppler flowmetry probes. Main Outcome Measures: Microdialysis samples were collected at baseline, at conclusion of treatment, and every 20 minutes posttreatment for 60 minutes. Samples were analyzed to determine Dex-total concentration ([Dex-total] = Dex-P + Dex + Dex-met). Skin perfusion was calculated as a percent change from baseline. A repeated measures ANOVA was used for Dex-total and Skin Perfusion. Results: No significant difference was found in [Dex-total] between ice and no ice treatments, (P = 0.265). A significant increase in [Dex-total] occurred over the course of the iontophoresis and posttreatment time (P <<> 0.0004). Dex-P was recovered in 15 of 21 participants with a mean concentration of 0.604 Â± 0.843 g/mL. Peak skin perfusion reached 27.74 Â± 47.49% and 117.39 Â± 103.45% from baseline for the ice and nonice groups, respectively. Conclusions: The 10-minute ice massage prior to iontophoresis does not significantly alter the delivery of [Dex-total] through the skin. A greater [Dex-P] was recovered than previously seen with lower intensities.

Degree

College and Department

Life Sciences; Exercise Sciences