Is it safe for patients with metal implants to have iontophoresis treatment?

BACKGROUND: Iontophoresis passes electrical charge through skin to deliver drugs or reduce excessive sweating. Treatments can be performed by patients at home following initial instruction. A limitation of the technique is that patients are not permitted to have metal implants. These are hypothesized to increase the risk of electric shock, cause localized heating and/or corrosion. OBJECTIVES: To investigate whether metallic materials (titanium, stainless steel and copper) placed in the iontophoresis circuit would lead to an unfavourable outcome regarding corrosion or local heating of the metallic object. METHODS: This was carried out using mass loss and temperature change experiments, together with atomic force microscopy for stainless steel, to assess any surface roughness changes. The investigations were carried out under accelerated conditions (70 V compared with standard use 20-30 V). RESULTS: No changes in mass or clinically significant changes in temperature of any of the metallic objects (or surface roughness for stainless steel) were observed. CONCLUSIONS: This study suggests that patients with these metallic implants can safely undergo iontophoresis treatment. Further work is needed to review the impact on metallic implants with repeated exposure to the iontophoresis system to represent real-world evidence.