Possible therapeutic use of vasodilator iontophoresis

Background. Investigation into the effects of a novel vasodilator delivery method (for the eventual treatment of scleroderma related digital ulceration) on healthy controls is reported. When Raynaud's phenomenon (episodic cold-induced colour changes of the fingers) occurs in the context of scleroderma, it can be extremely severe, leading to ulceration and sometimes gangrene. The current treatment of choice for scleroderma-related critical digital ischaemia and/or ulceration is intravenous prostanoid therapy, necessitating hospitalisation. However, iloprost is often poorly tolerated and may be ineffective. Methods. This study utilises a newly designed iontophoresis chamber which has the potential to allow a therapeutic, rather than diagnostic application for vasodilatory iontophoresis. Ten healthy controls underwent whole finger iontophoresis with 1% acetylcholine chloride for 2 min at 100 μA. Iontophoresis with varying treatment times and currents was carried out on a subset of subjects to determine the effect on perfusion increase. Results. A significant increase in perfusion following iontophoresis was found, compared to the adjacent, untreated finger (P <0.001). Maximum increase as a percentage from baseline, mean [SD] = 100 [66]%. Both treatment time and current have an approximately linear relationship with perfusion increase. Conclusions. Iontophoresis of the whole finger administers drugs locally with no systemic effects and warrants further investigation as a therapy. © 2005 Elsevier Inc. All rights reserved.