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 microA. 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.