Dose-dependent appearance and disappearance of amiodarone-induced skin pigmentation.

A 66-year-old man suffering from atrial flutter developed cutaneous blue-gray pigmentation while receiving 600 mg of amiodarone daily for 15 months. With reduction of the dose to 100 mg, skin discoloration disappeared within 16 months, to reappear within 7 months after increasing the dose to 400 mg. Finally, the discoloration disappeared within 13 months with a dose reduction to 200 mg daily. It seems that a tissue threshold level for amiodarone exists in this patient, above which skin discoloration appears and below which it fades. Dose, duration, metabolism, macrophage transfer, and spillover saturation-excretion may be relevant in amiodarone-induced skin pigmentation.