A prospective proof of concept study of the efficacy of tacrolimus ointment on uraemic pruritus (UP) in patients on chronic dialysis therapy.

BACKGROUND Uraemic pruritus (UP) is a serious symptom of chronic dialysis patients and patients with end-stage renal disease. UP causes skin damage, discomfort, sleeping disorders and diminished quality of life. Since UP is considered to be in part an immune-mediated inflammatory process, immunosuppressive drugs like tacrolimus may be beneficial. METHODS We conducted a prospective study on the effect of 6 weeks treatment with two sequential concentrations of tacrolimus ointment on the severity of UP in chronic dialysis patients and again after 2 weeks wash-out. Twenty-five patients with UP were enrolled in the study; 21 patients completed the study. UP was measured using a validated modified pruritus assessment score and a Visual Analogue Scale (VAS). RESULTS The modified pruritus assessment score decreased significantly by 81.8% after 6 weeks treatment from [median score 11 (interquartile range: IQR 6-16) on day 0 to median score 2 (IQR 0-5.25) at week 6: P<0.0001]. After 2 weeks wash-out, the median score returned to 72.7% of baseline levels [8 (IQR 2-16)]. Using the VAS score an identical evolution could be demonstrated. Tacrolimus ointment was well tolerated and no serious adverse events were noted. Transient stinging and burning sensation was reported by four patients in the first weeks of the trial, one patient suffered a mild skin rash. No systemic exposure to tacrolimus was detected. CONCLUSION This prospective study has shown that 6 weeks treatment with tacrolimus ointment significantly reduces the severity of UP in chronic dialysis patients and is well tolerated. Randomized placebo-controlled studies are necessary to confirm these encouraging preliminary results.