Oral sodium thiosulfate as maintenance therapy for calcific uremic arteriolopathy: a case series.

BACKGROUND: Calcific uremic arteriolopathy (CUA) is a rare but serious disorder affecting 4% of dialysis patients. Intravenous sodium thiosulfate (IV STS) has been shown as an effective treatment. In Canada, the average cost of IV STS is about CAD 12,000 per month, while the cost of compounded oral STS is CAD 45 per month.

METHODS: Prospective cohort where all patients diagnosed with CUA during the year 2011 were included. They were treated initially with IV STS. Afterwards, each patient had a baseline bone scan and was started on oral STS for a total of 6 months followed by a repeat bone scan. A single radiologist, blinded to the dates of both scans for a given patient, read all scans.

RESULTS: Four patients were studied. The intravenous dose used was 25 g three times a week for an average duration of 131 days. After the maintenance therapy, 2 patients developed further regression of the lesions, 1 had stable lesions, and 1 got worse; however, nonadherence to the drug was confirmed. The oral medication was well tolerated with no reported side effects.

CONCLUSION: Oral STS, after IV STS, seems to stabilize, or even improve CUA lesions, and therefore could be useful as maintenance therapy, especially since its cost is much more reasonable than IV STS and due to the ongoing shortage of the IV formulation.