Efficacy and safety of pamidronate in children with vitamin D intoxication

BackgroundBisphosphonates are used in the treatment of vitamin D intoxication (VDI) after failure of conventional therapy including prednisolone. Safety concerns restrict the use of bisphosphonates from being used as first-line therapy for VDI in children. The aim of this study was to evaluate the efficacy and safety of pamidronate in comparison with prednisolone in children with VDI. MethodsWe reviewed the hospital records of children consecutively diagnosed with VDI at two medical centers in a 15year period. ResultsThe subjects consisted of 21 children (age, 0.3-4.2years) who were treated with prednisolone and/or bisphosphonates. Pamidronate (n=18) or alendronate (n=3) was used in six patients after unsuccessful prednisolone treatment, and in 15 patients from baseline. Initial serum calcium and 25-hydroxyvitamin D were 16.11.9mg/dL and 493 +/- 219ng/mL, respectively. The median time to reach normocalcemia in the pamidronate, alendronate and prednisolone groups was 3days (range, 2-12days), 4days (range, 3-6days) and 17days (range, 12-26days), respectively (P=0.013). The pamidronate group had a fivefold shorter hospital stay than the prednisolone group. Three patients initially treated with prednisolone developed nephrocalcinosis but this did not occur in any patient treated with bisphosphonates from baseline. Apart from transient fever and moderate hypophosphatemia, no side-effect of bisphosphonate treatment was observed. ConclusionsPamidronate is efficient and safe for the treatment of VDI in children. Pamidronate use significantly shortens the duration of treatment, and thereby may prevent the development of nephrocalcinosis. Instead of prednisolone, pamidronate should be used together with hydration and furosemide as the first-line therapy for VDI.