Treatment of symptomatic osteoporosis in children: a comparison of two pamidronate dosage regimens.

Bisphosphonate treatment for bone fragility has expanded beyond children with osteogenesis imperfecta (OI) to those with other causes of low bone mass. However, clinical efficacy and optimal dosing in non-OI patients has not been established. We conducted a retrospective descriptive study of patients with non-OI-related bone fragility to describe the effects of two different pamidronate treatment regimens on the bone mineral density (BMD) and fracture rate of these children. Between 2000 and 2009, 15 non-OI patients aged 8-16 years received pamidronate 1 mg/kg intravenously for 1 day every 3 months (4 mg/kg/year) or 1 mg/kg/day for 3 days every 4 months (9 mg/kg/year). After 1 year of pamidronate, the two groups had a comparable increase in adjusted BMD and reduction in fragility fractures. No serious adverse effects were observed. Since the long-term effects of bisphosphonate are unknown, large trials are needed to delineate the minimal effective dose in these patients.