We report the results of cyclic intravenous pamidronate therapy for children with osteogenesis imperfecta.

Fourteen patients with mean age 2.7 years were included in this study. Clinical evaluation included: fracture frequency, height gain, activity of daily living, and subjective changes. Bone mineral densitometry, simple radiographic findings, and the change in vertebral height were evaluated. Serum levels of calcium, osteocalcin and the urinary excretion of calcium and N-telopeptide of type I collagen (NTx) were monitored. Histologic study was performed on iliac crest apophysis biopsy samples.

Fracture frequency significantly decreased, from a pre-treatment 0.99 per year per patient to 0.28 per year per patient duringtreatment. Height gain was not affected. Five patients reported subjective improvement. Bone mineral density increased in both lumbar spine and the femur neck. Urinary excretion of NTx and calcium were significantly reduced during each treatment cycle, but were restored at the following cycle. Eleven patients had transient asymptomatic hypocalcemia. A transient febrile reaction was observed in 8 patients during the first cycle, and 4 patients showed a mild increase in the serum transaminase level.

Cyclic intravenous pamidronate treatment is safe and effective for children with osteogenesis imperfecta.