Introduction: Current regimens of intravenous pamidronate for infants and children with osteogenesis imperfecta (OI) typically deliver 3 to 12mg/kg/yr of drug. We wished to ascertain the effect of pamidronate at 6 or 12mg/kg/yr on skeletal health in OI infants.
Methods: We recruited 12 infants over four years. Infants received either 6 or 12mg/kg/yr of pamidronate. Bone outcomes were assessed by skeletal surveys and DXA bone density measurements at baseline and 12 months.
Results: Bone mass increased in both groups. Infants receiving 12 as opposed to 6mg/kg/yr pamidronate had increased spine bone density after adjusting for co-variates at study entry (p=0.04). Crush fractures improved or remained unchanged in all but one infant. Biochemical markers of bone turnover fell, but remained within or above the normal range for age. Metaphyseal remodelling was not impaired.
Conclusions: Pamidronate dose in infants may influence lumbar spine bone acquisition. Pamidronate improved vertebral size after prior crush fracturing and did not over-suppress bone turnover.
- Osteogenesis imperfecta
- bone densitometry
- vertebral crush fractures