ESPE Abstracts

Background: i.v. Pamidronate (PAM) has been used in the treatment of osteogenesis imperfecta (OI) and is known to increase bone mineral density (BMD) and reduce the incidence of fractures. However an attractive alternative is the more potent i.v. Zoledronic acid (ZOL).

Objective and hypotheses: To determine the clinical efficacy of i.v. PAM vs ZOL in children with mild to moderate OI and compare the cost benefits of the two drugs.

Method: A retrospective review of patients aged ≧5 years with type I or i.v. OI, who started either PAM or ZOL (2001–2014) at a tertiary centre was conducted. PAM was administered in cycles of 1.5 mg/kg per day over 2 days every 3 months and ZOL as a single dose of 0.05 mg/kg 6 monthly. Lumbar spine (LS) DXA was performed pre and 1 year post treatment. Cost analysis was performed for a 5 year period based on drug cost, nursing and medical time, equipment and days in hospital per year (8 vs 2 days/year, for PAM vs ZOL).

Results: A total of 40 patients were identified, 20 in each group. LS BMAD z-scores increased significantly in both groups (P<0.001). The median (interquartile range) increase in LS BMAD z-score for the PAM group (1.67 (1.46–2.21)) and the ZOL group (1.75 (1.46–2.00)) was not significantly different. Total cost per treatment cycle per patient was £498 for ZOL and £1157 for PAM. Annual costs for bisphosphonate therapy (BP) per case since the introduction of ZOL halved from £1128 in 2008 to £540 in 2013.

Conclusion: ZOL is a significantly cheaper alternative to PAM with comparable efficacy, resulting in substantial annual savings for health care providers. ZOL is also a more convenient option for patients due to fewer hospital visits, less time off school for patients and leave from work for carers.