Abstract
Osteoporosis affects over 350,000 New Zealanders including 30% of women aged over 60 years and more than half aged over 80. Osteoporotic fractures are a significant cause of morbidity and mortality. From July 1999 to 30 June 2000, 3131 people aged over 65 sustained a fractured neck of femur. 27% died in the subsequent 12 months, equating to 17% of all cause mortality. Fractures are also a significant economic burden. In the period, July 2005 to June 2006, over $18 million was spent on hip fractures in those aged over 65 years. Bisphosphonates improve Bone Mineral Density and consequently reduce the incidence of fracture; however oral bisphosphonates are contraindicated in some patients. Zoledronate is an intravenous bisphosphonate that has recently been licensed for osteoporosis treatment.
We undertook a retrospective chart review and General Practitioner consultation of CMDHB patients who received zoledronate from June 2006 to June 2008. Assessment of clinician compliance with current safety protocols, patient outcomes and side effects were assessed. 78 patients received 101 doses of zoledronate, approximately double the preceding 2 year period (37 patients and 60 administrations). The most commonly indication was osteoporosis. 19% (19/101) administrations were organised through the geriatric clinic and 81% (82/101) were inpatients
Bone Mineral Densities within 2 years were available for 59% (48/82) of administrations. 80% (51/64) had previous osteoporotic fractures. 84% (54/64) of osteoporotic patients were utilising additional calcium and vitamin D therapy. Oral bisphosphonates were contraindicated in 94% (60/64) because of gastrointestinal upset, 3% (2/64) for headaches and 3% (2/64) for worsened BMD despite oral bisphosphonates. Following treatment 13% (8/64) of patients sustained further fractures. In inpatient administration 83% (21/82) pre-creatinine and 80% (66/82) post-creatinine measurements were appropriately assessed in comparison to 58% (11/19) and 79% (15/19) respectively for clinic patients. In inpatients administration 59% (48/82) pre-calcium and 63% (52/82) post-calcium measurements were appropriately assessed in comparison to 37% (7/19) and 68% (13/19) respectively for clinic patients. For GP follow-up of creatinine and calcium measurements, 90% had creatinine and 80% had calcium correctly assessed. Zoledronate was well tolerated with no jaw osteonecrosis in this cohort.
Zoledronate is a well tolerated treatment for osteoporosis in those patients intolerant of oral bisphosphonates. The use of zoledronate has more than doubled in the last 2 years. Stricter adherence to current guidelines is needed to prevent incipient adverse effects.
Correspondence should be addressed to: Associate Professor N. Susan Stott, Orthopaedic Department, Starship Children’s Hospital, Private Bag 92024, Auckland, New Zealand.
