Background Causes of osteoporosis in patients with connective tissue diseases (CTD) are more complex than in patients with postmenopausal osteoporosis (PO). None of the studies published so far examined the safety and efficacy of once-yearly intravenous zoledronic acid 5 mg administration in CTD patients.
Objectives The aim of the study was to assess safety of the zoledronic acid administration in patients with osteoporosis in the course of CTD and compare it to patients with PO.
Methods We investigated 160 patients with osteoporosis including those without CTD or PO who received in total 278 infusions of intravenous zoledronic acid 5 mg in the period 2010-2012. Two subgroups of patients were identified: 47 with osteoporosis in the course of CTD including 33 with rheumatoid arthritis and 91 with PO. All patients included into the study fulfilled the osteoporosis densitometric criteria according to WHO and had contraindications to the use of oral bisphosphonates. The primary endpoint was the number of complications observed in CTD patients after the zoledronic acid administration compared to the number of complications registered in patients with PO.
Results Both PO and CTD patients groups showed no statistically significant differences in terms of the mean age (73 vs. 70,66 years), T score result before the first administration of zoledronic acid (-2,91 vs. -2,81) and mean number of osteoporotic fractures (1,8 vs. 1,69). The number of complications in patients with CTD was significantly higher (14,89% - 7 patients) than in patients with PO (3,29% - 3 patients) (p<0,03). Furthermore in patients with PO the only observed type of adverse reaction were flu-like symptoms whereas in patients with osteoporosis associated with CTD also more severe complications were registered such as the renal function impairment (3 cases) and osteonecrosis of the jaw (1 case).
Conclusions The safety and efficacy of a single 5 mg intravenous infusion of zoledronic acid should be further investigated as our retrospective analysis suggests that in patients with CTD treated with zoledronic acid the number of complications is significantly higher and they are more severe as compared to patients with PO.
Disclosure of Interest None Declared