Experience with Intravenous Zoledronic Acid Treatment for Osteoporosis in the Real Clinical Practice

GONZALEZ D; OLIVERI B,; BAGUR A; MAUTALEN CA

Toronto

Congreso; Meeting of the ASBMR; 2010

ASBMR

Randomized controlled trials have demonstrated that IV Zoledronic acid (ZOL) ensures an effective anti-osteoporotic treatment. In the pivotal trials previous use of IV bisphosphonate was an exclusion criteria and previous oral bisphosphonate was allowed after a long wash out period. However, we cannot apply these measures in the real clinical practice. Aim: to share our experience in the utilization of Zol in osteoporosis during 2007-2010. Methods: patients that had been treated at least with one dose of ZOL were included. We analyzed: a) Changes in serum calcium (sCa), 25OHD, PTH, CrossLaps (CTX), Bone alkaline phosphatase (BAP) 1 to 3 months and 1 year post ZOL. b)Changes in BMD of the lumbar spine (LS), femoral neck (FN) and total femur (TF) one year after ZOL. Results: 71 women of 66.8 + 8.1 years old were included. Only 6 women were naive of bisphosphonate treatment. Four patients presented celiac disease, all of them in effective compliance with their gluten free diet. Fifty eight patients had history of fragility fractures (n=23) and/or BMD T-score < -2.5. Thirteen patients had BMD T-score>-2.5. Biochemical and BMD values at baseline, 1-3 months and 1 year post ZOL are shown in the Table. BMD increased 3.6 % in LS, 2.7% in FN and 2.1% in TF. The increments in LS and FN were significant in both osteopenic and osteoporotic patients. No patient presented hypocalcemia in the post dose control, however sCa levels were significantly lower compared to baseline values. A very significant 73% decrease was observed in the 1-3 months CTX values. CTX levels were at or below the lowest normal limit for premenopausal women in 6 patients. After one year post dose levels were 37% decreased compared to baseline and were still 50% decreased from baseline in 23 out of 50 patients. We found a positive correlation between the % change of CTX 1-3 months post dose and % change BMD TF(r=-0.3; p=0.05) and the % change CTX one year post ZOL and % change BMD FN (r= -0.4; p=0.05). Three patients with previous fractures suffered from a new fracture after ZOL, one of them occurred 1 month after dose. Up-to-day 15 patients received a second ZOL dose. Conclusion: In our experience, IV ZOL has been an effective anti-osteoporotic treatment even in those patients previously treated with oral or IV bisphosphonates. CTX appears  to be an interesting option in monitoring the duration of the IV ZOL effect and could be useful  to decide in certain cases a longer  time for re dosing patients.