Zoledronic acid： 4 mg or 5 mg？

Zoledronic acid is an aminobisphosphonate that is a potent inhibitor of bone resorption. Now there are two kinds of zoledronic acid（4 mg and 5 mg） on the shelf of the pharmacy with different FDA-approved indications（antihypercalcaemia and anti-osteoporosis）, which makes clinicians and pharmacists confused. Our hypothesis is that 4 mg zoledronic acid could be effective in osteoporosis patients. Theoretically, the mechanism of the anti-osteoporosis effect and anti-hypercalcaemia effect is to inhibit the osteoclasts, thus reducing the serum Ca2＋ concentration and improving the bone mineral density. And the anti-osteoporosis effect of zoledronic acid is dose-dependent. What’s more, some clinical trials showed that 4 mg zoledronic acid was effective in treating osteoporosis. Moreover, several clinical trials have demonstrated that zoledronic acid（4 mg） may be effective in countering bone loss resulted from aromatase inhibitor therapy or endocrine therapy. Thus maybe 4-mg dose is enough for both diseases and the 5-mg dose seems unnecessary. We just need to optimize the dosing frequency according to different conditions.

Zoledronic acid： 4 mg or 5 mg？

zoledronic acid hypercalcaemia osteoporosis