Efficacy and safety of zoledronic acid for the treatment of osteoporosis

ABSTRACT

Strength of recommendations: Recommendation strength is weak in favor of using the technology

Technologies: Zoledronic acid

Indication: Osteoporosis treatment

Characterization of the technology: Zoledronic acid belongs to a new class of highly potent bisphosphonate which specifically act on the bone. It is an inhibitor of osteoclastic bone resorption

Question: Zoledronic acid is effective in the osteoporosis treatment?

Search and analysis of scientific evidence: Search and quality of scientific evidence: the databases The Cochrane Library (via Bireme), Medline (via Pubmed), LILACS and Centre for Reviews and Dissemination (CRD) were investigated. We included systematic reviews (SR) and meta-analyzes of clinical trials that assessed the effectiveness of zoledronic acid in the treatment of osteoporosis. Reviews of health technologies (HTS) in agencies of international sites were also selected. The studies showed quality between high and low.

Summary of results of selected studies: Six studies were included: four systematic review (SR) and two publications in Health Technology Assessment (HTS). The results showed that in spite of zoledronic acid have showed beneficial for the outcomes analyzed (bone density, vertebral fracture and nonvertebral), this effect is not statistically different from that reached with other bisphosphonates available by the health care system. Two HTS were included. The first related that no efficacy data from the bisphosphonates use of for longer than five years encompassing outcomes of interest to patients, such as fractures were found. The other reported that zoledronic acid had a similar effect to other bisphosphonates, including presenting a slightly reduced activity in patients who were already taking alendronate previously, a factor assigned to a residual effect of prior bisphosphonate.

Recommendations: The results showed no differences between the zoledronic acid and other bisphosphonates already used as a treatment in clinical practice. The four SR evaluated only one showed a strong statement in support of the technology, this was probably due to the fact that in this study, zoledronic acid was compared to placebo and was regarded the best determinant of patient compliance with treatment. While other studies showed a weak indication for the drug, since the effect on bone mineral density was not statistically different from reached with other drugs. We should make an individualized assessment for each patient on which option is best suited to your needs. Therefore the use of zoledronic acid for the osteoporosis treatment is weakly recommended, since the evidence available so far shows that the drugs available in Brazilian system (SUS) have similar efficacy and lowest cost.

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