Oral
bisphosphonates are of proven efficacy in preventing fractures in
postmenopausal osteoporosis. However, poor adherence limits their real-world efficacy and clinical utility.
Zoledronic acid (ZOL) is a potent
bisphosphonate administered by annual
intravenous infusion, effectively ensuring adherence to
therapy over the following year. According to available data, 66% to 79% of patients have expressed a preference for ZOL over oral
bisphosphonates. This is likely to lead to enhanced clinical outcomes, although long-term (repeat annual) adherence is currently unknown. ZOL is of proven efficacy, with hip
fracture reduction of 41% and morphometric vertebral
fracture reduction of 70% over 3 years in the HORIZON PFT trial. It has demonstrated a good side-effect profile with postinfusion flu-like symptoms being the most common. Additionally, it has been associated with decreased mortality in patients following surgery for hip fracture. There is no clear association between exposure and the rate of serious or nonserious
atrial fibrillation. We review adherence to oral
bisphosphonates, and the pharmacokinetics, efficacy, safety, and patient preference for ZOL.