Which bisphosphonate is administered through intravenous injection and can be given yearly or once every two years?

• A. Ibandronate (Boniva)
• B. Zoledronic Acid (Reclast)
• C. Denosumab (Prolia)
• D. Raloxifene (Evista)

Answer: (B)

The correct choice is Zoledronic Acid (Reclast) because it is specifically designed for intravenous administration and is typically given as a single infusion either once a year or once every two years, depending on the patient's medical needs and the specific guidelines for its use in osteoporosis treatment or other indications.

Bisphosphonates like Zoledronic Acid are primarily used to prevent bone loss and reduce the risk of fractures in postmenopausal women and in patients with osteoporosis. The intravenous route of administration allows for effective absorption and can be a convenient option for patients who may have difficulty adhering to daily or weekly oral medication regimens.

Other medications listed are not administered intravenously or do not have a dosing schedule of once yearly or once every two years. For instance, Ibandronate (Boniva) can be given orally or as an injection, but the injection is administered less frequently than annually. Denosumab (Prolia) is also an injectable medication, but it is typically administered every six months. Raloxifene (Evista) is an oral medication and does not have an intravenous form or the same dosing schedule as Zoledronic Acid.