Which side effect of bisphosphonates is known to present flu-like symptoms?

• A. Risedronate
• B. Zoledronic Acid
• C. Ibandronate
• D. Alendronate

Answer: (B)

Bisphosphonates are a class of medications often used to treat osteoporosis and other bone disorders by inhibiting bone resorption. Zoledronic acid, in particular, is known for its potential to cause flu-like symptoms as a side effect following administration. This occurs due to the medication's effect on the immune system and the inflammatory response it induces in the body.

When a patient receives zoledronic acid, they may experience symptoms such as fever, chills, fatigue, and general malaise, resembling those of an influenza infection. Such side effects are typically most pronounced after the first dose and may not occur with subsequent doses. This phenomenon is largely attributed to the rapid changes in bone metabolism and the body's reaction to the bisphosphonate, which can temporarily stimulate inflammatory cytokines.

In contrast, while other bisphosphonates like risedronate, ibandronate, and alendronate may have their own side effects, they are not commonly associated with the flu-like symptoms in the same way that zoledronic acid is. Therefore, understanding the specific side effects and mechanisms of action of the different bisphosphonates helps to identify why zoledronic acid is the correct answer to this question.