Would you avoid the entire class of bisphosphonates if a patient develops an allergic reaction, or would you consider the use of an alternative bisphosphonate?  

Interesting question and an important clinical issue. If the adverse event or side effect was not serious, I would try another bisphosphonate. If it occurred on alendronate, I would try a low dose or risedronate and monitor. If the side effect occurred from the IV infusion, I also would try a low do...

Allergic reactions to biphosphonates are very rare. I have never seen one since those medications started 2 decades ago approximately. I would not use others. I would change to Monoclonal.