Have Been Taking Boniva Once Monthly For Almost 4 Years,

Have been taking Boniva once monthly for almost 4 years, with improvement the first 2 years. Before that Actonel for several years. Recently had my yearly physical with a bone density scan. Results showed a slight worsening since the last scan two years ago. Physician recommended switching to fosamax, which I am very reluctant to do. Considering one of the once a year injections. What are your thoughts?