Hi Hooch, welcome and thanks for your question.  Your Dr. would have to answer this question, since he or she is the only one that knows your medical history, what your t-scores are and if you've had a fracture.

I would ask the Dr. why the Fosamax may not be working, before I'd add another treatment for osteopenia.  Osteopenia is not a disease it's just a pre-cursor to osteoporosis.  That said, you do need to be diligent in preventing osteopenia from progressing to osteoporosis.  Most people have bone loss (osteopenia) and when a drug isn't working they usually look for a secondary cause for this other than normal age-related bone loss.  Here's a list of secondary causes, from the National Osteoporosis Foundation, so you can take this with you to the Dr and discuss it.

Can you ask the Dr. to check for secondary causes of osteoporosis, also reasons why Fosamax may not be working.  I would get these answers since adding a second drug doesn't seem like it would be necessary unless you are at high risk for fracture or you've already had a fracture.  If either of these are the case that may change your treatment plan, but your Dr. would have to make this determination.

Good luck with this and if you have another question just ask.  Thanks for joining us and please return if you need more help.