Ya slap your dr for being so insensitive to your GERD. Fosamax is not what you need.
You have two good options:
1. Boniva IV push. It's every 3 months which is way better than Fosamax once a month. It's a bit more pricey than Fosamax but it's only 4 times a year. Plus you can have your doc buy it and bill it to your insurance which will be WAY cheaper (and less prior auth hassle) than buying it at the pharmacy. Basically this method accesses your medical benefit as opposed to your pharmacy benefit.
If your doc sucks and refuses to buy and bill Boniva IV, getting it covered by your insurance through your pharmacy benefit (altough more expensive) shouldn't be too difficult because you have GERD. Simply have the doc do a PA for Boniva IV if it's not already covered though your pharmacy benefit and use the GERD scenario to get it covered.
The drawback here is that Boniva doesn't have as great of data as the rest of the bisphosphonates
2. Reclast is an IV drip but it's only once a year. It can cause flu like symptoms and other issues, but aggravating your GERD shouldn't be one of them since it's not PO. Fracture protection data with Reclast is the best of the bisphosphonates (better than Fosamax, Boniva or Actonel) which is rad. And it's billed through your medical benefit so it should be cheaper than fosamax as well
3. You can wait a few months until FDA approval and use a sub cu 2x a year injection of denosumab (Prolia). Same fracture data as Reclast, but it's not IV which is nice. It's injected just like insulin, but of course only 2x a year. And since it's not PO, you don't have to worry about GERD. Fosamax has a 10 year half life, which I think blows. Denosumab's is less than 1/2 a year.
Again, you should push your doc to buy and bill Prolia because it will be a hell of a lot cheaper than going to the pharmacy to get it. And the formulary issues will be almost 0 if you go through your medical benefit versus your pharmacy benefit.
Let me know if you have any questions.