When deciding to change to a generic there are some things to consider, should one switch brands if....

• they are tolerating one drug without difficulties or adverse reactions?
• it appears that the drug is working (in this case, increased bone density or/and lack of fractures)?
• there is thought to be a difference in drug efficacy?
• the drug being switched to may be less absorbed (i.e within the 20% of the standard FDA's range)?

I think the decision to change to a generic drug must be discussed carefully with your physician and all considerations based on the patient's personal history must be taken into account.

[1] FDA web site: http://www.fda.gov/cder/ogd/

[2] FDA web site: http://www.fda.gov/cder/guidance/5356fnl.pdf