Hi Renee,

   Thanks for your question.  There is no truth in the idea that fosamax (alendronate sodium) contains rat poison.  The idea is most likely due to someone confusing fosamax for coumadin.  Coumadin is an anticoagulant used as a blood thinner.  It is often described as rat poison because coumarin derivatives are common ingredients in rat poison.  Fosamax is a safe medication that can be taken once weekly.  The most common side-effects are gastrointestinal related and for this reason the medication should be taken with plenty of water.  Rest assured that it does not contain rat poison however.  For more information on fosamax check out http://www.healthcentral.com/druglibrary/408/fosamax.html 

Thanks

casey