Is there a way to find out how long medicine is "good" for (Prometrium, specifically)?

[DomerJen]

I know that many meds are fine past their "expiration" date, but is there a way to find out?  I have some prometrium from my last pregnancy (exp 8/09) and I need to refill my current prescription, but I'd like the doc to change it a bit so that I get more for my $.  SHe's out of the office and to refill my current prescription for 5 days is $35.  I'd love to use the old stuff if it'd be ok while I wait for her to change it on Monday.

Anyone have info on this?

[bcblondie]

I saw a news clip the other day that the army (since they have to store so many meds) did some testing to see how long meds were good for. 90 percent were safe and effective long past the expiry. Some up to 10 years! Basically, they take forever to break down, so they might be SLIGHTLY less effective, but I'd bet money they'd still do the trick.

[Sourire]

My DH is a pharmacist and he says that starting about 1 month past the expiry date most medications start becoming less effective. They're probably not dangerous but they may or may not do anything if you take them.