# Expiration of sulfamethoxazole-trimethoprim



## Pawbla

You know how meds always have some time when they're still useful after they've expired... They have to put the expiration date some time ahead just to be safe.
Does anybody know for how long sulfamethoxazole and trimethoprim are still useful after the expiration date?
And do you know if like levamisole and some other meds, they change into a toxic form or something like that after said date?


----------



## Dobato

Pawbla, as long as the med was correctly stored, it will be good considerably longer than the suggested expiry date, have a read of this:

http://www.rense.com/general29/fom.htm

As mentioned in the thread, the worse that can happen with the vast majority of meds, and this would be with very expired meds, is that there would be a loss of some strength. There a few exception for a few very specific drugs, but I am unaware of TMS, being included in these, the mentions are for tetracycline based meds, and there is disagreement on this.

Karyn


----------



## Pawbla

That was why I was asking . I work with rescue dogs a lot, and we use expired meds a ton of times - but there is a "popular knowledge" about which meds are perfectly safe. And I know some can be toxic, like levamisole, as I said. We get expired meds for free many times.
Well, hopefully it won't do any harm. These pills are great, I am throwing away most of the sulfa solution I make . While in powder/pill form they last a lot, prepared with water, they do not.
Thanks


----------



## Larry_Cologne

Came across this thread just now.

I read -- somewhere, don't remember precisely where -- on the internet, I think -- that the use of EXPIRED ANTIBIOTICS can cause *pulmonary problems* (presumably referring to humans, no mention made of species-specific involvement).

I have limited lung function, and am fortunate to have medical insurance, so avoid _antibiotics_ past their expiration date.

I can not verify the accuracy of the information I was provided, but the source seemed authoritative to me at the time.

I have used generic pain relievers (ibuprofen) past the expiry date, with the desired results). Of course, some of my (former) friends think I am crazy, and avoid me at all costs, so it goes to show that YOU NEVER KNOW for sure.... (LOL).


This link also refers to use of *expired antibiotics*:

http://answers.yahoo.com/question/index?qid=20071117003421AAsyJ8m


Larry


----------



## Grimaldy

You might want to take a look at what the Harvard Medical School has to say about expiration dates and why they exist at all:http://www.health.harvard.edu/fhg/updates/update1103a.shtml


----------

