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From: "Steve Harris" <>
Subject: Re: Shelf life of Antibiotics
Date: Mon, 28 May 2001 20:29:55 -0700

Bob wrote in message <>...
>On Mon, 28 May 2001 18:08:19 -0700, Anonymous
><anonymous@anonymous.anonymous> wrote:
>>What is the shelf life of Antibiotics?  If I've been diagnosed with a
>>simple urinary tract infection, and told to take Cipro 250mg, and I've
>>still got some "sample" Cipro tablets which have been sitting in my
>>bathroom drawer for six months (never opened), would it be okay to take
>>those?  Or do they "go bad" over time?
>They should have an expiration date on them. It is conservative, but
>at least gives you a guide.
>One antibiotic (I forget which) does tend to give a toxic product upon
>long storage. More commonly, it would simply be a loss of potency.

Yep. Basically, tetracyclines of any kind can become toxic after the
expiration date and should be tossed out promptly.

The others are probably good for long after the expiration date,
depending of course on many intangibles, chiefly humidity and packaging.
Single unit dose and unopened "sample" antibiotics packaged with little
absorbent cartridges probably last for years beyond the formal 1 year
expiration. And, as noted above, the worst danger from them is loss of
potency, which probably won't be complete until the tablet has completely

Nobody is going to tell you to take something after its expiration date.
Realistically, however, ciprofloxicin is a particularly tough molecule, due
to being fluorinated. An unopened sample of cipro is probably fine. Can
I recommend you take it?  Of course not. -)


From: "Steve Harris" <>
Subject: Re: Shelf life of Antibiotics & Tetracyclines in particular
Date: Tue, 29 May 2001 00:57:00 -0700

Anonymous wrote in message <3b133003$1_2@anonymous>...
>In a prior post, I asked about potential problems with taking Antibiotics
>after being been stored for a while (a few months).  A few of the
>responses mentioned that "Tetracyclines" were potentially toxic after
>their date of expiration.
>Which antibiotics qualify as "tetracyclines"?  I do a Internet search on
>the word "tetracyclines", and come up only with tetracycline itself, as
>in, one antibiotic.  Is this a family of Antibiotics known as
>tetracyclines, and if so, more importantly (and specifically), is
>Doxycyclene considered a "tetracycline" Antibiotic?
>Again, any responses would be appreciated.  Thank you!!!

Yes. Tetracycline is both a specific drug and a class of drugs.
Tetracycline, doxycycline and minocycline are about the only 3
tetracyclines in use these days. It's very rare to see any others. I
think I'd be very careful about expiration on any of these. There are the
generic names, of course, and the brand names may vary.


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