Does the prescription muscle relaxer "Flexeril" ever expire? I have a
partially used prescription from a couple of years ago, and I'd really
like to take one, if it's safe. I'm having intense muscle spasms and
my doc is only available on Tuesdays and Thursdays.

Hi Luckeyme,

I've taken a look at the "monographs" (patient information reports) in
the MedMaster and USP DI Advice for the Patient drug guides (available
online via MedlinePlus at www.medlineplus.gov) for Cyclobenzaprine
(Flexeril) and would strongly urge you to stop taking the medicine
until you've talked to your doctor.  Note that I am not a physician,
I'm a librarian, and I am not qualified to give you medical advice,
but from what I've read in these reports this particular drug is
somewhat unstable in storage and there's no telling whether it has
broken down to a different compound by now.  Both reports have strong
statements warning patients against taking expired pills, and both
suggest cool, dry storage in a tightly sealed container out of the
light (which I understand from your comment that you've done).

Crabcakes is right that all medicines come with warnings against
taking them after their expiry date - and sometimes that's just
because they loose effectiveness, but sometimes it's because they
become actually harmful (I once had a severe reaction to some out of
date eye antibiotics).  To my mind, it's not worth risking it.  I know
this is not what you really want to hear, sorry!  In the case of this
particular drug, the fact that it can interact with so many other
drugs and compounds suggests to me that, at the very least, you
shouldn't take it unless you've checked with your doctor first, even
if the medicine was new.  It's a little freaky the list of things it
could react with - even vitamins!

If you'd like to take a look at the reports for yourself, they're free on the web:

USP DI Advice for the Patient: Cyclobenzaprine (Systemic)
http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/202172.html

MedMaster: Cyclobenzaprine
http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a682514.html

As I mentioned above, I found these in the MedlinePlus consumer health
system from the National Library of Medicine.

I would suggest you contact your doctor's office (even if your doctor
isn't available) and ask to talk to your doctor's nurse (or one that
is on call).  Actually, since it is the weekend, I suggest you call an
on-call nursing hotline for your area and see what can be done in your
case.  Considering the severity of your pain you should be able to at
least talk to someone affiliated with your physician to get your
problem resolved.  You may be able to get your prescription renewed by
telephone with your doctor's office before you're able to get in to
see the doc.

Good luck, and I sincerely hope your pain goes away soon!  Let me know
if I can clarify this answer in any way -

Librariankt

---

Clarification of Answer by librariankt-ga on 07 Jun 2004 06:17 PDT

Well, thanks for the tip!  I hope you're feeling better, good luck!  Librariankt

You're absolutely right- I did take one, and didn't feel so hot. I
didn't take another one. I'm just going to wait to see my doctor; it
was never very effective anyway, even when it was new. Thanks again,
you've been very helpful. I wasn't aware that medication could
actually break down into harmful components. Thank you!!!

i am not a doctor but expiration just makes the prescription possibly
less effective, you should be fine to take it

There isn't even an expiration date on the prescription bottle. Just a
"date filled". Thanks for your comment, I'm hurtin'!!! -Luckeyme

Without researching this, I'd advise against taking any "old"
prescriptions. pH changes can cause some drugs to deteriorate into
harmful substances. Each drug has a different shelf life, and the
conditions in which your prescription is stored may affect it as well.
(Ex. in a damp bathroom)

I sure hope not, because I just took one. This medication was kept in
its original bottle in a cool, dry cupboard. So I'll cross my fingers.
Thanks for your time!