ChicagoCraig's reminded that I had to throw away medication because I unwittingly took it out during a winter camping trip. From my understanding, nearly all of our over-the-counter medicine doesn't like to go below freezing, so I threw it out (most within 6 months expiration anyway). I've had Wilderness First Aid training, and planned on taking an EMT course some time in the future. Pretty much for both of these, I wouldn't be giving medication to others. I think I know the limits of most of this type of medication (I read the box, and read other things online. Above all, if I screw up, it's my fault).

So, the question I have: How can I take "simple" medications with me when I'm going to be out during below 40F weather? Things like triple anti-biotic cream, anti-diarrhea, and pain meds.

Y'know, I don't know that this is researched well, or if it is, it's not dissiminated well.

I would assume most tablets/capsules are fine in cold weather.

I have heard some liquid meds do poorly in heat (denaturing proteins, things like that). I would assume problems with freezing liquids would occur if you're using vials and such.

My gut instinct, with absolutely no scientific proof, is you'll be fine for a while, for most meds, for a couple days anyway. where did you hear about freezing and OTC meds?

It's a reasonable question to ask. But I have frozen OTC meds of all sorts and they worked fine for weeks/months afterwards. As with excessive heat and excessive humidity it may reduce the shelf life, but that's assumed with all med's in portable kits.

BTW, I chat up the pharmacist (not the assistant) and make sure I get their newest stock. They never give me a hard time when I explain the intended use. (The pharmacists are almost always intelligent, engaging females; but that has no bearing on the issue, or the chatting up. ;-)

I agree that OTC pills probably are not harmed by occasional freezing temps. I don't know about ointments or liquids (eye drops) but they would obviously be difficult to use while frozen. I keep all my meds in a small zippered pouch so that in cold temps I can remove it from my pack and carry it in my pocket. Just remember to put the ointments in individual, sturdy zip locks (sunscreen as well) because they absolutely will leak eventualy.
leo

If you want to be absolutely sure of liquids not freezing you need to wear it under all major insulating layers. My contact lense liquid (essentially just salty water for cleaning the lenses) froze in the inner pocket of my snowmobile suit. That pocket is on the INSIDE of my snowmobile jacket. You should think that my snowmobile suit should be warm enough, but beneath that layer was several more layers of insulation (my snowmobile bib, my fleece sweather as well as wool underwear). . I was snug and warm in -30 C, the contact lens fluid was evidently not. Since then I've always carried essential can't-freeze items in a small pouch under my middle layer.

The OTC medications in my FAK are frozen and unfrozen repeatedly over several months every year where I live. Advil, Benadryl, Pepto-Bismol and decongestants all continue to work, without any noticable loss of efficacy. Neosporin-treated boo-boos don't get infected.

I wear disposable contact lenses, and I'd really like to stick a spare pair and some solution in my BOB, but I doubt they'd survive the frequent freeze/thaw cycle.

What's the risk of using expired or frozen OTC meds? Is it that the med won't be as effective, or can some turn dangerous over time? I tell you the truth I've never thought about that. I even still take Advil that's 2 years expired.

Don't forget that the tapes on most bandages don't work well in the cold.

ki4buc, unless you're going by something authoritative you read, I don't believe that short-term freezing would harm most of the meds in pill/tablet/capsule form that we'd carry, like pain killers, decongestants, anti-diarrheals, etc. Ointments/gels, I don't know, depending on the ingredients. Anything injectable should be kept from freezing due to the high water content. I know for a fact that insulin can't be used if it has ever been allowed to freeze, so definitely protect that from freezing.

MDinana is right, this is a topic that hasn't really been researched that well, at least publicly. I don't doubt that the pharma manufacturers themselves have more data on this topic than is generally known. It was only recently that DoD contracted with the FDA to test the condition of its stockpile of expired meds, particularly those stored under adverse conditions (usually excessive heat, like over in the sandbox, not excessive cold). Freezing could also affect the consistency of a product, even after thawing out. Ingredients could separate during freezing that might not mix together again when thawed, although I doubt that it would affect the actual potency of the active ingredients.

There are actually a few different considerations to storing meds outside the recommended temp range:
* Has the medication become less potent?
* Has it become more toxic?
* Has freezing physically compromised the sterility of the product?

The first two things would seem to be more affected by heat than cold. Freezing would likely tend to significantly slow down any sort of degradation or chemical reactions that affect either the potency or toxicity of the meds. Freezing any solutions could certainly affect its packaging as the ice swells in volume, especially any rigid containers, so the last item would certainly be a consideration in the cold but few of us probably carry anything injectable.

Just a random tidbit, but I suppose condensation is another consideration that could affect the long-term stability of meds when you bring them back into warmer environments from the cold. But short term, it's probably not much of a consideration. I mean, how many people keep their meds in their steamy bathroom medicine cabinets for years?

Anyway, I don't have any more definitive knowledge than anyone else, but that's my take on it. ki4buc, if you've got a reference, I'd be interested in reading up on the issue in case I'm actually way off in my opinion here.

Slightly off topic, I have a friend that used expired sun screen at high altitude and paid the price. His face burned, blistered and peeled 3 times. His lips seven times.

When in doubt, replace. Especially if it's a critical med.

Yooooowwwwwch!!! Thus endeth the debate.

I've been trying to find anything more definitive out there. Ran across a reference in Google to Auerbach's Wilderness Medicine book. I don't own this book and I need some subscription to access it online so I can't read it, but there seems to be an appendix on drug stability that might shed some light on this topic. Does anyone have that book handy who could tell us what it says about freezing meds?

Let me muddle things up with some slightly informed guesswork. The structure/conformation of the active ingredient molecules of the medicine shouldn't be affected by freezing. As temperature drops, molecules "wiggle" less and so are less likely to accidently change into something else.

However, there's a lot more stuff in medicine than just the active ingredient. In dry pills there's time-release coatings, dispersion agents, fillers, binders, and assorted other things which can be affected by lower temperatures. My main concern would be with the time-release coating becoming more brittle and cracking when cold, thereby allowing the active ingredient to hit the body quicker and in a bigger dose than recommended.

In liquid medicines there is a different thing to worry about. Usually the medicinally active molecules do not want to disolve in water so they are dispersed/suspended in the water by surfactants. The ability of surfactants to suspend the medicinal molecules changes with temperature. If the temperature drops too low an irreversible phase-change can occur which destroys the ability of the molecules to stay suspended in the water.

I have no idea if the above concerns are true for medicine, but they are things I have to worry about when designing chemical blends for oil field applications, which is surprisingly similar to medicinal chemistry. "Winterized" chemical blends for the field are a pain in the @$$.

-Blast

Asprin and Ibuprofen are relatively safe and stable.

But, Paracetamol / Acetaminophen typically only has a shelf life of two years and after this can have an upredicatable dose.
Since it's a reasonably nasty overdoze risk anyway (especially with a few drinks or a compromised liver) it's probably the OTC med I would throw out at the date.

If you're taking meds, call your pharmacist and ask.

Sue

So, to be clear, my "understanding" was not a specific document, but personal experience by continually coming across medicine labeled "store at room temperature". With what I have immediately accessible, I see that DayQuil(R) says "store at room temperature", a Peopto-Bismol(tm) chewable tablets (expired, getting tossed) says "avoid excessive heat". CVS brand of Sudafed(R) says 68F - 77F ( 20-25C). I'm pretty sure antibiotics are the same way, but the one I have an info sheet for doesn't say anything.

My concern was mostly with the freeze-thaw cycle, and knowing that other consumables (i.e. chicken) you are not supposed to eat it after re-freezing it twice. This came up because I had the Sudafed(R) and the Pepto-Bismol(tm) in a first aid kit that went on a winter camping trip. Also found out that iodine swaps apparently have an expiration date. Needless to say, most of the medicines in my kit were either exposed to below room temperature or have passed (or near) expiration.

When I have a need to swing by again, I'll ask the pharmacist. My thought is this is going to be very dependent upon the type medicine. This really occurred to me mostly because of the "After Armageddon" show and that "room temperature" should be read as "technologically controlled room temperature", less you forget that normal temperature ranges during the day is about 15-20F.

Sun cream often has a very short shelf-life, around 6 months. So this is interesting but confirms what I'd read.

Usually, medications lose their potency but don't become dangerous. Expired meds can be better than nothing. If you use the standard dosage, the worst that will likely happen is no effect. (It's tempting, then, to use a higher dose, but at that point you are just guessing and there's a real danger of overdose.)

What I'm saying is, it's not like eating food (eg rice) that's been cooked and left out for 24 hours. That does become actively dangerous. Germs grow in it.

I suspect that the 'danger' of meds is simply that they lose some of their potency, rather than becoming dangerous. I know the Army did some testing on meds in high heat, and were surprised that more stuff didn't go bad. IIRC, it was mainly some antibiotics that went bad. I think Neomycin is one with a relatively short shelf life.

The so-called expiration dates printed on the labels are not a good indication of a real expiration date, I believe that is a law. The Army testing indicated that many meds are good for YEARS.

This may have been the article: Many Medicines Are Potent Years Past Expiration Dates

Sue

Ok, I see where you are coming from. I think most pharmacists won't be particularly knowledgeable about the effects of freezing on various medications, except for certain ones which are known have problems, like insulin. I say this because I think their training would more likely emphasize storing meds in whatever temperature range the manufacturer recommends, and therefore, the conventional thinking is that storing them outside this range is "not recommended" or "bad" with little additional information to offer.

As we mentioned earlier, there's been little little research on the topic it seems so little to teach pharmacists about it. And maybe that's because freezing doesn't particularly affect most meds, at least in the short term? <shrug>

Susan pointed out a DoD study we've mentioned in the past on ETS. That was high temp storage but the results did publicize the fact that meds can still be fine beyond their expiration and storage specs, just like you can drink milk beyond the date printed on the top.

I also made another comment in the past about this topic. I'll just link to that old post . I was discussing expiration dates in that post, but it can also apply to storage conditions. Basically it boils down to "proceed at your own risk" if you're exposing meds to conditions outside the manufacturer recommended range and you should do a personal risk-benefit calculation.

If some medication is critical, like some heart medication, then by all means take extra precautions about keeping it from freezing. Or even antiotic ointment if you'll be many days from civilization in case a wound gets infected. But if you're carrying something for headaches or minor aches and pains, then you can probably be less concerned about the effects of freezing. Anyway, my personal, non-pharmacist 2 cents of advice.

EDIT: I'm still interested in finding out what that appendix section of Wildnerness Medicine says about the stability of meds at extreme temperatures, if someone has that book. Maybe there are some surprises, however, I suspect that most of the meds that shouldn't be frozen are injectable and therefore not the kinds of meds that most of us would be carrying around.

Auerbach's excellent books Wilderness Medicine and Field Guide to Wilderness have an appendix entitled Drug Stability Information. The initial sentence is: "Stability data on drug products are derived from studies don in controlled enivormnmental conditions."

A typical use-at-your-risk disclaimer follows, for instance, at the end of the acetaminophen listing: "...Avoid freezing. Stability after freezing is unknown."

Assessments for each listing are quite conservative, and would seem to be based more on appropriate caution because so little cold-weather testing has been done, and therefore there is little real data on which to make recommendations.

It should go without saying that the pharmaceutical manufacturers and sellers have a clear vested interest in selling more product rather than less. The previously mentioned Air Force study is a clear example of most drugs being useful far beyond their printed "expiration date." It's not clear to me what the storage conditions were for the Air Force study; if anything cold weather storage/freezing conditions should make medicines last longer. Pills, capsules, and powders at least, contain essentially no water, so there should be no freeze-thaw cycle concerns as with freshly frozen food-stuffs. Many meds in syrup form are alcohol based, so have their own anti-freeze built in, to survive the low temperatures without freezing most of us have to deal with.

I'll restate an important point. With the exception of tetracycline only, which may degrade into a substance toxic to the kidneys, what happens at some point is loss of potency. There appears to no evidence that you're going to poison yourself by using 6 year old Tylenol or Advil.

I typically use prescription and OTC meds for several years beyond their expiration dates (the exception would be outdated tetracycline); the listed dates are in the drug companies and re-sellers best interests, not mine. I'm willing to wait to see published evidence of harm.

Further research on this would be of interest, and inexpensive to do. I don't think industry funding for it, however, would likely be forthcoming.

Ibuprofen doesn't seem to be bothered by extreme cold weather. Maybe it even helps its shelf life?

I had this happen to a vial of insulin (the cloudy kind, NPH, that is suspended in the liquid) that was left out in the car overnight and froze. When it thawed out the medication that should have been suspended and made it look cloudy just stayed in one clump. Good thing there wasn't much of it left and I had a spare in the fridge. Not sure if it would affect all liquid medicines. FWIW

While this is true, I don't think it is so much a matter of the sneaky drug companies forcing you to buy more medicine before you really have to. Remember, if it expires before they can sell it, they are the ones who take the hit.

It is a mater of practicality. If you are developing a new medicine, are you going to wait around an extra ten years before going to market so that some survivalist will be happy about the expiration date? No, you figure out how long of a shelf life you need to get the product to the consumer and give him a reasonable time to consume it, then test and certify that.