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  • Freezing meds

    the other day I happened to mention to a person at work that I kept unused prescriptions in the freezer. Mainly these are Tylonol/Codine painkiller tablets and antibiotic capsuls from the dentist. This person indicated that i should take them out of the freezer and keep them at room temp. Theyalso said this was from their pharmo experience. I looked on the inet for info but can't find any. so is this true? that i should NOT store Rx i the freezer but at room temp instead? I have tried the 1997 expiration stuff and it is still good.

  • #2
    Actually freezing virtually any form of "dry" medication is helpful for extending the useful life of same. What you cannot freeze are liquid medications.

    By freezing you slow the rate of molecular activity. It is that activity that causes "aging" of the medications. To achieve zero aging you need absolute zero temps, anything but practical, but for your purposes a good deep freeze works to measureably extend the lifespan.

    Not sure what pharmaceutical experience your friend has, but room temp, or cool and dry are the standard admonitions. But then so is destroy any meds past their expiry date. For various reasons keeping meds long term is not encouraged by non-preparedness minded people, so take it for what it is worth.


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    Tricks and treachery are the practice of fools, that don't have brains enough to be honest. - Benjamin Franklin

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    • #3
      Thanks RR, That is what I thought too but this person was a SSgt in the AF and really sounded like they knew what they were talking about (but I still questioned their reasoning). As long as it don't get wet I can't see how freezing dry meds will harm them.


      • #4
        I've been told that antibiotics are dangerous after a specified period of time.
        Usually because they actually decompose, and in so doing, produce toxins as a by-product.
        As for alkloids, like Codeine. I would think it would last indefinitely, as long as kept out of sunlight, and dry, and would increse it survivability.


        • #5
          Actually that pertained to Tetracycline specifically, dating back to a study done in the 60's, that said it became toxic to the kidneys. The study has often been disputed but remains widely quoted.

          However, since then most meds have been formulated so that they simply lose potency over time and do NOT become toxic. Tet has reportedly undergone the same reformulation. Any risk with using expired meds is normally due to lack of efficacy when it is needed as opposed to becoming toxic with age.


          Got sutures?
          Tricks and treachery are the practice of fools, that don't have brains enough to be honest. - Benjamin Franklin

          I have but one person on my ignore list. Can you guess who it is?


          • #6
            Tetracycline is the only antibiotic that I've ever heard of going toxic over time. As RR said, the majority just lose potency. I would be wary of this reformulation or not, and also would be leary of same effects in Doxycycline. But I also on the other hand have no problem in using Tet after experiation for a reasonable time if kept in regular packaging, and for a much longer time if it was kept frozen(as I do with my dry meds).


            • #7
              Tetracycline is the only antibiotic I know for sure goes toxic. I haven't heard of this being disproven, but I have heard that the new formulations don't become toxic with age. Until I see it in a peer reviewed article of text, I wouldn't depend on it.

              My wife, an MD by education, is distrustful of anything that she doesn't recognize as being from a non TC family. IE, if it is an antibiotic, and she doesn't know the name out it goes after 1 year or the original expiration date.

              The FDA rules on expirations require the drug to be at 100% potency at the expiration date when stored in marginal conditions. Marginal being a poorly cooled building, not the glove compartment of a car in miami, FL.

              I've got a report here somewhere from the army or navy looking at meds exposed to extreme cold. The real dangers are beach of at least the sterility of the container, or that freezing will cause part of the med to percipitate out. Neither of these are a concern with solid dose forms. Or, as I said on MS, a pill is already frozen at room temperature.


              • #8

                your note about FDA regs is BBBBAAAADDDD info! - it's must retain 90% and times are generally 1-2 years before experation, though sometimes 1 year if it's new and unproven or a known trouble maker.

                There are a handfull of known trouble makers, unfortunatly, many of the common emergency drugs belong to this "hand full" (thanks Murphy!)

                RR's rules of thumb are right on! - in general, freeze solids and refrigerate liquids. There are exceptions, for example pepto-bizmo should never be refrigerated.

                there is a list of about 200 drugs that should not be refrigerated. If you have a passing familiarity w/ pharmacology, you might recognize 1/2 a dozen of them. If you are a MD you might recognize 3 dozen of them - most are rare birds...

                here are some notes (VERY DRAFT) of a paper I'm working on about the use of expired drugs - DON'T rely on this info!!!!!!!
                Guide to using expired meds

                Most drugs have a wide range or “window” of therapeutic plasma concentrations, and they do not degrade to potent toxic products. Therefore, relatively large variability in the bioavailable or absorbed dose usually does not alter clinical response.[N4] An acceptable amount of active ingredient remaining in a drug is considered to be 90-110% according to the USP[ADDREF] and the IP[ADDREFF] while the BP[ADDREFF] is somewhat more stringent, only allowing 95-110% for variation. Drugs having a percentage of active ingredients within this window are said to not effect clinical response and thus have not degraded to the point of being unusable. According to WHO, drugs that have degraded to 90% or below of active ingredient, have “undergone gross degradation”. Simple degradation tests have been developed to detect these changes, where possible.[ADDREF]

                Any loss of effectiveness should not be compensated for by administering
                Enemies of drug stability”
                Freezing is only detrimental to large protein molecules. It may disrupt suspensions such as antacids and syrups (i.e. Antacids and paracetamol syrup), but should not effect the drug itself. [T6] Freezing is actually beneficial for the majority of drugs. Lowering the temperature causes the rate of molecular activity to slow down. This activity is responsible for drugs loosing their effectiveness. This generally works for any dry dosage form, but may have adverse effects on liquids, suppositories, creams and ointments, etc. that are more related to the suspension medium than the active ingredient.
                Heat will accelerate the degradation of all drugs, but most are suprisingly resilient to it’s detrimental effects. The effects of heat are especially hazardous in a car as the temperature in a closed vehicle can easily reach 130 – 150 deg F, on a 90 degree day.[N4][T6] Many emergency drugs are heat sensitive.[T6]
                Specific drugs that are heat sensitive include: Benzylpenicillin (which may denature), Digoxin tablets and enteric coated prednisolone, all 3 of which are supposed to be stored at under 25 deg C (77 deg F). Most oral antibiotics are also supposed to be stored in a cool dry place.[T6]
                The use of thermally insulated boxes[T6], refrigeration or freezing may provide a satisfactory solution to most storage problems.
                Dangers of using expired or improperly stored drugs:
                Subtheraputic Potency can result in delayed healing, no relief, or a worsening prognosis. This may lead to prescribing a less suitable medication under the mistaken belief that the initial drug therapy failed.[N4] Fatalities due to ineffectiveness; i.e. Less than desired results, can result in some specific cases, specifically with adrenaline[R5] and {DRUGS TO STOP POST-PARTEM HEMORAGE – FILL IN DATA} Antibiotics that have expired and become less active, may encourage resistant strains.[F6]
                Toxicity of degradation products[N4]
                Increasing the likelihood of an allergic reaction (anaphylaxis)[T6]

                Inspection of drugs:
                Smell – this is not effective for detecting changes in most drugs, the notable exception is Aspirin which gives off a acetic acid odor when it’s gone bad.[N4]
                Visual inspection is not always reliable, as many drugs will appear fine when in fact they are severally degraded.[N4] It can be a reliable indicator for some drugs, however. By dosage forms:
                Capsules – hardening or softening, cracking, swelling, or discoloration.[W7]
                Solid tablets – excessive powder and/or pieces of tablets at the bottom of the container (from abraded, crushed or broken tablets). Cracks or chips in the tablets, swelling, mottling, discoloration, fusion of tablets. Appearance of crystals on the walls of the container or on the tablets.[W7]
                Parental solutions
                Solutions in ampoules and vials
                Solutions and suspensions for oral administration
                Bottled powders with a shelf life of 2 weeks or less after being reconstituted
                Liquid filled capsules
                Trasndermal patches
                {DOESN”T FIT HERE: products in which a medicinal ingredient is a beta-lactam antibiotic, peptide or protein}
                creams and ointments

                Basic Tests
                Drugs on WHO’s Essential Drug List that degrade
                Storing drugs

                Drugs people are most going to want to know about are antis, Epi, atropine, lidocaine family, nitro, steroids, antiinflammatories, analgesics in all forms
                R. Rascal says:
                Insulin of course, that's a biggie
                R. Rascal says:
                Seizure meds
                That's why I recommend Nitrospray, MUCH longer life than the tabs once opened
                Dosage form
                1. tablet coated G uncoated G
                2. capsule hard G soft G
                3. injection liquid G powder G
                4. oral liquid solution G suspension G
                5. topical semi-solid cream G ointment G
                6. eye preparations liquid G semi-solid G
                7. other (please state)

                The answer sheet is to be completed for drug products mentioned in the following list of essential drugs for which you have experienced stability problems:
                acetylsalicylic acid
                glyceryl trinitrate
                isosorbide dinitrate
                sulfamethoxazole + trimethoprim
                suxamethonium bromide

                Organoleptic Microbial
                1. change of colour G 1. microorganisms visible G
                2. visible changes, i.e. capping, cracking, foamG 2. tests for bacteria positive G
                3. inhomogeneous appearance G 3. tests for fungi positive G
                4. crystallization G 4. tests for pyrogens positive G
                5. particles, turbidity, precipitation G 5. other (please state)
                6. sedimentation, caking, agglomeration G
                7. smell, i.e. gas formation G
                8. rancidity G Additional information
                9. phase separation of emulsion G .................................................. .....
                10. interaction with packaging material G .................................................. .....
                11. other (please state) .................................................. .....

                Most pharmaceuticals past their expiry date become less efficacious and a few may develop a different adverse drug reaction profile. There are some categories of expired drugs or defective disposal practices that carry a public health risk.

                1. the vast majority of pharmaceuticals are donated with the intention to help; there are only rare occurrences of “dumping” by unscrupulous companies to gain tax relief or off-load unwanted stock;
                2. when pharmaceuticals pass their expiry date they do not automatically become hazardous, they simply becomes less efficacious;

                There are currently no international conventions regulating transfer of pharmaceutical products across frontiers. However, expired or spoiled pharmaceuticals are considered as hazardous waste and as such, if transferred across frontiers, become regulated and subject to the Basel Convention on the Transfrontier Shipment of Hazardous Wastes7,8,9. This involves prescribed procedures to obtain permission to cross international borders along the transit route prior to actual transport. These procedures can take several months to complete.

                different categories by dosage form, (capsules, powders, solutions, suppositories, syrups, tablets).

                Pharmaceuticals that should never be used and should always be considered as pharmaceutical waste are:
                 all expired pharmaceuticals;
                 all unsealed syrups or eye drops (expired or unexpired);
                 all cold chain damaged unexpired pharmaceuticals that should have been stored in a cold chain but were not (for example: insulin, polypeptide hormones, gamma globulins and vaccines);
                 all bulk or loose tablets and capsules. If unexpired these should only be used when the container is still sealed, properly labelled or still within the original unbroken blister packs;
                all unsealed tubes of creams, ointments, etc. (expired or unexpired).

                Sorted by dosage form (all other pharmaceuticals):
                solids, semi-solids and powders
                 tablets, capsules, granules, powders for injection, mixtures, creams, lotions, gels, suppositories, etc.;
                 solutions, suspensions, syrups, etc.;
                 ampoules;
                aerosol canisters
                including propellant-driven sprays and inhalers.
                In general disinfectants do not have an expiry date. They can be stored and gradually used over time so there is no real need to dispose of them. Large quantities of disinfectants must not be flushed into the sewer, as they may kill the bacteria in a sewage works and so stop the biological treatment of the sewage. Similarly large quantities should not be put into watercourses since the disinfectants will damage aquatic life. Small quantities of diluted disinfectant may be disposed of by discharge to a sewer


                • #9
                  oops! - make that 2-3 years for FDA regs!

                  I would be VERY interested in getting a copy of that Navy study you mentioned! - please contact me!


                  • #10
                    Please also take note that by FDA regulation no medical item or medication may carry an expiry date of more than 5 years.

                    Manufacturers are free to short-date as they please for what ever reasons they please. Thus you may see (Terumo is one brand) IV catheters with an expiry date of a year. Sneaky way of turning over stock that essentially does not expire. Short dating is not the least unkown with pharamceuticals either. If called to task all they have to say is "per the advice of legal counsel...."

                    The study that claimed toxicity in Tetracycline was performed in the 60's, was not duplicated and has been called to task since but that "common knowlege" persists widely.

                    The Air Force did do an ongoing study of various meds and was able to obtain FDA recertification of many of them for years. In the case of the nerve agent kits tested they were still being recertified up to 18 years after the original expiry date. Tet was one of the meds recertified after being stored in temps up to 130 degrees for 2 years in (?) Bahrain.

                    Now they did find interestingly enough that some meds from the *same batches* did not test equally, so it's just as possible that even within date you may be getting meds that have lost potency. There was no rhyme or reason between the meds tested either, as in Tet was consistant or morphine or whatever.

                    But when all is said and done freezing dry forms of meds for any we peons are likely to acquire will NOT harm them and only HELP extend the useful shelf life.


                    Got sutures?
                    Tricks and treachery are the practice of fools, that don't have brains enough to be honest. - Benjamin Franklin

                    I have but one person on my ignore list. Can you guess who it is?


                    • #11
                      One job I did in Central America back in the 80's was to help deliver a load of donated meds to friendlies in a disputed zone and I noticed that everything was either past date or out of date. The doctor explained to me that he had them "recertified" through some process that was helped through by the state department and had nothing to do with the actual chemical formula for the drugs, but that the recertifications were different for every drug. That said, I am confused in this matter since I am hearing different stories on it.

                      The common survival drugs that have been reccomended are what I was told are basic pain killers and antibiotics.

                      Lidocane (local pain killer for pre-op wound treatment or operations) probably a prescription item. The medics used this on me a lot before sewing something up or cutting out an ingrown toenail. Seems like it would be pretty useful for any wound treatment, especially if you have to dig shrapnel out of someone and sew them up.

                      Cipro-Dex A mexican brand antibiotic again probably a prescription item in the US, but I am told is over-the-counter in Mexico. I don't know much about it, but it is available and reccomended. Reccomended in a few travel guides for people going backwoods in Central America.

                      Amoxicillen - Common antibiotic. I think this one is available through veterinarian suppliers. Farmers always seemed to have it around when I was a kid.

                      Motrin, Ibruprofin. Over the counter pain killers but the medics carried high dosage forms. I go strep throat in boot camp and they put me on 400mg of it three times a day. I could not feel anything below my knees while I was on the heavy dosages, but I built up a tolerance for it. I keep the over the counter stuff around, but notice that the bottle usually goes out of date before I use it up. Is this something that I can keep around or should I throw it away? It sure is not too cheap and I would rather keep it around if I can.

                      I think penicillen is out since some people are going to be allergic to it.

                      Can anybody tell me how these hold up compared to their respective expiration dates?

                      My take on survival situations is that infection is probably going to be your biggest problem, especially from a wound or animal bite. What is the best all purpose anti-biotic with the longest most safe and stable shelf life?

                      [This message has been edited by RT (edited 13 February 2002).]
                      Life, Liberty and the pursuit of those who threaten them.


                      • #12
                        Let's see if I can answer some of your questions.

                        Lidocaine is an Rx item in the US. That said, it can be acquired indirectly by way of procedure kits that happen (in some cases, not all) to have small vials of it as part of the inventory. Usually these are sold on the veterinary market as outdates or surplus. One of those loopholes like aquarium antibiotics. The kits may be outdated or not. I can say with certainty that outdated Lidocaine, or Xylocaine, etc, still remain useful. You might have to use more but the toxicity level is well beyond what you could find contained in even several kits. Well beyond. But we are talking about drugs that are quite stable over time and lose their potency rather slowly.

                        Now as far as Penicillin allergies, yes, a significant portion of the population does exhibit some allergic symptoms, myself included. But I still use the oral forms with only minor reactions at best, like skin flushing. True anaphylactic reactions are very uncommon. Having Epinephrine and/or Benadryl on hand is a good idea, no matter what meds you are using. Amoxicillin is a Penicllin-related drug, as is Pen VK and others. So don't discount it out of hand.

                        Cipro-Dex unless I am mistaken is Ciprofloxacin or of the same family, so yes, Rx here in the states. But is you have access to Mexican pharmacies by all means obtain what you can. Just don't consider it your mainline antibiotic. Cipro has its own set of problems and does not replace other anti's as far as its effectiveness on various bugs. There is no one antibiotic that kills all bugs.

                        Ibuprofen should be at the top of everyone's list of meds to stash in quantity. Analgesic, anti-inflammatory, anti-pyrrhetic (fever reducing) properties make it the choice over such as Tylenol which does not reduce inflammation. You can mimic Rx doses by increasing your dose to 800 mgs safely. Normally you can buy 200 mg tabs of generic versions. Take 4 tabs and voila'! It truly should be a mainstay. Sam's Club sells large (500 or 1,000 tabs) bottles for less than $10. Stock up at least one bottle per person of adolesence and older age.

                        As discussed above, freeze dry meds, the colder the better. What you want to do, is reduce molecular motion. All molecules are in constant motion above absolute zero. It is the motion of these that causes all elements to deteriorate over time. Lowering the temp reduces that motion and the rate of decay, and thus the rate of loss of potency in meds.

                        Now as far as how long things retain full potency compared to printed dates, that has yet to be determined well enough to offer a schedule. My personal thoughts, based upon all I have been able to find the past few years, is for any med you or I am likely to obtain through rational means (holding up a university hospital pharmacy is not rational even if the Big One has dropped IMHO) should be considered within 90% of rated potency for 2 years stored cool and dry and dark.

                        I have meds expiry dated 3 years ago that I trust. Enteric coated aspirin, for instance, remains viable much longer than uncoated aspirin. Aspirin, BTW, becomes toxic with age. In this case toxicity means increased stomach distress. To become truly lethal you have to take a dose that would be lethal even if it were fresh off the manufacturing line. IOW it'd cause bleeding internally.

                        Consider other common meds. Calamine lotion. Does somewhat less potency mean it's useless? Not hardly, just that it may not reduce the itching quite as well or as fast, if even that.

                        Now, as Tnagent pointed out above a few meds offer their own dangers when potency is reduced significantly, chiefly because the expected result of administration is not achieved. Adrenalin falls into this category. Instead of achieving the desired result with 0.3 or 0.5 mg you may have to use the entire 1.0 mg in the vial. Only time and patient reaction will tell. So if you can keep such meds fresh so much the better. Though it has been opined that the temps reached in ambulance drug compartments may be seriously degrading the Epinephrine (generic is Adrenaline) no one seems to have performed any studies to this effect save to record temps.

                        Under austere conditions liability is far less of a concern than effectiveness. Therefore outdated meds may be your only choice, much as happens in some third world countries.


                        Got sutures?
                        Tricks and treachery are the practice of fools, that don't have brains enough to be honest. - Benjamin Franklin

                        I have but one person on my ignore list. Can you guess who it is?


                        • #13
                          <BLOCKQUOTE>quote:</font><HR>Originally posted by tangent:

                          your note about FDA regs is BBBBAAAADDDD info! - it's must retain 90% and times are generally 1-2 years before experation, though sometimes 1 year if it's new and unproven or a known trouble maker.

                          That is a quote right out of an article on drug stability in an industrial chemical magazine. It is not what I would have expected, but it does make some sense- when you take a 100 gm dose of X, you are guarenteed 100 gm if used before the expiration date, and stored under prescribed conditions.

                          I won't be back home for another week or so, but I will post the cite for the military article. There was another article with less hard information in a magazine called something like "Drug and Cosmetics Industry" It was cited as a reference in the first article.

                          Also I found a book called Drug Stability, but it had little useful information to a user.

                          If you want to send me a snail mail address or fax number, I can send you both articles.


                          • #14
                            CB - that is actually NOT a quote out of a industrial chem mag, but if it's that close, I would like to read that artical too! do you have a ref?

                            on the other 2 articals, your profile does not include a e-mail address. please come over to MedTech and register and I will private message you my snail mail address - the 2 articals would be most appriciated!

                            btw: to clarify: you are NOT guaranteed 100mg if used before the expiration date, you are guaranteed 90. Granted, some manufacturers will put in 110mg so you will have 100mg, but these are the minority. Well, that's theory. In practice, the FDA says to provide a date - any date, when you can guarantee this 90% ammount - most drugs are good MUCH longer than that!

                            [This message has been edited by tangent (edited 23 February 2002).]


                            • #15
                              Drugs Exposed to Extreme Cold, Report 963, Naval Submarine Medical Research Lab., Subbase Groton, Conn.

                              Effects of Cold and Freezing Temperatures on Pharmaceutical Dossage Forms, D&CI, Jan 1980

                              D&CI stands for Drug and Cosmetic Industry, IIRC.

                              I'll copy the articles next time I'm home.