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Keeping Medication Cold

Updated: Aug 2, 2020

Some medications for chronic illnesses—e.g., interferons and glatiramer acetate for multiple sclerosis and insulin for diabetics—need to be temperature controlled or refrigerated. Transporting these DMTs requires care, and after extensive research and testing, ActiveMSers has uncovered an alarming concern: patients likely are accidentally and mis-knowingly freezing their medications.

Polar Bear and Engel donated coolers for testing purposes.As an Amazon Associate I earn from qualifying purchases. These funds help maintain this website. Details.

Polar Bear medication cooler

When I set out to find ways to safely transport medication for an out-of-state trip, my focus was on medication coolers. How well did they work, was it a smart investment, and were they even necessary? But in the process of testing these coolers and reviewing the habits of fellow MSers and other people who toted meds that needed to be temperature controlled, I stumbled on something shocking. Many of us are putting our treatments at risk and potentially unwittingly freezing our drugs.

After a series of tests of both cooling techniques and coolers, ActiveMSers discovered that it is very easy to accidentally freeze or incorrectly store your refrigerated injectable multiple sclerosis medication—Avonex, Copaxone, Rebif, Extavia, Plegridy, Glaptopa, and Betaseron—in a cooler not designed specifically for drug storage. The reason? The ice packs included in your drug shipment are frozen to only 30 degrees, not the zero degrees most household freezers are set to. Reusing the ice packs included with your shipments is potentially hazardous for keeping medications cool. Additionally, placing your medication in or atop ice cubes may freeze your drugs.

Most people at first blush might think coolers to hold your medications—from diabetes and rheumatoid arthritis drugs to asthma and allergy interventions (e.g., Xolair and EpiPens)—might seem a bit like overkill. Seriously, how different can a cooler be? After all, you just need to grab a couple ice packs, toss the meds in an ice chest, and you’re good to go, right? So to test that theory we compared a typical ice chest (an Igloo cooler) to one that was custom-made for general medication (a Polar Bear medical cooler). Then in a twist, we added a cooler that was designed specifically for insulin, not MS meds.

Medication coolers are uniquely designed to keep drugs at a stable temperature. The trick for keeping meds safe: a storage area for your treatment within the cooler that prevents drugs from freezing. Standard ice chests have a singular design: just keep stuff cold. The results of our tests were surprising and eye-opening. The differences were stark.

Medication Coolers

We followed the manufacturer’s instructions for the Polar Bear medical cooler to properly store the medication and then used an indoor/outdoor thermometer to monitor temps. In general, Polar Bear claims its coolers will keep meds at an average of 40 degrees for an indefinite amount of time if the cooling packs are rotated every 10-12 hours. But we aimed to see how one would perform without a refresh.

We conducted the test at a variable room temperature of about 65-75 degrees. With a starting temp of 40.5 degrees when first sealed, the temps in our specialty medical cooler gradually declined to a low temp of 33.3 degrees (hour 1) in just over an hour. It took a total of five hours to reach 34 degrees and another five hours to reach 35 degrees (hour 10). The temperature in the cooler when I hit the hay for the night registered 35.6 degrees and seven hours later registered 41.4 degrees (hour 19). The temps went up nearly five degrees in just two hours and reached 46 degrees in hour 21. At the conclusion of our 24-hour test, the cooler registered 53.1 degrees. Aces. Note: those numbers obviously would be trimmed in warmer temps, justifying the Polar Bear’s conservative 10-12 hour estimate.

Just for grins, and because we have a few ActiveMSers out there who enjoy winter camping and traveling in cold climes (skiers and boarders especially), we then tested how long the cooler would insulate your medication in very cold temperatures. We followed the manufacturer’s instructions for wrapping the “medication,” except the two sheets of their “Techni Ice” were in the mid-60s, not refrigerated or frozen in any way. Then we tossed the entire cooler into the freezer set at zero degrees—think the trunk of your car at Jackson Hole in January on a chilly morning. Based on our tests, it takes a little over eight hours to drop from the 60s to 32 degrees with an outside temperature at a constant zero degrees. So your window to keep your treatment safe certainly is expanded, but it’s finite.

Finally, because anything worth testing is worth over testing, ActiveMSers tested one more medical cooler, one designed originally to carry insulin. After all, it was smaller (think large wallet), more portable, and easier to use than the multi-step cooling process of the Polar Bear coolers tested. What could possibly go wrong? A lot, it turns out. We left the wallet-sized cooler in the freezer for a good 12 hours (at approximately 0 degrees F). This led to serious issues: temps dropped to 16.2 degrees in just 7 minutes and stayed below 32 degrees for nearly 1 hour (55 minutes). I also filled a Copaxone syringe with water, put it in its original packaging, and tested to see if the 1 ml of fluid would freeze. It did, and in under 10 minutes. How could this happen with a product designed for medication? The wallet-sized cooler originally was meant for insulin vials of 10ml; MS medications range in considerably lower volumes: from .2ml to 1ml. You’ve been warned: not all medication coolers are appropriate for all medications.

Standard Coolers

Do you even need a medication cooler, though? For our first test with the Playmate (a far cry from a Yeti, which is insulated out the wazoo), we went basic: plain-Jane ice cubes. So we dumped ice into our Playmate and buried our thermometer—wrapped in a plastic baggie—into the ice. The starting temperature was 34.7 degrees. In two minutes the temperature had dropped to 23.5 degrees! For our next test, we set our thermometer on top of the ice thinking that might be safer. Wrong. Temps started at 35.4 degrees and in seven minutes the temperature had dropped to 25.2 degrees!

Would those cooling packs sent with your meds be any safer? So we took our thermometer, wrapped it in a light cloth, and then sandwiched it between two ice packs, using the large ones that got shipped with the Copaxone I was taking at the time. The drug makers use these ice packs to keep the drugs cold, so why shouldn’t I? Don’t do this at home with your drugs! Temperatures reached the frozen mark in just 13 minutes. By minute 20, with temps threatening to drop below the 26-degree mark, we halted the test.

We kept tweaking. We added an insulating layer of refrigerated gel packs between the frozen ones, making a nice, thick cooling sandwich. Nope, still too cold. For our third test we layered: frozen packs on the bottom, topped by refrigerated packs, topped by meds. Temps reached 52 degrees in 22 minutes—too warm. Alrighty, determined to make this work, we tried another method. We put our “drugs” into a Tupperware container, and then put a double layer of gel packs (cool but not chilled all the way to 36 degrees), and then an icepack on top. Alas, we’re getting closer but still no cigar. Temps started at 46.6 degrees, rose to a high of 48.2 degrees, and then cooled to a steady 46.6 degrees, too high for our 46-degree limit.

Portable Refrigerators/Freezers

Frustrated by the fickleness of standard coolers, ActiveMSers was determined to see if there was another option. What about a portable refrigerator? So we turned to a leader in that department, Engel, which manufactures refrigerator/freezer combos that can plug into your vehicle’s 12-volt cigarette lighter plug. Engel refrigerators/freezers have been field tested in the rugged (and hot) Australian Outback for decades. While usually plied by adventurers on 4x4 adventures, the Engel offers some true appeal to MSers, from keeping meds cool to freezing cooling vests.

Engel portable fridge freezer medication cooler

Power consumption is less than a single headlamp, which means you can leave it plugged in for extended periods with your car only running on auxiliary power (i.e., battery only, not engine). In our tests in the freezer mode, it dropped to -1 degree F in under 45 minutes, impressive. And then curious to see just how well-insulated it was, we crammed our tester full, froze everything solid, then unplugged it. It didn’t reach 32 degrees (0 C) for 13 hours, but more impressively it stayed below 50 degrees for an eye-popping 6.5 days!

When you’re not using your Engel on the road or trail, you can run it in your house, garage, or hotel room from a standard outlet. Naturally it makes for a great second freezer to store all of your cooling gear so it’s ready to go when you are. Of course it also works fine for medication that needs to be refrigerated when you are on the go. (Or bust it out for the ultimate backyard barbecue cooler.) But for drugs alone it is certainly overkill. These coolers start at $650 and range into the four figures. And they are heavy: over 40 lbs empty. So they are not practical for that grab-and-go overnight trip, but for extended remote adventures, it might be your only solution to keep your chocolate from melting so you can enjoy smores.

ActiveMSers Recommendations

When you receive medication in the mail, it is typically shipped with an ice pack or two. We contacted McKesson Pharmacy, the largest mail-order drug company in the US, and asked them what temperature those ice packs were frozen to. They are only frozen to 30 degrees F. Your home freezer is set in the zero-degree range. As our tests have proven, if you use the ice packs frozen to 0 degrees to chill your medication, you will freeze it. ActiveMSers recommends not using those ice packs or to exercise extreme care. Ice cubes are no better. It comes down to science. Damn you, science!!!

There is a common misconception that because ice freezes at 32 degrees, ice stays at 32 degrees. Wrong, wrong, wrong. It’s as cold as the environment. Ice is a solid, just as a rock is a solid, so if ice and rock are hanging around outside together and it’s 3 degrees, both are going to be 3 degrees.

When it comes to your medication, it is just as critical to keep your meds from freezing as is it to keep them from overheating, say in a hot car. Syringes may explode, drugs may become unstable, and the medication may be totally ruined. For that reason, after all of the (admittedly anal) testing, because most MS medications can remain stable at room temps for a time—at least 12 hours—in general it is most important to keep your meds within its full safety window, not necessarily in it’s recommended “refrigerator” window.

Due to the vastly divergent results we received while testing coolers, ActiveMSers strongly recommends NOT using all-purpose coolers for storing your medication during extended travel. We found it difficult to maintain safe temperatures below 46 degrees and, worse, it was far too easy to freeze our multiple sclerosis medications (or any liquid drug for that matter). But for shorter jaunts, putting your drugs in some Tupperware (line it with paper towels for extra insulation) atop some ice should keep your medication safely cool without freezing. So instead of worrying about the safety of your DMTs, you can smartly chill out.

MS Drug Storage Recommendations*

Avonex: Prefilled syringes of Avonex must be refrigerated (36-46°F or 2-8°C) until you are ready to use them. Pre-filled syringes will not lose efficacy or become unusable if left at room temperature for no longer than 12 hours. Avonex in the powdered form may be left at room temperature for up to 30 days.

Copaxone/Glaptopa: Keep your monthly supply of Copaxone pre-filled syringes refrigerated between 36ºF and 46ºF (2ºC-8ºC). Pre-filled syringes may be stored at room temperature between 59ºF and 86ºF (15ºC-30ºC) for up to one month.

Rebif/Plegridy: Rebif and Plegridy should be stored in the refrigerator at 2°–8°C/36°–46°F. Do not freeze. If a refrigerator is not available, Rebif may be stored at or below room temperature (25°C/77°F) for up to 30 days and away from heat and light.

Betaseron/Extavia: Betaseron and Extavia should be stored at room temperature 25°C (77°F), but may be stored between 15 to 30°C (59 to 86°F). Avoid freezing.

* Taken directly from drug manufacturer’s website


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