Your injectable medication froze

Kernpunkte

• 01A frozen device is finished, even after it thaws. The prescribing information for these products tells you not to use a pen, syringe or vial that has been frozen. There is no thawing exception written into that instruction, and it does not depend on how the liquid looks afterwards.
• 02You usually cannot see what freezing does. Freezing pushes protein out of solution and lets it clump, and most of the resulting particles are far below the size an eye can resolve. A device can pass every visual check you know how to run and still be one the label tells you to discard.
• 03A clear solution is not proof of an intact protein. People reason that clear and colourless means the medication survived. Clarity only rules out the visible failures, and potency loss after a freeze is not a visible failure.
• 04The visible signs, when they show up at all. Ice crystals, a slushy layer, frosting on the cartridge, cloudiness, floating flakes, a plunger that will not move, or a hairline crack in glass are all worth noting. They confirm a freeze when present, and their absence confirms nothing.
• 05The back wall is where it happens indoors. The coldest part of a domestic fridge is the rear wall where the cooling plate sits, and a carton pressed against it can drop below zero while the middle shelf reads a comfortable 5 degrees. A box shoved to the back is the most common indoor cause.
• 06A gel pack in direct contact is the travel version. A frozen gel pack touching the carton in a cooler bag or a shipping box can freeze medication even when the air in the bag is fine. Cooling devices studied for insulin storage work by holding a range, not by getting as cold as they can.
• 07Cars, doorsteps and checked baggage. Below-freezing outdoor air is the other route in. A pen left in a car overnight in winter, a delivery sitting on a porch, or medication packed in the hold can all reach freezing, which is one reason injectables travel in the cabin.
• 08Home fridges leave the window more often than owners think. Temperature logging in domestic fridges has repeatedly found long stretches outside the labelled 2 to 8 degree range, including time below freezing. Nobody notices, because the appliance only shows a set point rather than what the shelf actually did.
• 09A minimum-recording thermometer is the only honest test. A min/max thermometer sitting next to the medication records the lowest point since you last reset it, which is exactly the number you need. Without one you are left with the position of the carton and whatever you can see.
• 10Keep the device, do not bin it yet. The lot number on the carton is the first thing the pharmacy and the manufacturer will ask for, and a replacement request or a fault report is built on it. Store it somewhere it cannot be picked up by mistake until you have an answer.
• 11Pharmacy first for supply, prescriber for timing. These are two different calls and both are worth making. The pharmacy knows what your plan allows for an early refill, and the prescriber is the only person who should be changing what you take and when.
• 12Ask about a replacement rather than assuming there is none. Manufacturers run patient support lines that sometimes replace a product lost to a documented storage failure, and pharmacies have processes for refills disrupted by a fridge fault. Both work better when you can give a lot number and a date.
• 13Report it, because that is how faults get found. A freeze caused by your own fridge is a household event. A product that arrives frozen, or a device that failed, belongs in a report to the manufacturer and to the regulator, through MedWatch in the United States or your national authority in Europe.
• 14Stop it happening again. Move the medication to the middle shelf and forward of the back wall, keep a min/max thermometer beside it, and never let a frozen gel pack touch the carton. Our post on storing injection supplies covers the rest of the shelf.

Checkliste vor der Injektion

• ✓Do not inject a device or vial you think has frozen, even if it has thawed and looks normal. The labels for these products treat a freeze as the end of that unit's life.
• ✓Set it aside instead of binning it. The pharmacy and the manufacturer will ask for the lot number, and some will ask to see the device.
• ✓Freezing and overheating are opposite excursions with different answers. Our post on medication left out of the fridge covers the warm one, where some labels allow a defined period.
• ✓Nothing here changes your dose or your schedule. Whether to delay, skip or move a dose is a decision your prescriber makes.
• ✓Check the rest of the stock in the same fridge, not only the box you happened to notice.

Schritt-für-Schritt-Anleitung

1. 1

   Put the device down before anything else

   If you were about to inject, stop. A suspected freeze is resolved before the injection, not after it, because there is no way to undo the dose once it is in.

   Pro tip

   Always check the fluid is clear and colourless before injection.
2. 2

   Read the fridge thermometer

   Read the minimum, not the current temperature. The current number tells you what the shelf is doing right now, and the minimum tells you what it did while you were asleep.

   Pro tip

   Always check the fluid is clear and colourless before injection.
3. 3

   Look at where the box was sitting

   Note whether the carton was touching the back wall, sitting under a vent, in the coldest drawer, or pressed against a gel pack in a cooler bag. Position is often the whole explanation.

   Pro tip

   Always check the fluid is clear and colourless before injection.
4. 4

   Look at the liquid in good light

   Hold the device still and look through the window. Ice, slush, frosting, cloudiness, flakes or a plunger that will not move all confirm a problem. Do not shake it to test.

   Pro tip

   Always check the fluid is clear and colourless before injection.
5. 5

   Isolate and mark the device

   Put it in a separate box marked do not use, away from the medication you are still using. Look-alike cartons in the same drawer are how a discarded device gets injected a week later.

   Pro tip

   Always check the fluid is clear and colourless before injection.
6. 6

   Write down the details you will be asked for

   Product name, strength, lot number, expiry date, the minimum temperature you read, and the date you found it. Photograph the thermometer and the carton while both are in front of you.

   Pro tip

   Always check the fluid is clear and colourless before injection.
7. 7

   Call the pharmacy

   The pharmacy handles the supply question, which includes whether an early refill can be processed, what your plan needs, and how the device should be disposed of.

   Pro tip

   Always check the fluid is clear and colourless before injection.
8. 8

   Call the prescriber about timing, and report the fault

   The prescriber handles the dose and schedule question. Separately, report a product that arrived frozen or a device that failed to the manufacturer and to the regulator.

   Pro tip

   Always check the fluid is clear and colourless before injection.

Nach der Injektion

• Write the date, the minimum reading and the lot number in your injection record while they are in front of you.
• Keep the isolated device separate until the pharmacy tells you how to dispose of it.
• Reset the minimum on the thermometer once the reading is written down, so the next period starts clean.
• Check every other box in the same fridge, including anything stored in the door or a drawer.

Häufige Fehler

Häufige Fragen

Quellen

1. Insulin Storage: A Critical Reappraisal. Journal of Diabetes Science and Technology, 2021.
2. Thermal stability and storage of human insulin. Cochrane Database of Systematic Reviews, 2023.
3. Efficacy of alternative cooling devices used for insulin storage without refrigeration under a hot-humid environment. Annals of Medicine, 2022.
4. Novo Nordisk. OZEMPIC (semaglutide) injection, full prescribing information.
5. Eli Lilly. ZEPBOUND (tirzepatide) injection, prescribing information.
6. U.S. Food and Drug Administration. MedWatch: safety information and adverse event reporting program.