Interesting view. This is not what I have been advised.
When on MDI and travelling, I would always take twice as much insulin as I needed and return with spares which I would return to the fridge when I returned until I next needed a new cartridge. With this approach, I experienced no ill effects.
If you consider my "journey" from pharmacist to home was typically three or four hours (I would pick up my insulin in my lunch break), my insulin would always have a period out of the fridge and then back in again.
I agree this needs to be reviewed if you are unable to keep you insulin cool such as in a Frio bag.
Hi Helen - you are of course correct, I'm assuming (and maybe I should not have) that your are away from a fridge or a frio bag for more that 24hrs or so if you need to take a pen with you as a spare
. But even so when using a frio on holiday when the holiday is over I never put the leftover insulin back in the fridge.
You can keep it at room temp (circa 20c) for 28 days, but you'd need to label your spare pens to remember the one you took out of the fridge last time and when you took it out. I'm also quite sure from experience that you cannot just add up the days until you reach 28, plus remember being told never to put insulin back in the fridge after its been removed (although on long holidays and when flying I've never followed this).
I personally find that after around 3-4 days at 28c or more my insulin in my pump is not as effective and needs changing.