The instructions for all insulin pens say not to keep the pen in the refrigerator after first use of the pen. We are supposed to keep them cool/cold (but NOT frozen!) until first use in order to keep the insulin fresh. The directions are very clear however that once a needle has been placed on the pen and the first dose drawn the pen is not supposed to be kept in the refrigerator. Why is this? It seems to me that keeping the insulin cool in the refrigerator at any time would be preferential to not keeping it cool. I can't imagine why that would be a bad thing. The alternative is to leave the pen laying about where it will cycle through daily temperature fluctuations or, even worse, carrying it in a purse or pack where it will be jiggled about and experience even greater temperature fluctuations. So why is it a bad thing to put the pen back in the refrigerator until its next use?
In my case I use only 10 units of Levemir in the morning. (I use another long lasting insulin for my night time bolus.) That means my Levemir pen sometimes lasts longer than the throw-away date after opening. This is even truer for the Symlin which I use even smaller doses of. I seldom toss them on those dates largely because I hate throwing away still-good product and that gets expensive. If I sense any degradation of performance I toss it immediately. Otherwise I push those throw away dates. Do you toss your pens away on such a schedule? I figure if I keep the pen in the refrigerator it is going to stay fresher through the end of the cartridge than not. But the instructions specifically warn against that. I appreciate the insulin companies want to error on the side of safety and fresh insulin so for them it makes sense to insist that a pen be tossed 30 days after opening. What do you think? TIA.