The unofficial theory I’ve heard is: that which makes Apidra® work quicker (remember apidra is Pig Latin for rapid) also makes it more susceptible to “going bad” quicker. I think of it this way: its composition is broken down allowing it to do it’s job faster, but that broken-down state means that it’s closer to losing its potency.
I read this somewhere some time on some forum. It made sense to me so I tend to believe it. I don’t know if it’s accurate.
After using Apidra® for a while and having great success, I started to notice that toward the end of a 1000 u vial of insulin, numbers seemed to creep up a bit. To isolate this variable to be sure the higher BGs coincided with the age of the insulin vial takes data tracking and analysis. The work I did in this area was not extensive, but in general, I think the older the vial, the lesser the potency.
I did not see this with Novolog®. Once I took a vial out of the fridge I didn’t put it back. I continued this practice with Apidra®. I had heard Apidra® was more vulnerable to spoilage from heat. So at first I tried to keep the vials in the fridge between changes. That became cumbersome.
My dear friend, Cari, told me that she uses pen vials for her son’s insulin source (a fellow OmniPodder). This serves two purposes:
1) It allows for flexibility if you need to give an injection. Say you have a pump delivery issue (and yes, ours are almost nonexistent at this point, but not completely eradicated) rather than needing to change a Pod or draw up a dose with a regular needle because perhaps it’s not exactly convenient to do so in the middle of a restaurant or when you’re on the pitcher’s mound, you are prepared with the ease and convenience of an insulin pen.
2) The amount of insulin you have unrefrigerated at any time is significantly less. The vials are 300 u rather than 1000 u. Instead of using one vial per month, we’re using one a week.
Poof! The monthly bg creep issue was eliminated. I no longer worry about the age of the insulin and whether it’s gone bad.
With so many variables to manage with diabetes, being able to eliminate one is a win! With two day site changes and smaller vials, we’re up to two! Win, win!!