I know that this is something we shouldn't do. But I've seen a video on YouTube demonstrating how to do this and I'm sorely tempted to go ahead and do it myself. My 11-year-old daughter has T1D and just started pumping with the Omnipod on 06/02/2014. Our experience has been very positive so far, and we just love this pump. But my daughter is still honeymooning and uses an average of only 19 units a day max. This means that at the end of day 3 there is at least 28 units of insulin remaining in her Pod. I hate to waste things, and as we all know, insulin isn't free.
I realize that there is a risk of contamination when you withdraw insulin from a Pod in order to reuse it, but I'm meticulous about keeping things as sterile as possible when withdrawing insulin from the vial or cartridge, filling the new Pod, prepping my daughter's skin and handling the filled Pod prior to attaching and activating it. In addition to the risk of infection, are there any other obvious reasons why withdrawing insulin from a used Pod and reusing it to fill the next Pod is a bad idea? Also, how many of you do this or have ever done this? How often do you do it? If you have done or continue to do this, have you ever had an adverse outcome?
We do this and our CDE trainer told us it’s ok. We usually only do if the pod is under 24 hrs old. We had the prescription upped to cover the “waste”. If the insulin has been in the pod next to her body for 3 days - esp in summer - I’d worry more about spoiled insulin that no longer works than contamination.
Your biggest risk is stale insulin. Insulin survives at body temp only 3 days, the main reason for Omnipod's 3 day limit. With the pod against the body, the insulin is always at body temp. So after three days, any insulin left is basically no longer valid and will not do it's job. So you risk only causing your daughter to have higher BG values, which of course is not a good thing. If the YouTube video is the one I've seen, they pulled the insulin out only before one day passed, which is usually considered fine because 4 days is long for insulin but still good enough to allow for the lack of waste of the insulin.
I just spent the last 45 minutes or so searching through YouTube to find that damned video, but no luck. Sorry. I'll be sure to post a link if I ever find it again. But if memory serves, the person in the video withdrew the insulin using a syringe needle inserted into the same spot on the Pod that you use when you inject insulin into a new Pod. (I can't recall whether they used the same syringe as the one that comes in the Pod package or a "typical" insulin syringe one uses to inject insulin old school style.)
As far as Humalog is concerned, it's actually closer to 7 days. I copied the following directly from the Eli Lilly medication information sheet:
Use in an External Insulin Pump — Change the HUMALOG in the reservoir at least every 7 days, change the infusion sets and the infusion set insertion site at least every 3 days or after exposure to temperatures that exceed 98.6°F.
Of course, YDMV and you personally may find that your insulin is not as potent after 3 days. As far as exposure to ambient temperatures higher 98.6 F, your body keeps the insulin in your Pod at the same temperature as your body, i.e. if you are in an environment that is warmer than 98.6 F, your body actually keeps your insulin cooler than the higher temperature outside.
Despite the above, I agree that it gets a little too "iffy" after one day, and I probably wouldn't be comfortable withdrawing insulin from the Pod after 24 hours.
Have you thought about putting a little less insulin in the pod? I haven’t researched that so I’m not sure how much insulin needs to be put in for it to beep. You mentioned having about 28 units left. Maybe put 175 or 180 units into the pod instead. We have a very high deductible and pay well over $250 for 3 boxes per month until we meet our deductible. Then it is $40, which is still high but not as painful, so I understand wanting to save every drop instead of throwing it out with the pod. Good luck.