I have been trying to sort out the pharmacy options puzzle lately, and thought I might post my results here for other folks to benefit from if they find themselves in a similar situation. Vials versus Cartridges is the puzzle. Obviously, everyone’s insulin needs and insurance coverages vary, but I was running into a problem that might affect OmniPod or other pump users that EH hadn’t faced when on MDI using the 3ml Humalog cartridges. Common thought is that if you use a pump, you use insulin in vials. I figured this was right too, until I came across a little issue with the definition of a month (30 days, in our case).

I phoned our pharmacy, and currently, as the prescription is written, they’ll only fill for a 30 day supply, which is equivalent to two vials of Humalog (or Novolog). We would prefer a little overage, in case a pod goes bad or whatnot. Humalog Vials:100 units/mL x 10 mL/vial = 1000 units/vial

With no failures, EH is filling the pods with 200u for 3 days worth of delivery, which we decided equaled ~66u a day. If a one month supply of Humalog vials was equal to 31 days, we’d get three vials (2046u total), but with a month’s supply being for 30 days, it’s only two vials (1980u total). If we were requiring 70u a day, that would tip the vials over to 3/month I believe (2100u total). But that’s hard to pull off when it’s obvious to insurance that you can only cram 200u into an OmniPod every 3 days. We could reuse insulin from bad pods, or we could ration much more carefully and hope we were right/eat low carb on Day 3, but that seems silly.

Thus, I think the cheapest and possibly easiest method might be to continue to use the Humalog KwikPen 3ml Cartridges. Because of the amounts in each cartridge, we tip over into the second box very quickly, hence, we would have the required overage needed in case of Pod failure. My reasoning is that they are smaller, and can be refrigerated longer (yes, yes, I know this doesn’t matter, but I was going for every possible convincing point I could come up with for the doctor), and if the active supply is lost, stolen, or breaks, we are not out a 15 day supply, we are only out a 1.75 day supply. (We divide supplies and backups between multiple bags between both of us while traveling for safety purposes.)

Here’s my math:

Humalog KwikPen 3ml Cartridges/5 pack 100 units/mL x 3 mL/cartridge x 5 cartridges/box= 1500u per box

70u/day x 30 days = 2100 units/month = 7 Cartridges/month = 2 Boxes

OR the conservative option

66 units/day x 30 days = 1980 units/month = 7 Cartridges/month = 2 Boxes

So, even conservatively (Rx written for 66 units a day, fills Pod every 3 days, no errors or failures ever) the cartridges would continue to be the cheapest option and give us a little overage in case of disaster.

I might be totally wrong about this. But I think it will mean a small cost savings for us, and could help someone else in the future.