OmniPod: Vials vs. Cartridges

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. :slight_smile:


I doubt anyone would do the math. If you get a script for 70 units a day, it is doubtful someone would say that doesn’t add up to 200 units every 3 days and reject it. Plus the omnipods actually hold 205+ units (undocumented feature, trust me :wink:). And you could say you need to replace a pod every 2.5 days instead of 3.

But the pens would give you the option of going back to pen injection if you want to, in case of emergency if your PDM breaks or something. So the pens is not a bad choice.

My understanding is the math the pharmacies do is the units per day multiplied by the number of days being filled for divided by the number of units in the container and then rounded up. Without regard for what sort of a device you might be putting the insulin into.

So for example we have a prescription for 150 units per day. We fill for a 30 day period. 150 * 30 = 4500 units. We get this in vials. So 4500 / 1000 = 4.5. The pharmacy can not give fractions of a vial of course, so they round up to 5 vials.

I go back to the pharmacy when we are down to 1 vial left.

One other thing to mention. There is waste with any pump. You need a script for more than you are using. This is very important!

I your endo won’t write it for you, we can txt and I will tell you some ways to make it show up on your PDM that you are using whatever you want it to say. You can bring it to your endo and show him you are averaging 80 units a day, 90 a day whatever you want.

I am literally, again, on the phone with the pharmacy and they are saying just that. Sooooo…we shall see.

Actually, the endo seems to not be the problem. She was very understanding and helpful.

Sorry, not sure which you meant!

Are they saying, “Hey, 70 units x 3 doesn’t add up to 200!” ?

Or are they saying, “Don’t worry, it doesn’t matter.” ?

Either way, get the script for 85 or something.

Or go overboard and get the script for 150.
I don’t feel we abuse it as we don’t refill at 30 days but rather when we are down to 1 vial left.

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Well, they are saying “as written we can only fill it for a 22 day supply” so it does happen to be the endo after all.

It is really difficult to participate in a completely opaque experience, and yet have a very strong opinion about how we want it to turn out. With the electronic prescriptions these days, you have no idea what was written or not.

There’s waste the endo needs to factor in, as well as a safety cushion.

If your endo won’t do what needs to be done for you, let’s talk. There’s an easy fix which I won’t post but can definitely tell you.

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Thanks for teeing up this issue! In addition to the great suggestions already shared, here are a few things I discussed with my Endo:

Reasons supporting requests for incremental units of insulin

  1. Injections to treat stubborn highs. When I had my first POD failure (and you’ve already learned that they will happen), I had to treat the resulting high with injections from the vial and backup syringe I had.
  2. Planning for sick day issues. BG’s can get crazy high fast - I’ve learned that a quick injection can help mitigate some of the spikes.
  3. Frequency of POD changes - based on feedback from other POD users, when I discussed my first pump RX with my Endo I asked her to write the script for POD changes every 2 days to allow for a learning curve and/or other failures/attrition. My Endo agreed and wrote it that way from the start.

I’m so happy to have an Endo that listens to my questions/ concerns. I wouldn’t have known to bring these up if not for the smart folks here!!! Thanks.


I insist on paper.
(for real)

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Just a little update.

An hour on the phone with the pharmacy. Seven emails with the CDE. Finally got the Rx right I believe. The key number of units was “max 100u per day” to trigger the insurance to fill for the second box of cartridges.

I loved @Millz supporting reasons! And @Eric and @Thomas were both right about going overboard. And EH pointed out that the pharmacy, and honestly the endo, doesn’t really need reasons (and that I am a bit too verbose at times and people can’t understand what I’m saying amid the chatty politeness) and should fill as written. We should’ve aimed for more at first, I have realized. The waste is a real issue, and sick day/persistent high coverage actually happens here.

Anyhow, I hope by tomorrow I have some insulin in my hot little hands. That would make me happy.

I do think this new endo/CDE is a good team and will be supportive (I did say that about our last ones though, and that’s out the window). :stuck_out_tongue:


So up here in the cold part of the continent, I’ve had both public and private insurance, and I’ve never run into this situation with pharmacies or insurance wanting a limiting prescription like for a number of pills. All my various insulins say “Use as directed” or “As needed.” Is that not allowed in the States? (That said, with public insurance, the number of test strips covered in a year is limited.)


“Use as directed” or “As needed.”
This would provide instructions to the patient and would be OK from that point of view. However it would provide no direction to the pharmacist and so the pharmacist would be unable to fill this.

My prescription is for two vials or three boxes of cartridges or whatever, whenever I need them. No one ever says I’m limited to x units a day.

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My understanding is that insurance companies in the U.S. only want to cover a drug that is distributed in the manner dictated by a doctor’s prescription. Essentially, they don’t want to waste money on drugs that won’t be used or aren’t necessary.

In a way, it is best that the doctor is the one dictating the amount (rather than the pharmacist or insurance company). My doctor is generally very willing to prescribe extra because it is appropriate (as others have said). It may be less appropriate for someone on antibiotics or pain meds though.

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It is two different things.
The one is the directions the doc gives the patient. The pharmacy doesn’t care about that.
The second is the directions the doc gives the pharmacy. This is required to fit certain guidelines of understanding so the pharmacist can fill the prescription.
Often times, the doc is able to satisfy both the pharmacist and the patient with a single directive.

We have found it works best for the doc to say how many (max) units of insulin per day the doc is prescribing which gives the pharmacist a number they can use as to how many units of insulin they are being directed to provide to us. The pharmacist simply calculates the numbers and then rounds up to whatever container size is being provided.

How much insulin is actually used is certainly between us and our Endo. The pharmacist would not get involved in our actual usage.

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I might be a bit off-topic here but the header kind of fits.

As a new “podder” or Omnipod user I just ran into a strange problem with my online pharmacy and possibly my insurance company.
As a quick background: I am switching from Lantus, as the long-term or basal insulin, and a Humalog Kwikpen, to the Omnipod. The Omnipod is filled from the Humalog 100units/ml vials. Since I have to be extra special I would like to use the Omnipod just for my basal insulin line and continue the bolus injections with the Kwikpen. Ok, I don’t have to be special but the Kwikpen is just faster than that Omnipod pos/PDA for the bolus shots.
This requieres that I have to have 2 prescriptions from my Endo for Humalog. The Humalog200 Kwikpen and the Humalog100unit/ml vial for the appropriate units for each of the Humalogs.
The pharmacy has the first “cramp” and brainfreeze since their systems probably just looks at the first letters of the medication and cannot differentiate between the 2. I just got off a conference call with pharmacy and insurer and I hope that I was able to explain the need for 2 different prescription for the same medication with that they are administered differently.
I just hope that this will work out.

To the point of pharmacies not getting involved in the actual usage you have to understand that they are the first barrier against abuse, misuse, overuse, non-use and medication fraud. They will frequently be the enforcer for your Insurance company. In order for us to get ample amounts of life-supporting medication, you will need an Endo that understands real life and what can go wrong. From you dropping the vial and shatter it to a natural disaster and delivery being disrupted. You don’t want to survive that Hurricane and be out of Insulin for 2 weeks and longer. Be sure with your Endo to set the prescribed amounts of units from a minimum to a maximum of units. The pharmacy will do the math from the max amount prescribed for either 30 days or mailorder 90 days. Your insulin will be usually in 100units/ml, kwikpen in 200units/ml. The vial holds 10ml which equals to 1000 units. Now take your daily units and multiply by 30 days. Let’s just estimate you inject 25units daily. 25x30=750 units. With that you would get as the 30 day supply 1 vial of Humalog 100units/ml which is in 10ml vials which is 25% over of what you need or 2 Humalog200 Kwikpens which are 3ml each. This gives you 1,200 units, almost 33% over prescribed amount. Obviously giving you just 1 would leave you short and you die. It is up to you what you do with the extra medication. You can skip one refill every 4 month or give to the needy or just be sure for when that next hurricane strikes.

I’m in Montreal and my endo just writes a prescription for ‘Humalog’. My pharmacy fills my prescription whenever I ask for it and my insurance covers it. I have to say that I feel pretty lucky every time I read posts about insurance/pharmacies in the US.

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