May 22, 2008

The Great Vial Experiment

I use very small doses of basal insulin. No more than 2.5 units a day.

But though I've been able to make an insulin pen last long enough to use up every drop of insulin in it, my experience with vials over the past several years has been that the insulin in them always goes bad, no matter what I do to try to keep them alive.

I've tried all of the following: Alway using a new syringe, wiping the top with alcohol, and refrigerating the vial with a thermometer near it to make sure it isn't getting too cold. It doesn't matter. Insulin from the vial always starts to weaken after about six weeks and my blood sugars start creeping up. If I get a new vial, it's immediately very clear how weak my old vial was and if my doses have been creeping up I can have an interesting day the first time I use the new vial.

Pens don't do this even when I reuse pen needles, and my guess is it has something to do with the pressure inside the pen which pushes anything in the needle out before it can enter the insulin container and contaminate it.

Whatever the explanation, my current insurer charges the top copay--$50--for a vial of the kinds of insulin I'm using and won't cover pens without a long and complicated appeal put in by my endocrinologist. I don't like to use pens for the basal anyway, as I use fractional doses and I don't trust the pen to dispense 1 unit accurately. So when I bought my latest expensive vial of Levemir, I decided to try an experiment to see if I could keep the insulin in the vial alive for a longer time.

What I did was mail order some sterile 10 ml vials and transfer 100 units of insulin into the new sterile vial. I'm going to draw the insulin from that sterile vial, not the manufacturer's vial and thus cut way down on the number of times I introduce a needle into the main vial. Hopefully this means I'll be able to use all of those 1,0000 units instead of only 150 or so.

Another benefit of this approach compared to pens is that I won't be wasting the many air shots I have to waste when I use pens. The air shots can use up even more insulin than my basal shots. The convenience of the pen is a huge issue with post-meal insulin, but not for basal.

I'll be reporting back in a few months about whether this strategy is effective. If any of you who use tiny doses have any other suggestions about how to keep insulin in vials alive. Let me know.

UPDATE: 5/24/08

The insulin in the mail order vial is still working as it should. The only problem I've run into is that my syringes are dulling out much faster than they do I've been reusing them with a manufacturer's pen. This is probably because the rubber seal on the mail order vial is made out of a cheaper material.

The result is that the shots will hurt and bruise if I don't change the needle after no more than 2 shots.

NOTE: I have tried not reusing needles and reusing needles and have not seen any difference in how well my insulin holds up. When I reuse a syringe I do not inject air into the vial and I carefully expel any insulin left in the needle squirt-gun style after each use. Periodically I bleed the air out of the syringe by inserting a new needle with the plunger removed. This is the procedure described in the book, Dr. Bernstein's Diabetes Solution.


Anonymous said...

my suspician from what little I know about sterile procedures is that the repeated air we inject into the vial to maintain atmospheric (sp) pressure will introduce microorganisms into the vial. I do seem to get two months out of my Regular Insulin, which I use to cover occasional highs and pre-exercise. RobLL

Jenny said...


That makes a lot of sense! When we use pens we don't inject air.

So perhaps the best approach would be to remove insulin from the main vial with a syringe and not inject air, though I think that eventually the vacuum might build up and make it hard to withdraw any more.

Anonymous said...

Just a thought, can insulin or any of the other ingredients, oxidise? If so, that would point also to air as the culprit


kindletheflame said...

while I don't take small doses (I take 45-55 units a day, type 1 on a pump), I have noticed that pen cartridges work way better for me than regular vials. Usually I fill my pump from pen cartridges, but the few times I've used vials I've noticed that near the end my blood sugars run way higher. Usually I end up adjusting basal rates and boluses accordingly with little success, and then end up crashing low when I give up and switch to some new insulin. I don't notice this happening with the pen cartridges. I thought I was crazy, but other people I know have experienced similar things. So I definitely think there's something to what you've written about.

Anonymous said...

Heaven forbid that we ask the insulin cartel to do anything patient-friendly, like offer a 'vial' and a 'mini-vial' or 'low-dose vial'. I imagine the expense would be just too great for them to shoulder.


Jenny said...

The insulin companies offer cartridges and pens with smaller doses, but only in packs of 5 and at a price that makes them much more expensive per prescription than the vials.

Which is why my insurance won't pay for them.

But a 5 pack of cartridges or pens is currently paid for out of pocket is cheaper for me than the vial with the $50 copay, assuming that the cartridges last 5 months in the fridge.

Custom Pens said...

I am taking a few doses of basal insulin. As for adjusting basal insulin levels during exercise I am still working on this. I am a dance and i am dancing over 12 hours daily. I can't cut down due to the fact that it is a certain program for professional dancers. For non-diabetics basal insulin is the background insulin that the pump puts out throughout the day. Because i was told that insulin sensitivity increases with exercise. Do you have any advice as to what i should do?

Thanks in advance,

Jenny said...


Sounds like you need to find a doctor who will work with you to get your doses set right. This is the job of an endocrinologist. Some are better than others. Sounds like you need to find a new one.

If you can't afford to see an endo, you need to visit some of the diabetes discussion areas frequented by people with Type 1 who might be able to point you to some resources or advice.

You might also want to read "Think Like a Pancreas" or "Using Insulin" which are some books some people have found helpful. Your public library should have a copy or should be willing to order one for you. Ask the reference librarian.