Lantus pen technical discussion regarding needle/syringe/refrigeration

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Steph & Quintus & L & O

Member Since 2017
I have a Lantus pen. [note: yes I know people here don't like the pen needle. bear with me]

I used a syringe on it a few times to give a dose with a half-unit. Now I'm back on a full unit, and wanted to use the pen needle again.

I have been careful not to get air bubbles in the reservoir.

I stuck a needle on the pen, turned the wheel to prime it, and... nothing came out. Tried again, still nothing.

A bit later, I had a brainwave: since the way the pen expels its doses when using the needle is by applying pressure to the liquid, if I have removed anywhere between 8-10 units with my needle shots, maybe I need to "dial back up" to those numbers?

So I turned the wheel a bit more, a few times, and lo and behold, insulin started coming out of the needle.

I did a check with 1ui and 2ui as I've already drawn "blanks" for those values and have an eyeball sense of how many drops should come out. Seems good.

Questions:
1) does my analysis make sense?
2) anybody else been through this -- drawing insulin with syringe, then wanting to go back to the needle, and having to "catch up" with the dial?
 
I have no experience using the pen and its needle. From a measurement point of view, though, I prefer consistency of method (science geek here!) and I would stick to the syringe method for all doses instead of going back and forth. You'll need the syringe eventually to draw up fractional doses in the quarter unit range.
 
I don't have experience with pen needles either, but are you keeping it room temp or in the fridge? I have read that keeping it in the fridge messes with the dial mechanism. I think you are also supposed to prime them? If that's the case, it should give you the dose you are looking for after the prime? Sorry I'm not much help, never used the pen needle before, but I know you're still gathering supplies and all that, so using what you have on hand while you're on a whole number dose makes perfect sense. :)
 
@Stacy & Asia is right. Refrigerated pens will likely not dispense the dialed amount because the cold affects the mechanism.

Otherwise, your analysis is correct. When used as directed, the dial and button operate a little plunger at the end of a screw that pushed the stopper down to expel insulin in the desired amount. If you've been withdrawing insulin with a syringe, the negative pressure pulls the stopper down creating a gap between the stopper and the screw mechanism. So you'll need to dial up a few doses to push the screw down until it makes contact with the stopper once again. Then it should work as it normally does.
 
Refrigerated pens will likely not dispense the dialed amount because the cold affects the mechanism.

Do we have data on this? Most instructions I've found regarding Lantus pens and pets recommend keeping them in the fridge as we use small doses and therefore require the pen to last longer.

Is this amount differential something that we hypothesise based on our knowledge of the mechanism and physics, or do we have experimental data to back it up?
 
Do we have data on this? Most instructions I've found regarding Lantus pens and pets recommend keeping them in the fridge as we use small doses and therefore require the pen to last longer.

Is this amount differential something that we hypothesise based on our knowledge of the mechanism and physics, or do we have experimental data to back it up?

So the manufacturer recommends the pens are only good for 28 days and must be stored at room temperature when in use, these instructions are for people, however, it's off label for cats and the insulin degrades less when refrigerated (although other factors can contribute to it breaking down refrigerated or not). I believe it may be in the insert for the pens that the cold affects the dial mechanism? If not, I'm positive I read about it in a medical journal article, I'll see if I can dig it up for you.
 
@Stephanie & Quintus - You know, I'm going to call myself out on this one because I'm echoing what I've always read without independent verification. If there's a study to show temperature-dependent dispensing, I didn't find it in my admittedly brief search. Perhaps it hasn't been studies. Perhaps it's related to the general wisdom that injecting cold insulin is uncomfortable. Perhaps it's to dissuade people from using the dial-a-dose because dose adjustments less than 1 unit are not possible. I don't know at the moment...
 
My vet instructions were to leave the pen in the fridge and we started on the pen needle as well.

That said, once I started drawing with a syringe I never went back. Found it easier to give the shot in my tiny little hand.
 
Humans having the same questions: http://www.diabetes.co.uk/forum/threads/lantus-pen-storage.4253/ (no real resolution, but one of the humans has been using his out of the fridge to no ill effect)

I guess, as with everything, what's important is consistency. If you shoot out of the fridge, shoot out of the fridge. If you don't, don't. Mixing both techniques could maybe end up giving you dose variations (or not). If you use the same technique all the time, chances you're fine.
 
That said, once I started drawing with a syringe I never went back. Found it easier to give the shot in my tiny little hand.

Maybe I need to find my reading glasses, but with bleary 6am eyes and bad lighting (well, indoor lighting) I find it stressful to find the right mark on the syringe. The pen is more "set and forget", even though I do prefer the rapid injection the syringe allows. Quintus isn't always happy to have me counting crocodiles with the pen stuck in his scruff.
 
Maybe I need to find my reading glasses, but with bleary 6am eyes and bad lighting (well, indoor lighting) I find it stressful to find the right mark on the syringe. The pen is more "set and forget", even though I do prefer the rapid injection the syringe allows. Quintus isn't always happy to have me counting crocodiles with the pen stuck in his scruff.
I actually sit at my desk with a bright lamp on my work area when I'm prepping a syringe. I hold it over a white surface to boost the contrast between the background and the lines. I also use reading glasses in a higher magnification than I need for reading.
 
I thought it was in one of these 2 articles I will link here, but I can't seem to track it down. It is possible I read it here after reading one of these articles and I made the association in my head that way. :p I do most of my diabetes research on human diabetes, specifically with children (because they are closest to the doses most of our cats are using). Consistent small doses is just as much of a problem for kids, insulin pumps seem to be the most accurate answer for them, and not a good option for our cats.

It's hard to research feline diabetes because the best stuff so far really appears to be the TR stuff, not a lot is being studied in cats that I can find, outside of high dose conditions like acro. I guess it's too boring? :rolleyes: Not enough money in it, who knows? Anyway, you can glean a lot of info from the human journal articles and it may or may not always apply to cats, but TR for cats was developed from a similar human study where, get this, the protocol was such an overwhelming success, they switched the control group to using it before the study was even over! :eek:

Also, search on the forum for Degludec, I made a post about it and linked an article there, it's a new long acting gentle insulin for humans (42 hours, supposedly) that shows promise for being a once a day dose for cats but it's so new, I can't find much info on cats using it yet.

Anyhow, like me, you seem to enjoy a good nerdy journal article, so you can add these to your collection:

Shelf life of insulin: http://care.diabetesjournals.org/content/26/9/2665

Accuracy of low doses: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1717622/pdf/v079p00059.pdf

An interesting note on this study, dial doses are more accurate than syringe doses, and syringe doses drawn by parents are more accurate than drawn by nurses ;)
 
I couldn't see the markings on the syringes properly myself, so I bought a magnifying headset on ebay that works brilliantly, even when the batteries for the lights fail.

Which syringes are you using? If you're using the BD 1/2 unit ones from hyperdrug.uk, then later on, when you're doing really low doses, you might find that you'll get more precise measurements by using the insulin ruler or calipers. I've only used the insulin ruler so far, but many prefer calipers.

I'm attaching an article that you might find interesting if you haven't come across it yet: Management of diabetic cats. The link to this is in one of the stickies, and I found this article very helpful. You can also find the tight regulation protocol and management of diabetic cats presented in a different format on Tilly's page (in German and English). The link I put there goes to the page that has lists of different articles that I think you might find interesting, given your question early re: scientific reports and data. I assume you're doing the Start low go slow protocol (SLGS) as you're still on high-cal dry food, is that right?

I'm an info junkie, so apologies for inundating you with information!
 

Attachments

I couldn't see the markings on the syringes properly myself, so I bought a magnifying headset on ebay that works brilliantly, even when the batteries for the lights fail.

Not to hijack the thread, but can you imagine what new people here must think when they see all these things? :joyful:

We should prepackage a crazy cat people FD kit and give proceeds to DCIN. It would contain: magnifying headset, calipers, a light box, an automatic feeder, diabetic supplies organizer, a few cans of FF HC, honey, home enema kit for cats, SEB, AVJ, a sock full of rice, a kitchen scale, ear salve or neosporin, ketostix and a long spoon to catch pee, a monitor and some strips and a one size fits all pair of patience pants. Am I missing anything? :joyful::joyful::joyful:
 
Not to hijack the thread, but can you imagine what new people here must think when they see all these things? :joyful:

We should prepackage a crazy cat people FD kit and give proceeds to DCIN. It would contain: magnifying headset, calipers, a light box, an automatic feeder, diabetic supplies organizer, a few cans of FF HC, honey, home enema kit for cats, SEB, AVJ, a sock full of rice, a kitchen scale, ear salve or neosporin, ketostix and a long spoon to catch pee, a monitor and some strips and a one size fits all pair of patience pants. Am I missing anything? :joyful::joyful::joyful:
Oh that made me laugh!!! Love it. Could you pop over and see Silver’s condo? Needing input. Thx.
 
Not to hijack the thread, but can you imagine what new people here must think when they see all these things? :joyful:

We should prepackage a crazy cat people FD kit and give proceeds to DCIN. It would contain: magnifying headset, calipers, a light box, an automatic feeder, diabetic supplies organizer, a few cans of FF HC, honey, home enema kit for cats, SEB, AVJ, a sock full of rice, a kitchen scale, ear salve or neosporin, ketostix and a long spoon to catch pee, a monitor and some strips and a one size fits all pair of patience pants. Am I missing anything? :joyful::joyful::joyful:
:D:D:D:D!!!!
 
We should prepackage a crazy cat people FD kit and give proceeds to DCIN. It would contain: magnifying headset, calipers, a light box, an automatic feeder, diabetic supplies organizer, a few cans of FF HC, honey, home enema kit for cats, SEB, AVJ, a sock full of rice, a kitchen scale, ear salve or neosporin, ketostix and a long spoon to catch pee, a monitor and some strips and a one size fits all pair of patience pants. Am I missing anything?

I wish this were a thing. It should be given as a matter of course to anyone who gets a diabetes diagnosis from their vet.
 
Not to hijack the thread, but can you imagine what new people here must think when they see all these things? :joyful:

We should prepackage a crazy cat people FD kit and give proceeds to DCIN. It would contain: magnifying headset, calipers, a light box, an automatic feeder, diabetic supplies organizer, a few cans of FF HC, honey, home enema kit for cats, SEB, AVJ, a sock full of rice, a kitchen scale, ear salve or neosporin, ketostix and a long spoon to catch pee, a monitor and some strips and a one size fits all pair of patience pants. Am I missing anything? :joyful::joyful::joyful:
Oh, I had a burst out loud laugh when I read this, Stacy! I've got several pairs of patience pants, myself, not that they do me much good...

Yes, you left out some very important supplies: a bubble wrap jacket and/or washable shower curtains for cats who sleep with you but suffer on occasion from leaky poo...

I actually now have a bookshelf dedicated to different carb cat foods and a stackable drawer system for other supplies and meds...

Pill cutter... Syringes for liquid meds... A pet/baby scale... dedicated ice cube trays for freezing pumpkin and leftover cat food...dedicated pan and washcloth for those poo-related clean-ups (you can see I'm focused on poo-issues right now...). .. sharpie for labelling when a cat food can was opened...oh, the list goes on and on and on! :-)
 
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