U40 insulin doses

I’m trying to work something out with a friend. She uses a U40 insulin. If a U40 insulin contains 40 particles of insulin, tell me if this makes sense? 4 units of u40 would be 160 particles. If that was a U100 insulin, it sounds like that would be 1.6 units, so not really a high dose. All things considered and differences in insulin types considered, does that logic make any sense? Basically many of us think of 4 units as a high dose, but is it really in a U40 insulin? She uses Vetsulin.

 

There's a conversion chart for using a U40 insulin with a U100 syringe

You're doing the math backwards (although I know it looks like it should be "your way")

But you also can't compare it like that.....Just because 4U of Vetsulin would measure as 10U on a U100 syringe, it's not like saying it's the same as 10U.

U100 syringes have a much smaller barrel than U40 syringes so while it LOOKS like more, it's really not

 

I'm not entirely sure what you're asking but I think you might be a little confused. And this can be confusing!

4 units is 4 units if you use the corresponding syringe. No conversion necessary.

What I mean by that is:
- 4 units of a U-40 insulin (such as Vetsulin) in a U-40 syringe is 4 units.

- 4 units of a u-100 insulin (such as Lantus, Levemir, Novolin, etc) in a u-100 syringe is 4 units.

The only time you need to do a conversion is if you use mismatched syringes (for example, a U-40 insulin with U-100 syringes).

The difference between a u-40 and a u-100 insulin is strength. To use your words, the difference would be the number of insulin particles in 1 ml of liquid.

So if your friend is using Vetsulin with u-100 syringes and drawing to the "4" mark, she is indeed giving 1.6 actual units of Vetsulin. If however she is drawing to the 4 mark of a u-40 syringe, then she's giving 4 units of Vetsulin.

You always want to refer to the actual number of units given, NOT where you draw to on the syringe.

 

Great post, @JL and Chip .

 

Thank you! So the original thought that starting at 8 units and even lowering to 4 units was probably too high of a starting dose. Since I’m not familiar with U40s, just wanted to know if the same thought process applied to that type of insulin. Now to ask her if the vet explained why they started at that dose. I sure like Lantus better.

 

4U is a crazy starting dose of ANY insulin....8U is absolutely insane.

I'd say her vet doesn't know the first thing about treating feline diabetes

 

I was talking to my friend and the picture suddenly became much clearer. She just remembered that her vet was out of the red cap U40 syringes so gave her some orange cap U100 syringes to use until he gets more in this week. So, she's filling a U40 insulin to 4U in a U100 syringe. So according to the chart, that's 1.6 U of the U40 insulin. Whew! Got that? I asked her to tell me how much he tells her to fill the red U40 syringe when she gets it on Monday.