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View Full Version : Insulin terms, units, conversions


k9diabetes
03-28-2008, 10:57 PM
I was reviewing a page on the U40/U100 conversion for posting to the main website and thought this was be a good time to go over the various terms used to describe insulin since the U40/U100 difference and the conversion to use U40 insulin in a U100 syringe has often been a subject of confusion. Eventually, this information will wind up on the main website.

Type of Insulin

Vetsulin = U40 = 40 international units of insulin in 1 mL of solution.

Novolin/Humulin NPH = U100 = 100 international units of insulin in 1 mL of solution

Filling a Syringe

Syringes are matched to the type of insulin used.

When you fill a U40 syringe with a U40 insulin, each mark on the syringe is 1 unit of insulin.

Fill the U40 syringe to the "10" mark with Vetsulin and you are injecting 10 units of insulin contained in 0.25 mLs of "insulin solution", which is insulin plus a diluent.

40u/mL divided by 4 = 10u/0.25mL

When you fill a U100 syringe with a U100 insulin, each mark on the syringe is 1 unit of insulin.

Fill the U100 syringe to the "10" mark with U100 NPH and you are injecting 10 units of insulin contained in 0.1 mLs of "insulin solution", which is insulin plus a diluent.

U100 insulin has less diluent added to it than U40 insulin so the solution is more concentrated.

Talking about Units versus Marks on a Syringe

When you match the insulin type and syringe type (U40 to U40 or U100 to U100), "marks on the syringe" and "units of insulin" or "dose of insulin" are the same thing.

10 marks on the syringe is 10 units of insulin.

It doesn't matter which insulin you are using, only that the syringe type and the insulin type are matched.

When you DO NOT match the insulin type to the syringe, "marks on the syringe" and "units of insulin" or "dose of insulin" ARE NOT THE SAME THING.

This typically comes up because there are times when it is useful to put U40 insulin in a U100 syringe.

When you do make the conversion, you...

Multiply the units of U40 insulin or dose of U40 insulin x 2.5 and

Fill the U100 syringe to mark on the syringe barrel that corresponds to the conversion.

So, for example, if your dog gets 10 units of Vetsulin per injection and you want to give that 10 units of Vetsulin in a U100 syringe, you...

Multiply 10 units x 2.5 = 25.

Then you fill the U100 syringe to the 25 mark to deliver 10 units of insulin.

Why It Matters

It is extremely important for anyone doing this conversion to understand how many "units of insulin" you are giving.

When you fill that U100 syringe to the 25 mark with Vetsulin, you are giving ONLY 10 UNITS of insulin.

Say your dog is rushed to the emergency room or you go to a new vet and they ask you how many units of insulin you are giving?

If you say 25 instead of 10, your dog is in serious jeopardy.

The emergency or new vet may not find out that there is a conversion factor involved.

So it's important to understand the difference between your dog's insulin dose (the number of units) and the strength of the solution of insulin and diluent your dog's insulin is.

While you can't really compare one insulin to another as dogs react to them all differently, a unit of one insulin is equivalent in terms of physical measurements in molecules to a unit of another type of insulin.

Natalie

k9diabetes
03-28-2008, 11:01 PM
Here is a link to a conversion table: http://felinediabetes.com/insulin-conversions.htm

We Hope
04-17-2009, 06:16 AM
When you want to use U 40 insulin in a U 100 syringe you multiply by 2.5, so when you need to use U 100 insulin in a U 40 syringe you divide by 2.5.

Just going to caution here--if you don't get the math right when trying to use U 40 insulin in a U 100 syringe, you risk not giving enough insulin, but when you are using U 100 insulin with a U 40 syringe, you are at risk of giving too much.

Kathy

BestBuddy
04-17-2009, 04:32 PM
I just wanted to add that if you are doing the conversions (I did it for over 6 years without problem) you must remember to tell the vet or anyone else involved in the care of your dog the correct number of insulin units not the marker on the syringe you use.
Jenny