Toujeo insulin unit size

[Yvonne & Simon]

Hi all
Further to all the helpful suggestions you have provided me regarding the use of Toujeo insulin in my cat Simon.

Just to recap. I have been given a pen of Toujeo insulin which can only be administered in 1 unit increments.

It is a more concentrated insulin which contains 300 U/ml vs Lantus which provides 100 U/ml.

However the confounding thing is that it is dosed at the same number of units as Lantus. Eg if a person (or animal) was getting 2 U of Lantus, they would be switched over to 2 U of Toujeo, with the adage that it is a concentrated thus lower volume insulin.

The kind folks on here have expressed concern that there is no way to give part doses of the Toujeo with the pen. So suggestions have been made to draw out the insulin out of the pen, using a 3/10 ml/cc syringe with the half unit markings on it.

My gut feeling told me there was something wrong with this, and my suspicion was that one unit of Lantus and one unit of Toujeo are not the same size (volume).

I have taken a photo of my little experiment but unfortunately cannot seem to find a way to upload this.

However what I did was drop 1, 2, and 3 unit increments of both regular 100U/ml insulin vs the Toujeo 300U/ml insulin. And compare them against each other.
The equivalent unit doses of the Toujeo are significantly smaller in size than the Lantus drops. Thus the unit sizes between the two are NOT equivalent!

In other words, a regular insulin 100/ml syringe (say in the 3/10ml/cc) size CANNOT be used to inject Toujeo!

I decided to make a specific posting about this, just in case this comes up again, as this is a real safety issue.

thanks everyone!

 

[Yvonne & Simon]

This photo shows the droplet sizes of a 100U/ml insulin on the left side and Toujeo insulin on the right side, in 1, 2, and 3 unit increments.

As you can see, they are not the same sizes. In other words, a regular syringe cannot be used to give part doses of Toujeo.

 

[Wendy&Neko]

Correct - you cannot use syringes to inject Tujeo. It must be done with U-300 syringes, but they don't exist. So you are stuck with the pen as long as you use Toujeo.