A Question Of Ignorance -- Tuojeo And It's Pen

I am very confused about Tuejeo and its “300 units per ml” concentration. I have always taken Lantus/Humulin NPH and other insulins from a standard syringe and 10 ml vial. Tuejeo comes in a pen. Since it’s supposedly “3 times more concentrated” than Lantus, I would assume that a Type I diabetic who required 60 units/day of Lantus or Humulin NPH would need only 20 units/day of Tuejeo.

Being totally ignorant about how an insulin pen works, I went to my pharmacy and bought some pen needles. I attached one to the Tuejeo pen and set the pen to dispense 20 units. It did not seem to work correctly and only dispensed a much smaller amount… Does the Tuejeo pen automatically compensate for the fact that Tuejeo is 3 times more “potent” than standard Lantus or Humulin NPH? Should I set the Tuejeo pen to dispense 60 units instead of 20?

Frankly, this whole “pen” thing is much more confusing to me than a syringe…

I am not a pen expert.

But based on reading other threads what I recall is that when using specifically a PEN you do not worry about the concentration nor the volume being delivered but rather simply dial the number of UNITS of insulin you want and the pen will deliver the number of UNITS properly.

Hence if you need 60 units of basal, you would dial 60 on the pen and you would get 60 units of insulin.

How Lantus is converted over to Humulin NPH or Tuejeo is I assume a topic entirely by itself and probably not related to the concentration aspect of the question.

This is my understanding, too. Concentrated insulin still delivers the number of units you need, it just does so with less total liquid volume. All units are equal, regardless of the concentration, whether U100, U200, U300 or U500.

The designers of these pens have gone to great lengths to avoid this confusion, If you just focus on the number of insulin units you need then you will be OK. Don’t overthink it.

Check the instructions that came with the pen. I pulled out the instruction sheets for Humalog (Lilly) and Tresiba (Novo) pens I have for backup if I have a problem with my pump. Both state the dose window on the pen shows the number of units dispensed (not volume). In the Tresiba insert, (pens available in both a U-100 version and U-200 versions), it states explicitly that no conversion is needed.

1 Like

My daughter uses that pen. She puts the needle on first then dials the number she needs and it is all dispensed. I did read that if you dial before the needle you will not get what you have dialed in.

Thanks for the helpful advice Bonnie65. Would your daughter use the same dose if she was using Lantus? General question… What difference does it make if there are 300 units per ml or 100 units per ml??? Why should I use Tuejeo rather than Lantus if you don’t take any less?

I’m not @Bonnie65 but please allow me to jump in.

The effective insulin lowering profile is somewhat dose volume dependent. A 50-unit dose of U100 higher-volume insulin will often have a longer onset, peak, and duration than a 50-unit dose of U500 lower-volume insulin. This mechanism of action is labelled pharmacokinetics.

Does that make any sense?

Tuejeo is not stronger, it lasts longer in the body.

@Bonnie65 – Doesn’t Tuojeo also come in a U300 formulation?

This is not correct. The “unit” is a standardized measure of the medicinal value adjusted for the concentration. That’s why it’s measured in units instead of ml.

If you take 10 units of u100, you’d take 10 units of u300 and they’d be the exact same amount of medicine, just in a different amount of liquid.

This is why toujeo is only sold in a pen instead of a vial—- so that someone can’t mess it up and measure it with a u100 syringe. The pen is calibrated for u300. Simply dial up the correct number and inject.

1 Like

Thanks Sam… That’s just the answer I was looking for.

If I use the Tuejeo pen, it is “calibrated” for U300 insulin. Thus, if I used 60 units of Lantus out of a syringe “calibrated” for U100 insulin, I’d use 60 units of Tuejeo from the pen “calibrated” for U300 insulin.

Is that correct?

1 Like

That is exactly correct.

Of course with any new insulin fine tuning of the doses may be needed eventually. But 60u of Lantus u100 is the same amount of insulin as 60u tresiba u300. The latter just happens to be 3x more concentrated, or 1/3 the liquid volume—— but you don’t need to consider any of that it is all designed into the measuring device.

My daughters is the 300u/ml pen and she takes 15 units at night.

When I was diagnosed, there were no pens, and used U40 insulin and U40 syringes. U80 was also available, with corresponding syringes for U80. Then they standardized to U100, and constantly reminded us to double check to match insulin and syringe.
When U200, U300 came out, I think they use pens only to reduce having more syringe sizes.

U40 syringes are still available, primarily for small doses that pets use. For example .5 unit of U100 would be more accurate if dosed as .5 unit of U40, because amount of liquid would be more.

Here’s info that explains for pets.
http://www.petdiabetes.com/pdorg/u40_conv.htm

1 Like

A lot of type 2 patients are highly insulin resistant, which is the overall selling point of toujeo, which is concentrated lantus. With the max solo star pen, you can give up to 160 units per dose…I work with a type 2 diabetic who takes around 100 units per day, usually dialing again while the pen is still in, which is not advised since levemirs max is 60. If you are taking less than 60 units per dose, any long term insulin should be fine…its marketed more for insulin resistant type 2 diabetics. Similar to tresiba 200