Help needed please with Toujeo dosing

N

Noemie&Sushi

Member Since 2026
Hello group,
I am new here. It has been a nightmare trying to figure out the right dose for my newly diabetic cat who has been taking Toujeo now for two months and bouncing all over the place. I do not see any threads about Toujeo here so before I make a spreadsheet with my handwritten data for 7 weeks I just want to know if anyone here will be able to help with this relatively new insulin glargine?
I am at my wits end and hope anyone has experience here. My vet is helping of course but she says Toujeo usually doesn’t bounce like that and I am afraid to give tonight’s dose because he bounced lower this morning than yesterday and afraid he’ll actually bounce too low tomorrow morning if I keep the schedule.
Thank you in advance!
 
We can't help much with Toujeo. It is so concentrated U-300 instead of U-100 like the other glargines, so you can only increase the dose by much larger amounts than we recommend. The only successful Toujeo cases I've seen were on cats that needed really large doses.

Can you tell me why the vet suggested Toujeo? What dose are you giving? If he's going really low then bouncing, he probably needs a lower insulin dose.
 
Wendy&Neko said:
We can't help much with Toujeo. It is so concentrated U-300 instead of U-100 like the other glargines, so you can only increase the dose by much larger amounts than we recommend. The only successful Toujeo cases I've seen were on cats that needed really large doses.

Can you tell me why the vet suggested Toujeo? What dose are you giving? If he's going really low then bouncing, he probably needs a lower insulin dose.
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That is what I was afraid of after going through the posts. It looks like everyone coming to the threads with a Toujeo prescription is convinced to switch to Lantus for fear of the full units and higher concentration. However my vet and another specialist that my cat sees for his urinary problems have both told me Toujeo is actually less potent and needs a higher number of units than Lantus. Yes, it is 3x more concentrated and so less volume is injected, however that makes it harder to absorb and even longer acting in some cases, with an eventually flatter curve and less chance of hypoglycemia. That is the explanation I was given. I will find the reference again but in humans, people switching from Lantus to Toujeo will require 25% more units and in cats my vet told me it can be double so 5 units of Toujeo is more equivalent to 2.5 units of Lantus. Again I would love to have a reference here instead of just my vet but she does seem very knowledgeable. It is not just more concentrated, it is made different and has different potency and so an adjustment of 1un is actually not that big of a deal. Anyway, it seems bouncing is quite common with Lantus too so I will stick with Toujeo for now for Sushi and give it time. He has not gone too low, he just bounces back high everytime he reaches normal levels (5 times now) so we will keep this dose for another week and see if his body will adjust!
If Sushi and I are successful with this, I will be able to help others maybe!
 
Noemie&Sushi said:
That is what I was afraid of after going through the posts. It looks like everyone coming to the threads with a Toujeo prescription is convinced to switch to Lantus for fear of the full units and higher concentration. However my vet and another specialist that my cat sees for his urinary problems have both told me Toujeo is actually less potent and needs a higher number of units than Lantus. Yes, it is 3x more concentrated and so less volume is injected, however that makes it harder to absorb and even longer acting in some cases, with an eventually flatter curve and less chance of hypoglycemia. That is the explanation I was given. I will find the reference again but in humans, people switching from Lantus to Toujeo will require 25% more units and in cats my vet told me it can be double so 5 units of Toujeo is more equivalent to 2.5 units of Lantus. Again I would love to have a reference here instead of just my vet but she does seem very knowledgeable. It is not just more concentrated, it is made different and has different potency and so an adjustment of 1un is actually not that big of a deal. Anyway, it seems bouncing is quite common with Lantus too so I will stick with Toujeo for now for Sushi and give it time. He has not gone too low, he just bounces back high everytime he reaches normal levels (5 times now) so we will keep this dose for another week and see if his body will adjust!
If Sushi and I are successful with this, I will be able to help others maybe!
Click to expand...
I found this:
"The basal insulin glargine U-300 is not currently widely used as a standard first choice option although it has been proven effective at controlling hyperglycemia, reducing daily glycemic variability, and achieving diabetic remission in cats.1 It is more concentrated but less potent than glargine U-100 and therefore should be considered as a separate insulin type and not simply the equivalent of 3 times that of glargine U-100. Because of slowed absorption resulting from the reduced surface area of the injected depot, glargine U-300 exerts a prolonged duration of action possibly allowing for q 24 hr administration in some cats.2 Task force members with experience using “peakless” insulin formulations, such as glargine U-300 and basal insulin degludec, report that many treated cats demonstrate a flat time-action profile more like basal insulin secretion and have used these products for treatment of newly diagnosed diabetics or as an option for difficult-to-regulate cats (see Table 7.1)."
From here: Section 7: Insulin Treatment and Monitoring
 
Noemie&Sushi said:
I will find the reference again but in humans, people switching from Lantus to Toujeo will require 25% more units and in cats my vet told me it can be double so 5 units of Toujeo is more equivalent to 2.5 units of Lantus.
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People and cats handle insulin differently. Lantus is a once a day for humans and twice for cats, but I'd still love to see the reference. In the 5 units of Toujeo vs 2.5 units of Lantus, is that using the Toujeo U-300 pen vs the U-100 Lantus pen?

FWIW, one example I saw of Toujeo in cats was someone who got donated insulin, and hadn't realized that it was Toujeo pen instead of Lantus. Her cat had acromegaly and needed higher doses (thankfully). The cat was mired in high numbers. She started using Toujeo, injecting with the U-100 syringes, same quantity/volume as she had of Lantus. The cat's blood sugar numbers made a complete turn around and she had to reduce the dose. Until she found it was Toujeo. This would not have been good news in a cat not needing higher doses.

As I said above, the biggest issue with Toujeo is that there are not any U-300 syringes, you have to use the pen. Here we make dose changes by 0.25 or 0.5 units at a time using syringes. With Toujeo, you can only change by 1 unit at a time. Cats can be sensitive to very small changes in dose. It's possible the 1 unit increase bypassed a good dose.
 
Yes, for sure the comparison is when using the U300 pen for Toujeo and U100 pen or syringe for Lantus. If you use the U100 syringe to give Toujeo, you are giving way too much. It is a problem that there are no U300 syringes. I was just saying that for some cats, an increase in 1un of Toujeo is actually (according to my vet) more like a 0.5 un increase of Lantus. It might well turnout that in the end I will ask to switch to Lantus because the fine tuning isn`t possible. Sushi went up to 6un twice a day and with a CGM I saw 3 consecutive days of decrease/rebound with the last one from 18 to 4.6. We dialed it back to 5un after that a few days ago and yesterday he went suddenly down to 5.3 from 21 in 3h and then shot back to 21 within the next 3h. Then today no normal ranges at all... My vet said to keep going another week at 5un (2 weeks total after decreasing from 6) to see if the curve will flatten as she expects while his body gets accustomed to lower numbers... We will see! In the meantime his symptoms have gotten way better. He still lacks energy but I am working on my patience! It is all very stressful, and I can`t keep paying for these CGMs, in Canada (Quebec anyway) they are so expensive! I have an alphatrak3 as well and thankfully Sushi is an easy patient ;)
 
Noemie&Sushi said:
It is all very stressful, and I can`t keep paying for these CGMs, in Canada (Quebec anyway) they are so expensive! I have an alphatrak3 as well and thankfully Sushi is an easy patient
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Most of our members in Canada don't use the AT either (strips too expensive), but rather use a human blood glucose meter. Which works perfectly fine, and when I started was all that vets used. The Freestyle Lite is a common model used. It just needs a small blood drop. In BC I often see the tests strips on sale $20 cheaper than other models.
 
Noemie&Sushi said:
I can`t keep paying for these CGMs, in Canada (Quebec anyway) they are so expensive! I have an alphatrak3 as well and thankfully Sushi is an easy patient
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If you have a PC Optimum card, you can use the points to buy Freestyle Lite glucometre strips at your local Pharmaprix.
Also, if you are a senior (or have one handy) you can take advantage of Seniors Day.
Waving from Ontario.
 
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