? Blood Glucose running higher after new Lantus vial

bobby2478

Member Since 2025
I had a Lantus vial that kept his glucose numbers around the healthy range, but that Lantus had tiny specks/crystals you could see holding it up to light. Since I threw that out and started a brand new Lantus vial his glucose numbers have been much higher. He's a 14 lb cat who was getting 3 units, now with 4.5 units his numbers rarely get below about 300. Could just the change to a new vial have that much of an impact? I'm using the Libre 3 plus.

I've been slowly bumping up his dose from 3 units, to 3.5, to 4, and now to 4.5, sticking with each step for several days to make sure his response isn't unexpected before trying the next increment.
 
Welcome to FDMB
It was a good idea to change to a new vial, but using a new vial, does not make a difference on the BG, I see you are using the Libre, have you checked the sensor?? it can give a false reading if the small needle has moved, as well as it may be wearing out the do last 14 days, but as the days get closer it can falter, do you have a human monitor and strips, it is recommended to have one handy, to re-test in case you feel uncomfortable with either a higher or lower number, I will tag a member that has amazing knowledge on the Libre and can share light on your concerns as well .
Could you have given a fur shot? it has happened to me and all of us, if so, never shoot again if you notice a fur shot, because some insulin might have gone in, and it may cause hypoglycemia
@Staci & Ivy
 
Welcome to FDMB
It was a good idea to change to a new vial, but using a new vial, does not make a difference on the BG, I see you are using the Libre, have you checked the sensor?? it can give a false reading if the small needle has moved, as well as it may be wearing out the do last 14 days, but as the days get closer it can falter, do you have a human monitor and strips, it is recommended to have one handy, to re-test in case you feel uncomfortable with either a higher or lower number, I will tag a member that has amazing knowledge on the Libre and can share light on your concerns as well .
Could you have given a fur shot? it has happened to me and all of us, if so, never shoot again if you notice a fur shot, because some insulin might have gone in, and it may cause hypoglycemia
@Staci & Ivy
I'm getting a new sensor installed today, but he's displaying symptoms consistent with high blood sugar (thirst, lots of urine in the litter box, as well as his usual demeanor as he acts slightly different when his glucose is high) so that leads me to believe it's not just a sensor issue. Considering this has been happening for the past week or so it isn't a single fur shot, and if i truly missed then his numbers would be over 400 instead they mostly remain in the 300-400 range. I never shoot more than once even if a fur shot because to your point there's no way of knowing how much he may have received, so i hold off until next dose.

I'll try to get a manual reading later today as well.

The only other change is he is eating a different wet food, but he was mostly eating that before I started the new Insulin as well so not completely new. Although he's eating a little more of that food to try and get his weight up a bit.
 
What are you feeding? Diabetic cats need to have a diet of wet can or raw food between 0-10% carbs , if you are feeding kibbles this can be the reason and when a dose is given it needs to stay the same for 3 cycles (3 days)?to figure out how the insulin is reacting throughout the cycles in the System, the dose is not changed according to the BG, this can also be the cause
 
When I open a new insulin vial, I keep it in the box, and write the date I opened it, Corky uses ProZinc it needs to be refrigerated and never loose it’s temperature, he uses a dose of 1-50 and the vial, opened last about 3 months, so I have throw away about 1/4 of insulin left, let me find out if Lantus needs refrigeration, I’ll get back with an answer
 
No need for you to check, I already know Lantus needs to be refrigerated and i've been following protocol since he was diagnosed in July. None of this is new to me as i've been giving him insulin 2x daily for the past 5+ months now. My only question was whether the fact his old insulin had crystals in it compared to the new insulin which doesn't could have an effect on his response. At first glance it's almost as though he was more responsive to the "old" insulin with crystals suspended in solution compared to the brand new insulin (same prescription, just a new vial).
 
I'm not familiar with how lantus is meant to look. But we all know medications occasionally get recalled due to manufacturing issues, insulin is also reasonably delicate freezing/overheating too much agitation can damage it. So I would say it's possible there is something not right about your new vial. The timing of the need for multiple dose increases is suspect, but that doesn't mean it is definitely the new insulin.

Where did you get it from? Lantus is a human insulin so maybe a pharmacy? It might be worth giving them a call and asking if they've had anyone else complain about insulin they've recently picked up. If you are able to get a new script and pick up from somewhere else that might be worth trying but be very careful with dosing if you do get a new vial.
 
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No need for you to check, I already know Lantus needs to be refrigerated and i've been following protocol since he was diagnosed in July. None of this is new to me as i've been giving him insulin 2x daily for the past 5+ months now. My only question was whether the fact his old insulin had crystals in it compared to the new insulin which doesn't could have an effect on his response. At first glance it's almost as though he was more responsive to the "old" insulin with crystals suspended in solution compared to the brand new insulin (same prescription, just a new vial).
if the bottom of the vial is crystalized or very cloudy, it is a bad vial and in that case you are correct that insulin is bad, and it does loses its effect if the vial is recently purchased i assume you can take it back to the pharmacy, make sure that when you get a new one, open the box in front of the person that gives it to you, I am sure you know not to agitate the content, but gently turn the content softly, I was told that insulin is very sensitive, and can corrupt if shaken hard in the vial, so I learned to just turn it from side to side slowly 5 times, in 4 years I did have a newly opened vial that corrupted after just four doses extracted, and you should take it to the pharmacy so they can see it, I hope everything turns out
 
I'm not familiar with how lantus is meant to look. But we all know medications occasionally get recalled due to manufacturing issues, insulin is also reasonably delicate freezing/overheating too much agitation can damage it. So I would say it's possible there is something not right about your new vial. The timing of the need for multiple dose increases is suspect, but that doesn't mean it is definitely the new insulin.

Where did you get it from? Lantus is a human insulin so maybe a pharmacy? It might be worth giving them a call and asking if they've had anyone else complain about insulin they've recently picked up. If you are able to get a new script and pick up from somewhere else that might be worth trying but be very careful with dosing if you do get a new vial.
Unopened Lantus insulin should be refrigerated once you start using it, but you know this, but once opened, it can be kept at room temperature for up to 28 days.
 
Looks like you are home testing his blood sugars? If so, would it be possible to enter the data in our spreadsheet format? Maybe just the week before you switched vials and the time since then. I can think of scenarios where the higher numbers are as a result of the new insulin working much better than the old vial was. Giving us a look at his blood sugar data will help diagnose what is happening. Instructions on how to set up the spreadsheet are in this post. New? How You Can Help Us Help You!

Let us know if you need help setting up the spreadsheet.

Ignore the above on keeping the Lantus vial out of the fridge once opened. You are correct that it should be kept in the fridge at all times, except when actively using it. Only humans, with much larger doses, keep Lantus out of the fridge as they will use it up before the 28 days.
 
Unopened Lantus insulin should be refrigerated once you start using it, but you know this, but once opened, it can be kept at room temperature for up to 28 days.
I’m sorry if this information was misleading, I looked it up before posting it, I copied/pasted that part of the article about Lantus
 
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