Hi Jieun Lee and Welcome to the FDMB!!
I'm Chris Ronkoski from the Facebook group and I'm happy to see you made it over here! Here's some info from your Facebook post that I'm going to refer to:
Sep 2: morning 431 / evening 83
Sep 3: morning 428 / evening 111
Sep 4: morning 450 / evening 140 (right after eating)
So, past 3 days I gave him a shot (2units) in the morning and no shot in the evening.
But he cries all night for past 2days and now I just felt he is not much active like in the afternoon so checked his BG and it was 422. I feel something wrong here...
What I think might be going on is that Charls dose is too high. 2U is high starting dose...most of our cats we start at .5-1U
When you give the 2 units in the morning, by the PM his blood glucose is down but then since you skip the PM dose, it goes right back up again. Lantus needs to be given every 12 hours, so it's important to find a dose that's safe to give him
both in the morning and night
Lantus dosing is based on how LOW it takes them, not the tests done before the shot (the Pre-shot tests), so it's important for you to start getting some tests in mid-cycle so we can see how he's doing. Somewhere between 5 and 7 hours after the shot in the morning and a test "before bed" at night to make sure he's going to be safe overnight is what we'd like to see for now.
The spreadsheet that's been mentioned above is a very valuable tool that we use here a lot. Please don't be afraid to ask for help if you have trouble with it!!
As for the crying and change in activity level....when we first start treatment and our kitties blood glucose is all over the place, it can cause some changes in their behavior....If you think about it, if your blood glucose was going from 400 to 100 and back again every day, you'd feel pretty awful too! With some time though (and help from the wonderful people here) we'll try to get him evened out and he should start to feel much better...and you should even see him doing things he hasn't done for a long time, like playing old games he used to play! Once they really start to feel better, it's amazing how much difference you can see in them!
If the crying continues, I'd be sure to test when he's doing in (to make sure he's not too low and is crying for food) but if he's showing any signs of distress, it's probably a good idea to get him checked over by the vet. Also make sure the crying doesn't have anything to do with when he's peeing or pooping.
Again, welcome and please ask all the questions you want! We're all here to help you and your "extra sweet" Charls!