Actually I wanted to add that a cat can get hepatic lipidosis by not eating for 24 hours....it is crucial they eat something. more info here..
http://www.felinediabetes.com/hepatic.htm
That and the concern that ketones will show up which can lead to diabetic keto acidosis ( DKA )really quickly, are all really good reasons to talk to your vet if your kitty is not eating.
I am wondering, with the lower levels you are seeing at what is quite a small starting dose, if perhaps you have a transient diabetic on your hands brought about by perhaps the initlal problem that you are giving antibiotics for.
Can you tell us a bit about why you went to the vet originally, what is being treated and what the blood glucose levels were at time of diagnosis?
We see this quite a bit here...a cat gets something like a urinary tract infection.
This causes stress on the body which in turn raises the blood glucose and the vet sees worrying levels and offers insulin and antibiotics.
Meanwhile, once the antibiotics start to work and clears up the UTI -the blood glucose levels lower once more and the cat has a couple of close calls hypo wise while the owner catches up to the idea that the kitty is not needing as much insulin anymore and reduces dose, hopefully to not needing a dose anymore.
Another thing that causes illness and diabetes, is chronic pancreatitis- a great info page here...
http://www.felinediabetes.com/phorum5/r ... 722,876722
Going off food, is often seen in conjunction with a pancreatitis flare up
My kitty had a version of this.
The worry I have for you is the lack of eating, and the antibiotics treating an infection? this opens the possibility for this to lead to ketones.
Are you testing for them? it is quite an easy pee stick test...here is some more info about that as well..
http://felinediabetes.com/ketones.htm
I really recommend reading as much of that as possible and ask lots of questions. We all will try to help sort through it to find the issues for your kitty.
how is he feeling/eating etc today?
Did you get any sleep at all? ((hugs))
Kimmee