Hi MIke!
Sorry I missed you yesterday, but you've been in great hands. Fortunately we've got lots of experienced people here who can help teach new members.
I did want to mention a couple of things about night before last.
One - I misread the timing as we were going through the night. I was thinking the drop from 292 to 200 took place in a half hour, but when i looked back to the actual times you were posting, it was over an hour. Any drop over perhaps 50 points per hour can trigger the next bounce - the cat's body is responding to the rapid drop, even if it never gets into low numbers. In any case, even 92 points an hour is fast. I wanted to slow him down although I was thinking the deed was probably already done because he'd dropped from the 473 to the 290 in 2.5 hrs.
I suggested adding the karo on partially because you'd already been giving him low carb and he hadn't seemed to slow much. I also was uber aware that it was 1am for you and you'd expressed how tired you were. Sometimes on here people get so tired that they fall asleep and don't show back up online. I didn't want to have that happen with you and have Webster continue that drop.
There wasn't anything wrong with doing what we did - the point was to stop him dropping and leave him high enough that you could safely sleep - and that's what happened. Sometimes you just need to "abort" a cycle, meaning interrupt how the cycle would play out, for other reasons - like needing to sleep or go out. It's not the usual plan but life happens and you learn to go with it.
Going forward though, the goal is to get any cat into normal numbers and encourage them to stay there. When a cat spends some time in one range, people refer to it as "surfing" which is what Amy was meaning. If you look at some of the subject lines on the main Lantus/Lev TR page, you'll see that some cats are spending hours in the normal range - 50-120. That's the goal of the Tight Regulation Protocol. When they are in those good numbers the pancreas can heal and hopefully, begin putting out insulin again.
So ordinarily we wouldn't give high carbs to a cat until they go under 50 - and then we give just enough to let them go back up above 50 and hopefully, surf along for a while.
I suspect that the AB is contributing to the higher numbers too. If you've only got the 4 doses left, you can just give them and know to watch for his BGs when the antibiotic is done. He may (hopefully) come down at that point.
I meant to get back to you yesterday to go over all of that, but hehehe

i fell asleep on the sofa last night and this is my first chance to get back online.
Did you also buy some gravy high carb cat food while you were out?
Does all of that make sense? Please ask if it doesn't.
by the way, i haven't heard the flea story but an excellent non-toxic treatment is diatomaceous earth. You can buy it in a garden store/plant nursery, it's cheap and you can sprinkle it in your house (carpets, sofa, etc.) and outside. I live in a climate that is ideal for fleas, and the local university entomologist suggested it to me years ago when we had a terrible flea infestation. It's kinda like flour. I put it in a large strainer and then tapped the strainer against my hand for some to sift out. You can leave it for days and then vacuum it up. It is made of crushed diatoms, which if i remember right, is a shelled critter. the substance has sharp edges and it works by cutting through the protective waxy coating on fleas & ants (probably other insects too). The insects then dehydrate and die. You'd want to do it long enough to go through the entire life cycle - maybe more than once. Then you vacuum it up.
I've used it both inside and outside. At one point we had carpenter ants and i started putting a border around the house on the bark so they wouldn't travel from the bark into the house.
It's harmless to people & pets. I've seen it in pet stores but it's hugely expensive there - like $5 for a pint. The bags at the garden store are maybe $15 and you'll have it forever. We also put it on our dog and cats at the time. It still works if it gets wet.