Hi Becky,
Prozinc works the same way as Humulin in one respect. It is a "one-shot" insulin. That means you give a dose, and when it wears off 10 hours or so later, it's "done and gone".
The big difference between the two is that Prozinc takes a little longer to start working (onset), and it doesn't work as quickly. It also has a longer duration than Humulin.
Humulin starts working, I think, within an hour, but it only lasts 4-6 hours.
Prozinc kicks in about 2-3 hours after the shot, and continues working for 9-10 hours.
An insulin like Humulin works better in dogs than cats. Cats process insulin twice as fast as dogs or humans do.
Prozinc should be shot on a 12 hour schedule. It reaches peak effeciency about 6 hours after the shot. That is referred to as the "nadir". When you are hometesting at first you want to make sure and ALWAYS test prior to giving a shot, and with Prozinc you should try to get at least one more reading between shots, preferably around the "nadir". When you make adjustments to the dosage, you would use the Pre-shot numbers as well as the nadir number to determine the dose. Dose adjustments should be made in small increments, no more than .25 units at a time. Once you decide on a dose, you should try to stay at that same dose for at least 3-4 days so that you can see what sort of numbers you get. The "normal" starting dose is 1 unit, twice a day. (1u BID)
One thing you will see a lot here is the acronym "ECID", which means "every cat is different". You asked about my take and what to watch out for, but all I can say is that some kitties respond well to it, and others are better suited to one of the "L" type insulins, which would be Lantus and Levemir, which work a lot differently than either Humulin or Prozinc. I don't know enough about them to evaluate which is "better". There are a couple of kitties here that used to be on Lantus and were switched to Prozinc/PZI and a couple of people who were using Prozinc recently swtiched to Lantus. So there are a few people who post here that can tell you their opinions on both types.
Carl
