Once a Day (SID) vs. Twice a Day (BID) Insulin Dosing

When Sassy was first diagnosed on 16 September 2001, our Veterinarian put him on Idexx PZI (now PZI Vet) and we were hoping one shot of insulin a day would work for him. We started at 1 unit, once a day and got up to 3 units fairly quickly (within 4 weeks). Unfortunately, he was not showing any signs that the insulin was working well for him. He was still lethargic, flooded the litterbox, drank like a fish, and his hind legs were weak.

After some discussion with our Vet, we decided to split his single 3 unit morning dose, and put him on 1.5 units twice a day, am and pm. The results were dramatic! Sassy's symptoms began to disappear and his energy level increased! We made no other changes to his routine at the time; same food, same level of exercise, no infections, no other medications were changed...

The curve in blue represents Sassy's blood glucose numbers while on 3 units Idexx PZI once a day. He started high, and ended high, with approximately a 300 point drop during the day. No wonder he felt lousy!

The curves in black and red represent his blood glucose numbers after splitting his dose in half and giving him his insulin twice a day. Because PZI is so long lasting, we had some overlap and so, went from large swings in blood sugar levels, to a nice, almost flat curve.