Rebecca --
Have you decided if you're following Tight Regulation (TR) or Start Low Go Slow (SLGS) as your dosing strategy? It makes a difference when it comes to dose reductions. From Marcus' spreadsheet, it doesn't look like you're following TR. (Doses are evaluated every 3 ays/6 cycles vs SLGS when you evaluate the dose weekly when you do a curve.)
Based on the assumption you are using SLGS, because Marcus' dropped below 90, you would reduce the dose to 1.75u tonight.
The pens do not dispense in less than a full unit. Most of us use syringes. Depending on where you live, you may or may not need a prescription for insulin syringes. You want to get U-100 3/10cc syringes with half unit markings. There is information on syringes about halfway down the page
in this sticky note. If it's still early enough to call around, you may want to see if you can get syringes. If you need a prescription, please get one from your vet as soon as you can. If you keep going between 2.0u and 1.0u, you'll end up either over dosing or under dosing your cat.
Regarding the notion that a pen lasts for only 28 days. It's incorrect. I've used a pen for close to 3 months. The manufacturer only tested for that period of time. We also keep the insulin refrigerated which prolongs its life. Given the cost of Lantus, I would not discard a pen after 28 days.
I would also encourage you to always get a before bed test. Without PM tests, you are missing half of your data. You're already starting to see lower numbers at night -- which happens with many kitties. Please do your bets to always get a test so you can turn in for the night knowing that Marcus is in safe numbers.
