My doctor gave me some U200 samples to use up at 24 units per day and gave me a prescription for U100 to fill. I have one month filled and requested the script be written for U200 but have 5 pens of the U100 to use up. Question is do I still use 24 units of the U100 or do I double it?
Thanks
The pens are sort of “self-adjusted” in that they deliver the correct number of units based on the dial.
If you dial 24 units on the U200 pen, you get 24 units.
If you dial 24 units on the U100 pen, you get 24 units.
With U200, you only need half the volume of insulin as with U100 for the same number of units, hence the ability of the U200 pen to provide about twice the units of insulin as the U100 pen, over the life of the pen.
The mechanical “clicking” and delivery mechanism for both pens in the same, hence the ability of the U100 pen to provide any integer number of units (one “click” equals one unit), whereas the U200 pen does even-numbered doses only (one click equals two units).
If you stick to the numbers on the pen dial, you’ll get the units of insulin desired with either pen.
Thanks, I was really confused as to how to dose those pens and you explained it perfectly Truenorth. 
Please clarify: I asked my doc to try the U200 pen. He phoned to make sure I understand that I will inject 1/2 the dose as the U100 pen. So, if I’m injecting 16 units with the U100 pen, I will go to only 8 units with the U200?
I have been using the U200 pens for awhile now. The dosage is the same 16 units on the U100 or the U200 the pen makes the correction on how much to give you. The U100 pen goes in 1 unit increments and the U200 goes in 2 unit increments so you cant take say 7 units on the U 200.
Hope that helps you
The pen markings are “units,” inject a unit and it is the same whethet U100 or U200. The U200 dose will be half the volume of the U100 dose because it is twice as potent.