Levemir is a depot insulin. This means that some of it gets stored in the subcutaneous fat and gets slowly released into the bloodstream. Insulin is not a drug, it's a hormone, and its action happens in waves. If you change the dose all the time, the depot is uneven and you don't know how Raymond James is doing on the dose. That's why holding the dose for 7 days (if you are following SLGS) or 3-5 days (if you are following TR) would be helpful rather than changing it every time you see a number that's lower than what you are used to.
From the
What is the Insulin Depot sticky at the top of the forum regarding Levemir:
Have you ever wondered why, when you are giving the same amount of insulin every time, the response is different in each cycle? Sometimes the numbers go up for the whole cycle, sometimes they go down, sometimes they stay flat, and sometimes they actually “curve.” The answer often lies in the depot. Did you skip a shot or give a partial shot at some time in the past few days? That can result in higher numbers for several days as the depot replenishes some of its lost stores. Did you increase the dose? This can result in a change in the size of the depot and can lead to a temporary adjustment in the amount of insulin available for use. Did you decrease the dose recently? A dose reduction will usually result in a need for less stored insulin. The excess may be released into the bloodstream faster than usual, especially if several dose reductions are done back-to-back.
Absorption
Gradel and colleagues (2018) note that absorption can be affected by the composition of the tissue layers, the physical-chemical composition of the insulin along with the type of insulin, the concentration and volume (i.e., dose) of the insulin, and insulin injection technique and site. Not all of these factors are easily controlled which is why every insulin dose may not produce identical results. To further add to the challenge, it is difficult to estimate how long it takes both for the “depot” to form at the outset but also how long it will take for a dose change to stabilize.
Practical experience on FDMB shows that as a generalization, the depot can affect up to 6 cycles. The time tends to be less when a cat is on a smaller dose, and more when a cat is on a larger dose. Other factors can apply as well, but using the generalization of 6 cycles is a good starting point until you have learned your particular cat's patterns.
Now you are probably asking "How on earth can I use this information to understand my cat?"
Try to look at your spreadsheet not in 12-hour cycles, but in “waves” of action over a period of several days. Look for overall trends more than individual numbers. If something jumps out and doesn’t seem to make sense, go back 2-3 days and think about any changes that might have occurred in insulin, timing, exercise, health, food, etc. If the big picture is making sense but you see one cycle that doesn’t fit, then keep that 20-50% variation in mind and just wait it out.
