Many Lantus and Levemir users in this forum have been successful following a somewhat modified version of this Tight Regulation Protocol for the last few years. These "general" guidelines are based on anecdotal evidence and personal experiences of laypersons frequenting the forum.
"General" Guidelines:
Hold the initial starting dose for 5 - 7 days (10 - 14 cycles) unless the numbers tell you otherwise. Kitties experiencing high flat curves or prone to ketones may want to increase the starting dose after 3 days (6 cycles).
Each subsequent dose is held for a minimum of 3 days (6 cycles) unless kitty earns a reduction (See: Reducing the dose...).
Adjustments to dose are based on nadirs with only some consideration given to preshot numbers.
Increasing the dose...
Hold the dose for 3 - 5 days (6 - 10 cycles) if nadirs are less than 200 before increasing the dose.
After 3 consecutive days (6 cycles)... if nadirs are greater than 200, but less than 300 increase the dose by 0.25 unit.
After 3 consecutive days (6 cycles)... if nadirs are greater than 300 increase the dose by 0.5 unit.
Reducing the dose...
If kitty drops below 40 (long term diabetic) or 50 (newly diagnosed diabetic) reduce the dose by 0.25 unit. If kitty has a history of not holding reductions well or if reductions are close together... sneak the dose down by shaving the dose rather than reducing by a full quarter unit. Alternatively, at each newly reduced dose... try to make sure kitty maintains numbers in the normal range for seven days before reducing the dose further.
If an attempted reduction fails, go right back up to the last good dose.
Try to go from 0.25u to 0.1u before stopping insulin completely.
Random Notes...
Because of the cumulative nature of Lantus and Levemir:
An early shot = a dose increase.
A late shot = a dose reduction.
A "cycle" refers to the period of time between shots. There are 2 cycles in one day when shooting twice a day.
Sometimes a dose will need to be "fine tuned" by adding some "fat" or "skinny-ing up" the dose.