We are finding that effectiveness of glargine diminishes within the month after first using the vial. It appears that three weeks is the maximum time in which to be confident in its’ action yet the product literature suggests that a vial should be effective for a month after first use. Has your team any comment on why this may be the case? At the price of glargine, one would hope that the manufacturer would take note.

We have not heard or seen of glargine insulin effect waning at the end of a month as long as there are not temperature extremes of exposure. However, with many children in our practice using glargine, our most common use is a twice-a-day dosing schedule since it is clearly not a 24 hour insulin basal effect for most type 1 patients. And, there are some who need larger amounts in the morning than at bedtime while most need about 80% at bedtime and 20% in the morning to get full basal coverage. This is not a waning effect from open bottles and shows up all the time not just at the end of a month’s use with rising later afternoon and evening blood glucose levels.

SB