Splitting Insulin Glargine Doses

I've been asked (again) about optimizing how to give the dose of Lantus (insulin glargine), so I decided I'll share my thoughts on-line. First, a disclaimer: (1) I previously worked for Aventis and later Sanofi-Aventis [and then Sanofi], the manufacturer of Lantus, in the area of pharmacovigilance (drug safety). (2) The advice given here is "off-label" (that is, it's not approved by the FDA).

Lantus is the brand name for insulin glargine, a very long-lasting insulin product that was approved by the FDA in 2000; it was first sold in the US in 2001 and is now available world-wide. It was originally marketed as "peakless", but the marketing folks soon changed the wording to "no pronounced peak." The whole idea was that Lantus lasts longer than a day, so if you inject it once daily, the previous day's dose is still lingering, and smoothing out the action of the insulin. (BTW, logically, if only one dose of the insulin were to be given, and no other insulin doses, every insulin, including Lantus, would have a beginning, a peak, and then a decay to no-activity sooner or later.)

However, many patients and their physicians noted that even with its long duration of action, Lantus does have peak activity at one time of day, and the effect drifts down towards the time the next dose is due. The company countered by saying that the dose could be given at different times of day: "Once a day, at the same time each day. Most people take Lantus at bedtime, but you can take it at other times if your healthcare professional says it's okay."

But the company adamantly refused to do studies that would show the effectiveness of twice-daily dosing; I suspect the rationale for refusing was that it would spoil their marketing message that it was a once-daily insulin.

Anyhow, it soon became evident that splitting the Lantus dose into two more-or-less equal doses, given more-or-less 12 hours apart, smoothed out the ups-and-downs. I myself was on a split-dose of Lantus back in the days before I started an insulin pump: "I draw up 15 units each evening into a standard insulin syringe, and inject, then immediately draw up another 15 units and leave in the basket on our breakfast table for the next morning. (If I forget the evening shot, which has happened, the empty spot in the basket is the tip-off - and I simply give 20 units instead of 15 that morning.)"

Well, that's how I split my Lantus dose. But if you're on a single-daily-dose of Lantus, you might wonder how to make the transition to two-shots-a-day. Here's my proposal for how to get started -- of course, review this plan with your physician or diabetes nurse educator before implementing it!

1) Start with the daily dose of Lantus that you are presently using. Let's say it's 30 units per day, given as a single shot once a day.

2) Divide that amount in half (15 units).

3) Plan to start the new doses when you'll have a few quiet days where you can check lots of BG levels (perhaps on a Saturday and Sunday if you work a Monday-Friday job). As an alternative to starting on a weekend, you might plan to start when you expect to be able to reach your physician or diabetes nurse educator just in case glitchy things happen.

4) On the starting day, plan to check a BG level before each meal and at bedtime, plus another at 3AM (yes, that's 5 BGs a day).

5) Whether you are presently giving your Lantus in the morning or evening, start the new program on the first morning by giving only 15 units instead of 30. Most folks give their morning insulin dose before breakfast; it really doesn't matter for Lantus whether it's before or after eating, so choose a time that will be easy for you to remember.

6) On the first evening of the new program, give 15 units more. Evening doses of Lantus might be given at suppertime (either before or after) or later at a time that's easy for you to remember, perhaps at 10PM if you watch a TV newscast at that time. Whatever works; it doesn't have to be precisely 12 hours after the morning shot of Lantus.

7) On subsequent days, give 15 units twice daily (which is what you did on the first day). Continue frequent BG testing for a few days to see if there's less bouncing of the BG levels.

8) As soon as you see a pattern of BG levels, call your physician or diabetes nurse educator and let them know how it's going.

This concept of starting and maintaining a twice-daily Lantus program should work equally well if you have type 1 diabetes on both Lantus and short-acting mealtime insulin, or if you have type 2 diabetes and are only Lantus.

Hope this helps!