Symlin and what I know about using itI've already written a few times about Symlin on this blog. Recently I got a long comment/question about how to use Symlin effectively. So I thought I'd share more of what I've figured out about Symlin and how I use it.
Warning to reader: this is how I use Symlin and generally it works for me. But the same approach may not work for you. Please use extreme care when using Symlin, the lows can be extremely bad, and they're difficult to treat.
I use an insulin pump and that's important because I don't know how I could use Symlin if I was injecting insulin. More on that in a moment. You can find some great information about Symlin on Children with Diabetes, and there's also a discussion group for Symlin users on TuDiabetes. Finally the makers of Symlin, the company Amylin, has a Symlin website.
Symlin FactsSymlin, or pramlintide, helps to reduce the blood sugar increase that you get after eating meals (postprandial high or postprandial excursion). It's an artificial version of the hormone amylin. Like insulin, amylin is produced by your pancreas in its beta cells. It works in three ways to reduce the amount of insulin you need to take after a meal.
- It makes you feel full more quickly (increased satiety)
- It slows down how food empties from your stomach, and
- It reduces glucagon production, which slows down glucose conversion by your liver
It's recommended that you don't take Symlin unless your meal contains at least 30 grams of carbohydrates. Symlin seems to last for about 2 hours after you inject it.
Symlin dosages are in micrograms (mcg). I use an insulin syringe to inject Symlin, so I think of dosing in terms of units like insulin. It's currently only available in 5ml vials, half the size of insulin vials. The FDA approved a Symlin pen recently and these should be available in December 2007.
How I use Symlin
I now take Symlin before most of my meals.
Initially I started with a 3-unit dose, and I've gradually increased that. I had terrible nausea for about the first 4 weeks that I used Symlin. This was so bad that I didn't want to take it sometimes and couldn't always finish my meals. While that was happening I couldn't take even a reduced dose of insulin until after my meal was over since I didn't know how much insulin I'd need.
Gary Scheiner of Integrated Diabetes Services suggested working on the breakfast dose. And once that was right, trying to get the same dose to work on other meals. That was really helpful because treating a Symlin low at bedtime is too scary to think about. So I used this advice to gradually increase the amount I injected until I got to a dose that worked for me.
Now I generally take 16 units of Symlin 10-15 minutes before I eat. I'll usually inject insulin using an extended (square wave) bolus about an hour after eating to take 20% less insulin over a 90 minute period.
This is why I can't imagine injecting insulin and using Symlin. Because timing a single injection right would be too difficult for me. Maybe it's possible to take Symlin, eat a meal and 30 minutes to an hour later take a single injection with a reduced dosage.
If my carb counting is reasonable, I'll see no blood sugar rise after eating. But most days what I end up seeing is a blood glucose rise of about 50mg/dL about 2 hours after I've eaten. So my blood sugars might go from 110 to 160, and then come back down fairly quickly.
I never take Symlin if I have more than about a unit of insulin on board from a previous bolus. If I'm about to eat and my blood sugar is high, then I'll partially correct for that with a regular bolus and then use my extended bolus after eating.
For me, Symlin has also caused my blood sugar to drop even if I don't inject at all. From talking with Gary Scheiner and Amylin, this is possibly due to the slowdown of glucose production from my liver. On my Dexcom I can watch this happening and I've even verified it by taking Symlin without eating and while I was doing basal testing so there was no additional bolus insulin on board.
Overall I really like the impact Symlin has on my blood sugar control. In April 2007 my A1C was 8.4, by July it had dropped to 7.0. I attribute this to a combination of using Symlin and my Dexcom CGM. In October 2007 my A1C has drifted up to 8.0 (blast!), but I'm retaking it to see if this is simply a lab error.
With the recent interest in glycemic variability, I think Symlin is an important tool for smoothing out after meal highs. My hope is that the Symlin pen is the first step on providing different ways to take Symlin and I expect to see more Symlin users in the future.
Update: I wrote a review of the Symlin Pen in January. I like the overall design and it's much easier than carrying round a vial of Symlin and a syringe.
Note:I have purchased shares on Amylin in the past and I may do so in the future. I work not to let my investments influence what I say on this blog.