I’m wondering how long a dose of Symlin can be considered effective. I take 60 units of Symlin before a meal and take insulin (cut to 50% of the “normal” dose) after the meal. This system works well.
Occasionally, especially during the holidays, I find myself in situations where I eat food, although not a full meal, closer together than the five to seven hours apart I normally keep my meals. My question is how long after a mealtime dose of Symlin should I cut the corresponding insulin dose? Dose its efficacy scale such that one hour after a meal insulin should be cut by X% and two hours after a meal it should by cut by Y% instead?
60 UNITS ??? never more than 20 units before a meal & since it does not affect your insulin, i dont do anything different w/ the insulin. you may want to recheck your instructions cuz they sound way off to me. im surprised you havent run into problems
Sorry, that should be 60mcg. I used the wrong description of the unit.
Regarding the insulin, for me (and for most others I’ve read about) adding Symlin to an insulin regiment lessens amount of insulin required with a mealtime bolus. For me, I find that taking 60mcg of Symlin as I start eating and using 50% of the calculated bolus as a square bolus over one hour starting 15 minutes after the meal proves effective.
I found the “Practical Symlin Guide for Type 1 Diabetes” (parts 1, 2, and 3) to be a useful starting point and adjusted from their.
Hello Aaron,
Since your post is from January I am sure you have figured out exactly how much insulin/symlin to take when. I have only been using symlin for 5 weeks. I am type 1 with pump and CGMS. I take 45 mcg now and about 60% of insulin before meal. Then at 2 hours later I take more insulin because for me the BG starts going up and the symlin is gone. The help people at Symlin told me it lasts longer but I find if I eat something after the two hour mark is need all my normal insulin. I do like the way the BG doesn’t go up for 2 hours. That is amazing I think. When it does go up I can handle it easier with a bolus. Others tell me the square wave works but I haven’t had success with it. I go low during the two hour period of digestion.
MaureenH
Thanks for posting this Practical Guide, Aaron (and thanks to the person who wrote it). I rarely read blogs but I have a feeling as I start on Symlin this one will be very useful!
Aaron,
Your blog part 1 is the best I have read. Is it alright if I post this to another list, the one for CGMS pump users. Maybe I will also post it to the insulin pumpers list. I will add your name and information as the author. thank you for all your good information. I don’t understand why more type 1’s aren’t using symlin. My doctor didn’t want to prescribe it for me. He said I was in “good control” and not overweight. I think it is great to be able to eat and not have a BG spike. (I did lose 5 pounds which I like too.) Maureen H
I am fairly new to symlin and still learning about it…I use 1/2 the insulin before a meal and inject 30 mcg of symlin right before the meal. for two hours, everything goes smoothly and then BOOM…I get a spike of 190-223 after the 2 hours!! so frustrating as it takes me forever to get it back down again. any suggestions? I’ve got a call in to my endo, perhaps upping the dosage of symlin as I know I’m on a low dose? or perhaps taking my meal time bolus AFTER my meal??
I hate going to bed every night being stressed out about my HIGHS.
Debbie,
I think this is the way symlin works. It delays the digestion but two hours later you will have the rise. I find like you that the BG goes up two hours after a meal. I just bolus then, and do about 1/2 of the bolus I didn’t give before. If you have been on the 30 mcg for a week you might want to try the 45, but if your BG is down for the two hours that is how it works. I am now at 45 and thinking about trying the 60. I still like it like this because it is pretty easy to bring down the BG 2 hours later. As soon as I see the BG start to go up, and I look at the clock, I do the bolus.
Maureen,
The blog posts weren’t written by me. They are just links I too found very useful when I started to use Symlin. I would certainly advocate greater dissemination of the information, but it ought not be attributed to me.
Thanks.
I did, in fact, figure out a rule of thumb for myself. I treat the Symlin as having full efficacy for about two hours. I then basically treat the Symlin like it loses about half of its efficacy every 40 minutes of the next two hours (basically like a 40 minute half-life). So, at two hours after an injection, I would still take 50% of the insulin. At three hours, I would take 80% of the insulin. At four hours after an injection, I would take 100% of the normal insulin dose.
I found that I maintained much better post-meal readings when using a square bolus. If I took a normal bolus, I would consistently end up going low a couple of hours after the mean. Even with the square bolus, I found that taking the insulin after the meal (as unconventional as that might seem) prevented lows that I would get when taking the insulin before the meal.
Your answer is interesting. I have been taking half the insulin up front, no square wave or I go low, and then the other half plus perhaps a little more at exactly 2 hours. You also mention the two hour mark. Maybe doing the insulin at the end of the meal would help but I am so used to doing it before I am afraid I might forget at the end. I need an alarm at the two hour mark. Maybe I can set a BG reminder alarm. Now I watch the clock because I have the CGMS and I see the rise at two hours. How do you know how much symlin to use? I am at 45mcg. I think that is my level. I tried the 60 but went low too often.
Debbie,
I did discover there is a real problem with eating late. I was in New York for Easter and we ate about 9:30 p.m… With the symlin that meant my rise was about 11:30. I was in bed by then and very discouraged to see a BG of close to 300. I think I just won’t take the symlin if I eat late. Normally thought I find it easy to bring down the high when there is no food around. If I eat at 6 pm I can bring down the 8 pm BG with a quick bolus.
MH
I did notice that when I posted the information. Tonight I even passed out copies of part I to pump group members in Baltimore, MD. I gave credit to Jason. Someone asked about the part 2 and 3 and I sent them to Tu Diabetes, but it is not easy to find. If you hadn’t posted it we wouldn’t know that, so thanks anyway for the post. I still find there is not much about symlin on the net and I think it is very good. I got a message today the JDRF is tying to combine symlin and insulin, but that will be a while coming.
I have the same problem. I found that injecting symlin first and then my Apidra(mealtime insulin) 60 minutes later seems to cover that post 2hour spike. Since symlin slows digestion it seems to effect the BG levels at a slower rate, hence the smooth BG’s for 2 hours and then a spike.
