I was wondering how do you guys deal with dual square boluses on your pump while on Symlin? Do you cut by 50% only the portion of the bolus that you are giving yourself right after the meal or the entire bolus?
Honestly, I don’t think I’ve ever done a combo/dual bolus with symlin.
Great question though, for those special foods!
I always do an extended / square wave for a 90 minute period. I found I need the same amount of insulin, just spread out.
If I need a correction, and it’s not a scary amount of insulin (relative to me) I’ll deliver that all right away.
And don’t be fooled into thinking I have it all figured out. Just doing my best to avoid major disasters! 
Manny: for me it’s a bit different with the timing of the meal. For a high carb breakfast when I’m most insulin resisant (oatmeal w/fruit) I bolus my normal amount, 50% 20 mins before eating, and the balance over 90 minutes. This keeps me pretty smooth. I take the Symlin about 15 mins before the meal also. No longer or i start to feel a little funky. For my lunch meal, I take the Symlin right before the meal and give about a 40% reduction in insulin over 90 mins (none upfront). I’m assuming some of the morning Symlin is still working in my system. Otherwise I will have a wicked low about 1 hour following lunch. The same for dinner. I started with recommendtions from the following site and worked out the details for me afterward. If you test evey hour post prandial for a couple of days you get it figured out. Then…someting will change. Ain’t it great!
http://www.bernardfarrell.com/blog/2007/11/symlin-and-what-i-know-about-using-it.htm
The only time I give myself a dual wave bolus with Symlin is if my BG is above the normal range, then I give just what is needed to correct it. The bolus for the meal is always square. I inject the Symlin no more than 5 minutes before my meal, because at about 15-20 minutes, it completely turns off my appetite. I often wait until after I eat to dose my insulin, unless my BG is high. This way I know more precisely how many carbs I ate and can in turn dose more precisely with my pump. Symlin gives you that cushion, and then some. Like others, I’ve had problems with post-prandial lows which are made more difficult by the fact that the Symlin inhibits your ability to get glucose digested to correct the hypoglycemia. You know the spiral from there, I’m sure. Dosing immediately post-meal tends to prevent this from happening, at least in my case.
I also need about 60-70% less insulin to cover the meal than I would without the 120mcg Symlin injection. One oddity I have noticed with Symlin is that when I drink a protein shake or eat a very high protein meal, I will sometimes have hyperglycemia 3-4 hours later that is difficult to control. I attribute this in part to my own shortcomings in understanding how to bolus a square wave for that long while maintaining ideal numbers in the interim.
I have changed my dose that I don’t remember the original dose to tell you what percentage of the original I use now with the Symlin but I do believe it is less. I always do 50% normal and 50% square waver for 3 hours and this gives me just a small smooth rise of about 30-40 mg/d. after meals. Unless of course I miscalculate carbs or something else effects it. I also find it is difficult to correct a low when I exercise after a meal.
endo told me to just halve my dose but use the same dual wave as pre symlin—start at 50% of my normal insulin dose and correct after for anymiss until the symlin is fully titrated to whatever I can handle
Dinner last night --perfection after dinner–didn’t break 150 and down to 120 2hrs after–breakfast this morning–still got the peak afterwards–so will correct after I get to work so no surprise low while i am driving–
I don’t cut it in half. I merely take 30% up front and the rest over 90 minutes. It is pretty much a trial and error till you find what works for you.