Type 1 Fiasp Insulin acting like water?

Sandra_W said:

Hi everyone, As a T1 diabetic of 50 yrs, I've been on most types of insulin over the years. Recently I've been put on Tresiba basal and in last few months put on Fiasp bolus Is it just me, or has anyone else felt that every now and again, your new insulin pen is only injecting water? This has happened to me twice now. Start a new pen, BS shoots up into high teens for no reason. First time it happened I was panicking for a week and a half why my sugars were so high, then started a new pen, and suddening they're back down in low singles.... Started new pen last week again and same thing has happened, up in late teens, gave up after 2 days and started another new pen from same batch, back down to low singles. Has anyone else had this occur?? Just can't figure out whether they've got some faulty insulin, or whether something strange is happening to my aged body

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Hi Sandra, I am a T1 of 49 years and use Tresiba/ Fiasp (not in a pre filled pen though). I experience very similar things to you. Suddenly my BS will shoot up 17+ for no reason. Then I end up giving correction doses to get the BS down. This can mean injecting considerable large doses of Fiasp. for example I might eat 50gms and inject 10 units of Fiasp which works well with BS under 10 after the meal.. Then another time the same meal and ratio will see BS of 17 and rising. It can take over 25 units of Fiasp to bring it back down into the ideal range. This means 35 units for just 50g on a 2-1 ratio, As you say its as if its water......

I have been using two pens for my Fiasp injections (one at home and one for away from home) This does mean that the insulin is exposed to room temperatures for longer as i switch between the two pens. So I suspect that this may have a bearing on my syptoms. So I have started to just use one pen so the Fiasp is used up quicker before possibly going off. It too soon yet to tell id this fixes my problem,

However it could be that having T1 for such a long time the absorption rate in injection sites is very poor, or I have selective insulin resistance. However you are not alone with Fiasp playing up.

One effect that definitely happens for me is that with high bg my insulin sensitivity is severely changed. For example, to get my bg to go from 10 to 8 I need about a 12 unit bolus. To get my bg to go from 28 to 26 I need probably double that, so a 24u bolus.

I mentioned this excitedly to my doctor, thinking I'd discovered something new. Yeah, he said, it's a well known effect. It would be nice if they told the diabetics, you know, the people who need to know to get their insulin dose correct.

It doesn't explain why you're getting the initial peaks, but you should need more insulin at high bg.

Why the difference is so distinct between pens from the same batch, though.. You've ruled out all the obvious suspects I suppose. Heat, cold, sunlight, shelf life etc. Stored in the same place in the fridge. Sorry, drawing a blank here.

I've been using FIASP for around a year now, with Tresiba for the last 6 months or so. I also found that sometimes its like injecting water. However I have noticed that this is generally when its been in my pocket for a while, also noticed it is more susceptible to heat and goes off very quick.

However, I've never had it happen straight out of the fridge. I exercise mon-Friday and usually have weekends off, and I know that drastically increases my insulin requirements, especially basal.

Same here, novorapid 1 to 10. Fisp 1 to 10. Then overnight 3 to 10! Consultant just skipped round issue, offered no help at all, same diabetes nurse, diabetes nurse at drs admitted she never heard of fiasp not up on type 1.... switched back to novorapid still 3 to 10 :'( gutted I used to jab and forget, it's taking up every minute of my day watching diabox. Hoping it wears off and ratio comes down.