Why is Afrezza "weaker" unit per unit

I’m on a regiment of Tresiba + Afrezza and realized I hadn’t calculated my TDD since starting and went to do it. I remembered that it’s like 1U injectable ~= 1.5U Afrezza but I can’t figure out the why.

I found this old blog thing:

And it shows that the blood insulin levels of 8U Afrezza vs injectable but the “work” done is less. Could that have problems later IE could it act like hyperinsulimia?

Or am I just over thinking all of this?

I’ve been using Afrezza for six years now, almost exclusively for corrections. Like many others, I observed that Afrezza acted differently than injected insulin. It’s onset, peak and duration all occur sooner than the injected insulin. It’s not important to me why this is the case. It’s only important to me that that is its nature and it is repeatable.

When I account for an Affezza dose, I track it as 50% of its nominal dose. So, when I take a 4 unit Afrezza dose, I find its effect most closely tracks a 2 unit injectable dose. Its onset, peak and duration are all shorter but the cumulative effect approximates about 50% of liquid insulin for me.

A lot has been written about Afrezza on this site. I suggest that you search using Afrezza as the search term and you will find many discussions about this aspect of Afrezza as well as many others.

@Sam19 also uses Tresiba plus Afrezza.

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You just can’t compare Afrezza units to injected units. Totally different thing. They tell you that when you start with them, if you speak to a rep (which I did when I started on it). It’s also different because it’s out of your system so fast, which is great for some things, less good for others. So I use it in conjunction with Humalog (and Tresiba for basal), because I need to Humalog to cover longer/slower rises (high protein/fat meals), but the Afrezza is great for corrections and carby food.

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I understand the ratio that goes in to Afrezza dosing, I use it quite well. My concern is to why. I’m sure if you used 40U TDD in a pump with Humalog, switched to Novolog, and then your TDD went to 60U (no other changes) you’d have some concern.

I think it’s just in the manner of administration… you’re inhaling it so obviously you’re exhaling some of it too without absorbing it—- some of its landing inside your mouth etc etc. I don’t find the number of units of afrezza particularly meaningful

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Yeah I just don’t think you can compare it meaningfully is my point. So no, I’m honestly not concerned about the difference the way I might be with humalog vs novolog which should be roughly equivalent.

Might just be me then since actual mg of insulin matters in my head (doesn’t mean my worries are justified!). This helped somewhat.

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