I've been following closely news of the inhalable insulin, Afrezza, since I became aware of it a few years ago. Its purported faster action was the main feature that interested me. I understood that it peaked in 12-15 minutes but it appears that my understanding was not complete.
After doing a google search on Afrezza yesterday, I discovered that the official prescribing information is now available. On pages 15-16 under the clinical pharmacology section I found this narrative:
Absorption: The pharmacokinetic profiles for orally inhaled AFREZZA 8 units relative to subcutaneously administered insulin lispro 8 units from a study in 12 patients with type 1 diabetes are shown in Figure 3(B). The maximum serum insulin concentration was reached by 12-15 minutes after inhalation of AFREZZA 8 units and serum insulin concentrations declined to baseline by approximately 180 minutes. However, the faster absorption of insulin from Afrezza [see Figure 3(B)] did not result in a faster onset of activity compared to insulin lispro [see Figure 3(A)].
While the serum insulin concentration peaks in 12-15 minutes, this quicker absorption did not lead to faster action.
Now I'm wondering how this insulin will really help me. The main attraction to me was to pull down high BGs quickly. If I interpret the referenced published information correctly then the onset of action for Afrezza is comparable to insulin lispro (Humalog).
The Figure 3 graph does show that Afrezza leaves the system well ahead of insulin lispro. That's an important benefit.
I guess I'll just have to wait and try it myself to see if it will help me but for now I am disappointed. Again, the devil is in the details.