Comparison of the effectiveness of various routes of insulin injection: insulin levels and glucose response in normal subjects

Very interesting... puts some rigorous research data behind my own experiences with IM vs subQ administration.

Acid's comment in a different thread that he's actually done an IV injection in his rockstar-crazed youth :-) has got me pondering a very, very conservative experiment with this technique next time I have a stubborn, nasty high. Which may happen this weekend, given our plans.

By very conservative I mean calculating the correction dose, then administering like 25% of it IV. Then wait and see what happens. From the abstract excerpted below, sounds like I won't have to wait long to see what happens!
From PubMed:

The difference in absorption of insulin and its glucose lowering-effect after the administration of crystalline insulin by the intravenous, intramuscular, and subcutaneous routes was compared in 14 lean normal subjects. Insulin in a dose of 0.1 U/kg body weight was given by the three different routes. Blood was drawn from the opposite arm at regular intervals for the determination of insulin, glucose, glucagon, cortisol, and potassium. Intravenous insulin produced the highest pharmacological level of insulin in 2 minutes (2099 +/- 414 muU/ml) with marked hypoglycemia at 30 minutes (a 68% drop). Intravenous insulin injection produced an increase in plasma glucagon and cortisol reaching a 2-fold increase above the fasting level 30 minutes after the glucose nadir. An equivalent amount of intramuscular insulin produced a maximal increase in plasma insulin at 50 minutes (45 +/- 4 muU/ml) and caused a 35% drop in plasma glucose at 60 minutes, which effects were greater than those caused by subcutaneous injection (highest IRI = 36 +/- 3.5 muU/ml and 23% glucose drop at 180 minutes). No significant increase in glucagon or cortisol was noted with equivalent amounts of subcutaneous or intramuscular insulin injection. Our studies suggest that, in normal lean subjects, insulin injection by the intramuscular route provides a faster absorption of insulin with a concomitant greater drop in plasma glucose than does injection by the subcutaneous route.

IV shots are very dangerous. I still do them if my BG is very high. I don't let it get that high very often.

Agreed. Dangerous. Bad idea.

A pump delivers subcutaneous insulin. Why would it be anything similar to the IV route? With a pump, you're supposed to change basal rates 1-2 hours before you want them to take effect (i.e., if you're exercising and want to use a temporary rate, you're supposed to start the temporary rate an hour or more before the exercise).

If this study had been run on type 1 diabetics of at least 20 years duration, I would find it more interesting. But, only slightly interesting. A non-representative study of 14 normals may qualify as a pilot (preliminary) study. Period. It can have no clinical implications and I know that some of you are in science fields and know this also. It can suggest the need for a larger, scientifically rigorous, study.

I consider it playing with dynamite to test IV insulin without medical help & equipment standing by. Like, in the same room. But, that is just my opinion.
Oh, one more thing on the normals. They have skin and bodies unmarred by years of external insulin usage. Think there might be different metabolisms at play?

Hey, Dave - You still kicking? You crazy Guinea pig, you. Just checking your still alive.

I wonder how this interacts with the liver clearance dynamics you raised in the Afrezza thread. Presumably IV insulin is at least as fast, or faster, than Afrezza, which presumably also means it has similar clearance dynamics and is similarly hypo-resistant. IM should be somewhere in between. Sound right?

No pressure, but after your incredibly insightful comments in the Afrezza thread, you're sort of my new TuD guru. :)

Oh, don't oversell me... there are some others here I won't name that really despise me :-)

I would expect IV administration to be very similar, just a bit faster.

Yo -- alive and kicking! I had an opportunity to try an experiment, but in light of all the Afrezza news, I decided to abandon the idea for now. I'm going to request a try at Afrezza first.

A pump isn't faster than MDI, though... It's the same speed since an injection and infusion set are both subcutaneous. There's no speed advantage to using a pump versus an injection with corrections, and in fact lots of people fall back on an injection when they are high just in case there's an issue with the infusion set.

If I give 2 units with a pen, it's injected within a few seconds and sits there until absorbed. If I give 2 units with a pump, it takes maybe a minute to complete the injection, and sits there until its absorbed. The other difference is that with the pump, all my insulin for those 2-3 days is going to that one site, but whether that matters I'm not sure. But I don't see how the dose is meaningfully different between MDI and a pump. Basal is obviously different, but that's not relevant to this conversation.

"Dangerous" is a variable term.

It's very dangerous for my wife to mess with gasoline power tools, like chainsaws. Not because she's an idiot or anything, she simply has no experience or knowledge (well, she has some now). As a result, she almost burned our house down -- and herself, trying to start a detritus burn on our side yard with gasoline from a near-empty container use to refill the chainsaw. Thought it acted the same way as kerosene, which she's seen ME use to start a detritus burn.

Danger in me using gasoline for just about any purpose? Close to zero.

There are countless other examples that make the same point.

If I were some jaboney who knew nothing (or worse, knew "wrong stuff") about how all this generally functions, it would be insane.

However -- and I'm not bragging, just keepin' it real, brutha -- I know a ton about this subject. My endo has given me tremendous latitude, including happiness with my IM protocol, because she believes I'm knowledgeable.

Now, all that said, an IV injection is not something I have any experience with. But I know enough about how the systems work generally, and plenty of experience with how my own body varies in that regard, that I'm confident I could do this experiment without significant risk.

Again, keep in mind what the proposed experiment was: With a big high, administer ONE QUARTER of the calculated correction bolus IV. Do not administer any other insulin in any other manner. Watch the CGM for the next hour or two. See what happens.

My guess is I'd see about 1/4-1/2 of the high corrected.

I had decided to put this off because of Afrezza... Lord knows I'm not going to start a regular practice of IV injections as an arrow in my quiver, when Afrezza seems to be accompishing the same thing but much more easily, and yes, much more safely.

Yes, some do say small doses (under 7 units, I believe) absorb better. This would be the same whether you were injecting the dose subcutaneously with a needle or with an infusion set, though.

And folks wonder why stuff like insulin requires an RX. There is not much doubt that an IV or IM shot of insulin will lower the bg faster than a subQ shot. There are risks associated with this method of delivery of course, and this is why they monitor patients in a hospital when IV is administered. The day Insulin pumps come up with IV site set products I will eat my hat. I can't help but laugh at idea of "normal subjects" in the title of the thread. I enjoy "normal" without dangerous experimenting on myself. Good luck with your experiment, Dave. Please take care when you get around to doing this!

I trust ya, just gotta be careful to always put the disclaimer on the internet. There's a lot of people, desperate to find solutions to difficult problems. You know.