Faulty insulin pen ???

[EllieM]

A couple of days ago my blood sugar climbed relentlessly and my short acting insulin didn't appear to be having any effect. So I tried dialing up 20 units to see whether it would fill the cap of my needle to the line, and discovered that it was only delivering a couple of units.

I tried changing the needle - no difference.

I then took out the cartridge and put it back in again, and it seems to be working normally again.

Anyone got any suggestions as to what is going on here?

edited to add it's a humalog pen

 

[Antje77]

Yikes, that's very odd, and very unlucky!
No idea on what might be going on with your pen, but this would make me distrust any dose from that pen for a while, which in turn would cause quite a lot of anxiety and stress.

Hopefully someone else will have a more useful reply.

 

[Antje77]

On second thought:
Can it be the cartridge wasn't in exactly right?

I've once noticed I didn't screw my pen (Novopen) all the way to the click after changing the cartridge. It still felt like the pen was normal upon injecting. (I found out pretty soon, and with a very smal correction dose, so no way to tell if it affected the actual dose.) If this happens it makes sense to expect the cartridge to be just a tiny little bit higher than usual.
In which case the needle may not stick completely through the rubbery part of the cartridge, or it may push the cartridge a tiny bit up with the added pressure of injecting.

 

[EllieM]

Well I've just discovered that the old cartridge was cracked and broken at its end, so I think I have an explanation that gives me more confidence in the pen.

Strange that it seemed to work after I took out and replaced the cartridge though.

 

[Ushthetaff]

I’ve had a few cracked cartridges but I found out really quickly due to the smell but one took a few days as the crack was very smallbut as time went on my detective “hooter “ started alarming

 

[Jaylee]

Well I've just discovered that the old cartridge was cracked and broken at its end, so I think I have an explanation that gives me more confidence in the pen.

Strange that it seemed to work after I took out and replaced the cartridge though.
View attachment 64584

I’m guessing more insulin was pushed out the crack than the needle.

Then when the bung got past where the cartridge split, normal delivery was resumed?