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Old insulin pen dispensing wrong dose???

EllieM

Master
Retired Moderator
Messages
10,497
Location
New Zealand
Type of diabetes
Type 1
Treatment type
Pump
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hypos and forum bugs
I've recently been having issues with high morning blood sugars (I'm on a lantus/humalog basal/bolus regime) and after
1) changing over my insulin cartridge (OK, insulin was a few months from expiry)
2) increasing lantus by about 20% without much effect

my GP suggested I should try changing pens, Now I've done this and things have improved so am wondering

Do old pens become faulty???? (I've had one completely break before but don't know whether they can start dispensing the wrong dose...)

Having said that, it's only been a couple of days, so the jury is still out.
 
You can check by clicking 20units from old pen into your pen needle outer cover. If the part for the needle isn't filled to the top, your old pen is faulty. This happened to me, months ago, and it was only half filled.
 
Hi @EllieM ,

I agree with @dancer . 20 units should fill up to where I put a red line on the needle cap picture below?
As a quick pen accuracy test. (Don't forget to do an airshot first, to prime the needle.)

 
@Jaylee your photographic and artist work is something to behold!

I can never remember how many units fill the tip of the outer cap, and tbh I've never looked but do they print '20u' or something anywhere on the cap as a aide-moi........?
 
@EllieM don't know which pens you use but I did have a novopen 3 or 4 that started to 'slip' (ironically!) when pushing the plunger - annoyingly only did it sometimes - but I definitely could feel/hear when it did but had no idea how much insulin I did or didn't get.
 
therower said:
@Jaylee .
If that's not a 1950's picture of a UFO spotted over Area 51 then I don't know what is.
Click to expand...

Yeah, crop circles in Wiltshire.. It is a bit grainy. Just felt it was the best way to describe where the 20U should stop.

slip said:
@Jaylee your photographic and artist work is something to behold!

I can never remember how many units fill the tip of the outer cap, and tbh I've never looked but do they print '20u' or something anywhere on the cap as a aide-moi........?
Click to expand...

Thanks! Lol.

Basically? They don't print the measurement on the side of the needle cap. It just so happens that the end takes 20 units before it starts to flute out.. I was given this tip by my GP many years back when I was having pen trouble after a ballet dancer sat on it. (Don't ask.)
 
If memory serves me right, I believe the 20 units in the needle cap information is listed in with novopen instruction pamphlet.
I should imagine that it is a requisite of all needle suppliers to conform to the design/ fluting with their caps.
 
therower said:
If memory serves me right, I believe the 20 units in the needle cap information is listed in with novopen instruction pamphlet.
I should imagine that it is a requisite of all needle suppliers to conform to the design/ fluting with their caps.
Click to expand...

Twin-bro, doesn’t matter if they all conform to the 20u fluting I still will forget its 20u

And who has their pen instruction manual? Ok I do, but some where safe, which means it could be anywhere in the house
 
slip said:
Twin-bro, doesn’t matter if they all conform to the 20u fluting I still will forget its 20 u

And who has their pen instruction manual? Ok I do, but some where safe, which means it could be anywhere in the house
Click to expand...
This is why we have big bro's to keep us safe.
 
Thanks to everyone who posted. Seems to be OK ....hmm...
 
EllieM said:
Thanks to everyone who posted. Seems to be OK ....hmm...
Click to expand...
I said this happened to me, months ago. I only use a pen if my pump isn't working properly or I have high ketones and need a correction dose. It had been a long time since I'd had to use my pen, so decided to check it was ok. After an air shot, I pressed 20 units into the outer cap and it only came up halfway. It was my only pen, so I decided to try again. This time it did fill the outer cap, so seemed to be working. Obviously I couldn't trust the pen in an emergency, so I asked GP for a new one.
 
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