V4 Pen - Final/Partial Dose from Cartridge Question

[coondogesq]

I apologize if this has been answered before of if the answer is intuitive. I have never used the pens before and am getting ready to load my first pen.

I understand how to use the pen for a standard dose (I.e., click up the number units needed). My question is, when you near the end of the cartridge, how can you determine if you only a "partial" dose remains and if a partial dose is administered, the amount of such partial dose? I want to be able to complete the dose with the next vial/cartridge but need to understand better how to determine that amount?

With the syringe its easy to determine how much is in such partial dose and how much more is needed.

Please advise with any insight regarding the pen (I have a V4).

Thanks.

[Nuncles]

If you set the pen to 50 units and there is approximately 30 units left in the cartridge, the pen will stop at 20 letting you know that you only injected 30 units. And thus will need another 20 units to complete your dose.

There will be a small amount left in the cartridge that wasn't able to be pushed by the plunger. Either dispose of the small amount left along with the cartridge or use a disposable insulin syringe to remove the little bit left in the cartridge.

[coondogesq]

@nuncles Makes perfect sense. Thanks.

[keithvarin]

Personally, I always pull my last dose with a syringe.

[Nuncles]

@keithvarin said:

Personally, I always pull my last dose with a syringe.

I will probably start doing this as well. Below is my observation on the Xulin pen. Not the V4. I tested the V4, and the plunger does indeed stop right when the needle stops injecting.

I was down to my last shot in a Xulin pen so afterwards I decided to test my own advice with some water in the empty cartridge. Well low and behold. The Xulin plunger continued to push down just a bit (almost 10 units) without extracting anything from the needle. So going forward, I will either replace the cartridge when it gets below the last line or just pull whatever's left into a syringe to be better safe than sorry. I may have just short changed my dose on that last shot. Again, this is with a Xulin pen. One interesting thing to note is that the Xulin leaves a good amount less in the vial once the plunger stops. The Xulin had around 4 units left inside where the V4 had around 10.

[Coyote_Hippie]

New researcher here and moving to pens, I've been using 31g 5/16" syringes. What needle tips are used for Xulin pens? 31g or 32g and best length for pinning. Thanks for sharing your insights and help

[Nuncles]

It's really a personal preference. I've been using 32x4mm and 32x8mm. I don't notice much difference. I tend to grab the longer needle for higher unit shots. Next go around I'll probably order 31 or 32 gauge 6mm and call it good.