Insulin pen misfiring?

How can you tell if the pen misfires? Last night I checked how much glargine was in my daughter's pen (54 units) and then we gave her the night time dosage. There should have been 45 units left in the pen and there was 41 units. I watched my daughter like a hawk to make sure that she didn't add more units and she did not. Because I checked I knew that there was a chance she had taken more that she should have and was able to compensate.

Has anyone else had a problem with a pen misfiring and administering more units of insulin/glargine administered than was actually dialled?

Thanks, Lynn

Hi LaughingHyena,

Thank you for the advice and the link. I will test that tonight. I want to change from the disposable pens to one you keep every six months for my daughter's night time dose. I will speak to the DNS.

Dear leggott

Thank you for the advice. Yes, as we are unable to trust the pen I've set it aside and am going to show it to our DNS. Hopefully it is just a blip/one off and the rest of the disposable lantus pens are not affected. It's the same pen we used when my daughter overdosed a couple of weeks ago and it worries me that the pen is faulty.

Thanks, Lynn