** Insulin pens more expensive material in the short term from insulin injections.
** Often be lost unit or two units of insulin when you try to calibrate the pen to adjust the dose.
* Often is the survival of some insulin in the cartridge or pen when you get rid of them.
* Not all types of insulin available in the form of pens.
* Patients who use pens can not mix types of insulin in the same pen.
* In the case of the need for two types of insulin should be injected each type alone when using pens.
