Answer to Question 1
Insulin is most often administered by subcutaneous injection, either self-administered or provided by caregivers (note that insulin is a protein, and would be destroyed by digestive processes if taken orally). Disposable syringes, which are filled from vials that contain multiple doses of insulin, are the most common devices used for injecting insulin. Another option is to use insulin pens, injection devices that resemble permanent marking pens. Disposable insulin pens are prefilled with insulin and used one time only, whereas reusable pens can be fitted with prefilled insulin cartridges and replaceable needles. To eliminate the need for multiple punctures, injection ports for insulin are sometimes inserted through the skin and left in place for several days. Some individuals use insulin pumps, computerized devices that infuse insulin through thin, flexible tubing that remains in the skin; the pump can be attached to a belt or kept in a pocket. Some of the newer insulin pumps include built-in continuous glucose monitoring systems.
A rapid-acting inhalation powder (called Afrezza) is available for use before meals. Because it cannot be used by individuals with lung disease, patients may require serial lung function testing prior to and after starting therapy with this form of insulin.
Answer to Question 2
D