
May 13, 2005
Other, Pills for Diabetes
Question from Lexington, Kentucky, USA:
My daughter was recently diagnosed with type 1 diabetes. Her endocrinologist said that she is still in the honeymoon phase of her disease and, therefore, still producing some insulin. Currently, she takes Lantus and NovoLog. I know that the drug metformin is used to treat type 2 diabetics. If I understand correctly, metformin makes the type 2 diabetic more sensitive to the insulin that they produce. If this is true, then why don’t doctors give type 1 diabetics metformin? Would this drug help make my daughter more sensitive to even the small amount of insulin that her body currently makes and enable her to use it more effectively without taking insulin? Even if she were not in the honeymoon phase, would this drug enable her to take less insulin?
Answer:
You actually are not entirely correct about the effects of metformin. At one time, this medication was thought to exert its effects by enhancing insulin sensitivity – and while there may be some mild component of that, the main mechanism of action of metformin is to decrease the ability of the liver to manufacture glucose (“decrease liver glucose output”). Thus, while on occasion, the use of metformin may be justified in the heavy type 1 diabetic who actually does also have some type 2 diabetes characteristics, the use of metformin in the “common” type 1 might actually be contra-indicated: if there were a serious low and you needed the body to compensate by making more glucose, you wouldn’t want an additional medicine on board that could interfere with that.
As an editorial, I commonly am very puzzled when a parent of a patient with type 1 diabetes, a state of clearly defined insulin deficiency, wants to “give the child less insulin.” Certainly, one wants to limit low glucoses, but insulin is saving the child’s life. You wouldn’t give “less oxygen” to a serious asthmatic; you wouldn’t give “less dialysis” to a child with kidney failure; you wouldn’t give “less heart-strengthening medication” to the person with congestive heart failure….
In addition, I often try this scenario: if you had a furnace that you knew was not working well, although still working some, you might want to get another furnace. But, if you couldn’t or couldn’t afford one, then in the meantime, you’d put up weatherstripping around the windows and doors and you might light a fire in the fireplace or place small space heaters in some of the rooms, all to allow your furnace to not work so hard. In diabetes management, dietary attention is the weatherstripping and extra insulin is the space heater. By giving extra insulin and meal planning in this manner, you are preserving/prolonging some pancreatic insulin production. This is why your child is having a diabetes honeymoon.
Perhaps my examples are not perfect but the REAL question to me seems to be that, if the REAL issue is recurrent hypoglycemia, then there needs to be as good a match of insulin-to food-to activity as you can get. The Diabetes Team at your University in your hometown is first rate. Talk with them about your concerns.
DS