Glucophage®
| Author: Judy Kohn, RN, BSN, CDE |
| Last Updated: Wednesday, February 22, 2006 |
Q: "Can you explain to me how Glucophage XR® works? I have lost 14 pounds since being diagnosed and I am successfully keeping my blood sugar under control by counting carbs. I am supposed to take two-500mg pills in the morning & two at night. Actually the orders say 2 twice a day. I have found that I don't need the medication in the morning as I don't eat much breakfast and I go to an exercise class 5 days a week. So I take 1 or 2 pills at lunch depending on how many carbs I am going to eat. If I know that I am going to have a higher carb meal at dinner then I will save 3 pills to take then. Is this the right thing to do?"
A: While I will explain how Glucophage works, I want to emphasize that you need to consult your diabetes team, as I'm concerned that you have not been given adequate guidance regarding how to take this medication. Generally you should not be varying your dosage of Glucophage the way you are currently doing. Please read the review of glucose, insulin, and the defects in diabetes.
How the body uses glucose:
- The cells in your body need glucose to function. You get glucose both from the food you eat and also from glucose that is stored in your liver.
- Every time you eat, the level of glucose in your blood rises; this stimulates the pancreas to release more insulin. Four to five hours after a meal, your blood glucose level returns to baseline. When you haven't eaten for a while and during the night when you are sleeping, your liver releases stored glucose to supply you with energy.
- Insulin is released in response to glucose in the blood.
How insulin works-it has 3 main roles:
- Regulates the liver from releasing too much glucose (I like to say that insulin leans up against the door of the liver and only lets a little glucose out at a time). When there is enough glucose in the blood, insulin tells the liver to shut down its production of glucose.
- Acts as a "doorman, or key" to open the doors of the cells (called receptors) and to allow glucose to enter the cells so the glucose can then be turned into energy.
- Acts as a "traffic cop," directing some of the glucose to be stored back into the liver and the muscles, and if you eat more than you need, the excess energy is stored as fat.
There are 3 defects in type 2 diabetes that can be targeted by oral agents:
- Insulin resistance: In essence, the body is unable to use insulin effectively. I explain in the above link "it is as if there aren't enough doors on the cell wall, or the doors are stuck, or the lock has been changed, or else once the glucose gets into the cell it doesn't know what to do.
- Increased glucose production by the liver: Usually, as soon as you begin eating, insulin tells the liver to "shut its door" and to quit releasing glucose, since you can now get glucose from the food you're eating. With diabetes, the liver doesn't shut off, so it continues to produce unnecessary glucose.
- Decreased insulin production: Eventually, as diabetes progresses, the pancreas loses its ability to produce enough insulin-either it is delayed in releasing insulin, or it can't make enough-affectionately called a "pooped out pancreas."
So what does Glucophage do?
Glucophage (generic name is Metformin) targets defect #2: it suppresses the liver from making too much glucose. Because it does not stimulate the pancreas to produce insulin, it usually cannot cause hypoglycemia (low blood glucose) if you are only taking Glucophage. Glucophage can also help to lower your blood fats, decrease insulin resistance, and sometimes help with weight loss. While Glucophage is generally taken twice a day, Glucophage XR is the extended release, so it is usually taken only once a day, although sometime it is also given twice a day. An article in the September 2001 journal Practical Diabetology made several comments about Glucophage XR:
- There are fewer GI problems with Glucophage XR (i.e. less nausea, stomach upset, and diarrhea).
- The author had some concern that fewer stomach upsets might mean more calories ingested, more weight gain, and a poorer lipid profile, although this has not been proven.
- While the XR version is supposed to be effective when given once daily, the package insert reported a better decrease of the A1C in patients using Glucophage twice daily rather than the XR version once daily.
Before you get confused about all this, I must emphasize it has been my experience that each person with diabetes is a little different, so each situation needs to be evaluated individually. Some people do fine taking Glucophage XR once daily, while others may need to take it twice daily.
However, because of the way Glucophage works, it is unusual and not typically recommended to vary the dose the way you do, based on your food intake. Generally, adjusting oral medications based on carbohydrate intake or exercise is something that is only done if you are taking a sulfonylurea, meglitinide, or insulin.
More information about Glucophage:
While this drug is very popular and effective for many people, it is important to follow your doctor's directions about how to take it, as well as to note the possible side effects, mentioned in these links. There are precautions you need to be aware of, such as avoiding this drug if you: have kidney or liver problems; have heart failure; drink excess alcohol; are severely dehydrated; are going to have surgery or an x-ray procedure with an injection of dye; develop a serious medical condition, such as a heart attack, stroke, or severe infection; haven't had your kidney function checked.
So again, after you have reviewed all this information, be sure to discuss your situation with your diabetes team to obtain advice on your particular dosage requirements.
Related Questions
Insulin Resistance
Q:
"Could you explain insulin resistance so that I can understand it? This
term seems confusing to me."
Related Links
American Diabetes Association (ADA)
http://www.diabetes.org
National Diabetes Information Clearinghouse (NDIC)
http://diabetes.niddk.nih.gov
Bristol-Myers Squibb Company: "GLUCOPHAGE® (metformin hydrochloride
tablets)"
http://www.glucophagexr.com
Important Notice: The responses provided by the team of Diabetes Educators are based on their personal experiences and expertise as practicing diabetes healthcare professionals, and are not to be considered diabetes management advice from Abbott Laboratories. Remember that information provided by the team of Diabetes Educators is for general background purposes and is not intended as a substitute for medical diagnosis or treatment by a trained professional. You should always consult your physician about any healthcare questions you may have, especially before trying a new medication, diet, fitness program, or approach to healthcare issues.
All tradenames and trademarks not owned by Abbott Laboratories are the property of their respective owners. For details on tradenames and trademarks and their respective owners, visit the non-Abbott trademarks listing.
