Glucophage® and Metformin Questions

BOSTON — May, 2002 — A study published this week in the Journal of the American Medical Association suggests that some physicians are inadequately informed about which patients can safely use the diabetes medication Glucophage® (metformin). As a result, they are, in some cases, prescribing the medication for individuals who should not be taking the medication because the patients already have heart, liver or kidney disease.

According to experts at Joslin Diabetes Center, this research does NOT suggest that Glucophage® (metformin) is dangerous in and of itself. Rather, the drug should not be prescribed to people with diabetes who also have significant heart, liver or kidney disease, because if used by these individuals it can result in a serious medical problem called lactic acidosis. Lactic acidosis is a buildup of lactic acid in the blood that is fatal in about 50 percent of cases. Patients with severe congestive heart disease or kidney failure are especially prone to this problem

Joslin has received phone calls from individuals with diabetes concerned that the medication causes health problems and wondering if they should immediately stop taking the drug. Here are the Center's recommendations.

1. No patient should stop taking the drug without consulting his or her physician first.

2. Patients concerned about this medication should contact their physician and ask the following questions:

• Do I have any evidence of kidney disease? Signs of kidney disease can include protein in the urine, including even small amounts of protein, or an elevated creatinine level. (The presence of small amounts of protein in the urine is not always a sign that the patient cannot use Glucophage® (metformin), as some people with some protein in the urine still have normal kidney function. It is the creatinine that is most important. You should discuss this with your doctor.)
• Do I have any signs of liver disease? Liver diseases include cirrhosis, hepatitis C, or abnormal liver function tests - MDs usually check these in patients. People who are heavy drinkers also should not take Glucophage® (metformin).
• Do I have any risks of heart failure, such as a prior heart attack, a history of congestive heart failure, angina, blood vessel blockage?
  If your doctor says that you have any of these conditions, let your doctor know that you are aware that it may not be appropriate to prescribe Glucophage® (metformin) to people with these conditions because of potential dangerous side effects. Ask your doctor what alternative medications he/she would suggest.