As a 75 year old male, I have been effectively using metformin to treat my type 2 diabetes for about a year with excellent results. My doctor has declined to renew my prescription because it is contraindicated by my creatinine level, which is at 1.4, where it has been over the last eight months.

My alternatives were given as:

Take a drug, glipizide, at a reduced dose that has caused hypoglycemia in the past.

Take insulin.

Treat by diet, which I do anyhow.

Based on your professional opinion, how appropriate is it for me to continue using metformin?

There are other options. I did not see the option of the use of drugs from the class known as thiozolidinediones and include either Actos or Avandia. These drugs can cause peripheral edema and may be contraindicated with a history of heart failure. Your physician is correct in the letter of the law. The FDA-approved drug label does say that metformin may not be used if the serum creatinine rises to 1.4 mg/dl. Some feel this is a gray area, but it is the letter of the law, as far as the FDA is concerned. The idea is that metformin use in renal insuffciency may predispose to a condition known as lactic acidosis and it may be life-threatening. I have done this myself in the management of other patients. As noted above, there are other agents that might be added to the group you indicated.

JTL