There are 17 pharmaceutical companies that make extended release Metformin. It seems that the way the extended release drug is made causes there to be what the FDA has called toxic levels of NDMA which has been associated with causing cancer. Regular Metformin, immediate release is not associated with toxic levels of NDMA and is fine to continue using. The biggest advantage of the extended release form is that it has less GI side effects such as gas, bloating and diarrhea. So, you may have some of that when you switch. Also the extended release is easier to take because of fewer dosages to cover 24 hours.
Metformin is a very important medication for treatment of Diabetes Type 2. It was the first medicine for the insulin resistance that causes high blood sugar in the most common type of Diabetes. High blood sugar is associated with complications of Diabetes of which I am sure you are all aware. Metformin reduces insulin resistance and is the base drug for most therapies for Type 2 Diabetes.
So, don’t stop your metformin and I am changing patients to immediate release metformin. Also there are alternative medicines if regular release metformin is not tolerated.
Finally this NDMA problem has complicated treatments for heartburn and ulcer patients and also for persons with high blood pressure and kidney disease.