Does Metformin Cause Lactic Acidosis?
Lactic acidosis refers to the build up of the acid 'lactate' (also known as lactic acid) in the blood. We all produce lactic acid when breaking down sugar at times of stress and when we exercise vigorously. In some circumstances, too much lactic acid can build up in the blood. This happens particularly in situations where there is not enough oxygen in the blood, or the kidneys are not filtering out lactic acid as they should be. Examples of these situations are kidney failure, heart attacks and severe lung problems. If lactic acid builds up, this changes the pH of the blood and can be very dangerous. Although lactic acidosis is rare, it happens occasionally to very sick patients regardless of what medicines they are taking. Why might metformin increase the risk of lactic acidosis? In the 1970s, a medication called phenformin was removed from the market. This was because it was found to significantly increase the risk of lactic acidosis. Metformin is in the same family as phenformin (they are both biguanides), so as you can imagine, people wondered whether it might also increase the risk of lactic acidosis. What are the facts? In 50 years of using metformin there have been only 330 Continue reading >>