The drugs belong to a class known as SGLT2 inhibitors that work by causing blood sugar to be secreted in the urine. They include AstraZeneca's Farxiga (dapagliflozin), J&J's Invokana (canagliflozin) and Jardiance (embagliflozin) from Lilly and Boehringer.
The FDA, in a warning on its website, said the medicines may lead to ketoacidosis, a serious condition where the body produces high levels of blood acids called ketones.
The FDA said its Adverse Event Reporting System database identified 20 cases of acidosis reported as diabetic ketoacidosis, ketoacidosis, or ketosis in patients treated with SGLT2 inhibitors between March 2013 to June 6, 2014. It said all patients required emergency room visits or hospitalization to treat the condition.
Since June 2014, the agency said it had continued to receive additional adverse event reports of diabetic ketoacidosis and ketoacidosis in patients treated with SGLT2 inhibitors.
The FDA warning also listed three combination type 2 diabetes treatments that include an SGLT2 drug as one of its two components, J&J's Invokamet, Xigduo XR from AstraZeneca and Lilly and Boehringer's Glyxambi.