The U.S. Food and Drug Administration issued a warning on Friday that a widely used new class of type 2 diabetes drugs may cause high levels of blood acids dangerous enough to put people in the emergency room. The new drugs are currently sold by major pharmaceutical companies, Astra Zeneca, Johnson & Johnson, and Eli Lilly who are in partnership with Boehringer Ingleheim.

The new class of type 2 diabetes drugs are a new group of oral medications called SGLT2 inhibitors. SGLT2 stands for sodium-glucose co-transporter-2. The drugs work by helping the kidneys to lower blood glucose levels and causing blood sugar to be secreted in the urine. What they do is prevent the kidneys from reabsorbing glucose back into the blood. This allows the kidneys to lower blood glucose levels and any excess glucose in the blood is excreted from the body through urination. SGLT2 inhibitors may also help people lose weight.

SGLT2 inhibitors include AstraZeneca's Farxiga (dapagliflozin), J&J's Invokana (canagliflozin) and Jardiance (embagliflozin) from Eli Lilly and Boehringer.

SGLT2 inhibitors are recommended for people with type 2 diabetes that have high blood glucose levels regardless of being on medications like metformin and insulin. However, there are certain side effects that are potentially dangerous. The FDA says the drugs may cause diabetic ketoacidosis. Additional side effects include genital and urinary tract infections, hypoglycemia, and possibly liver damage, breast cancer and bladder cancer. However, these long term side effects have only been studied in clinical trials and are not yet confirmed. 

The FDA found out in last year about 20 patients ended up in emergency room due to diabetic ketoacidosis. Diabetic ketoacidosis is a serious condition that causes the body to produce high levels of blood acids called ketones. The condition occurs when your body is not able to produce enough insulin. Insulin normally helps glucose enter our body’s cell. Without the right amount of insulin, the body starts to break down fat as an alternate fuel source for insulin. This in turn causes a buildup of toxic acids in the blood called ketones. If left untreated, this eventually leads to diabetic ketoacidosis.

Under normal circumstances, those at highest risk for diabetic ketoacidosis include people who have type 1 diabetes, are younger than age 19, and frequently miss insulin doses. Diabetic ketoacidosis can also occur in people who have type 2 diabetes, although it is less common.