The US Food and Drug Administration (FDA) has issued a Class I recall for the t:connect iOS mobile app, which is used to monitor and control the t:slim X2 insulin pump used by people with diabetes. It is believed to be the first smartphone app that can program FDA-approved insulin doses. The agency issued the highest possible recall because the app had serious software issues that could cause life-threatening conditions or even death. In fact, although no deaths have been reported, the FDA has received 224 reports of injuries as of April 15.

According to the agency, version 2.7 of the t:connect mobile app had a bug that initiated a cycle where the app would crash and then launch again and again from the iOS platform. This apparently resulted in excessive Bluetooth communication that would drain the pump’s battery and cause it to shut down sooner than the user would expect. Insulin pumps like the t:slim X2 are designed to automatically deliver insulin under the user’s skin at set intervals and when needed. They are supposed to take on the burden of managing the user’s sugar levels so they can get through their day without having to stop and inject themselves or if they are prone to hypo or hyperglycemia.

If the pump shuts off without warning and before the user expects it, it can cause insufficient insulin delivery. As the FDA explained in its recall, this can lead to hyperglycemia and even diabetic ketoacidosis, a life-threatening complication caused by the body’s inability to convert sugar into energy due to a lack of insulin. Tandem Diabetes Care, the company behind the app and pump, sent all affected customers an emergency notice back in March. He advised them to update their app, keep a close eye on their pump’s battery level and carry back-up supplies of insulin. The FDA recall notice may reach potentially affected customers who, however, may not have seen the manufacturer’s warning or who may have ignored it. There were faulty insulin pumps associated with multiple deaths in the past, so consumers may want to keep a close eye on theirs, regardless of brand.