Important Safety Alerts

Important Safety Alerts

Medical Device Safety Alert: Continuous glucose monitoring systems (CGMs), insulin pumps, or automated insulin dosing (AID) systems

20 May 2019

The United States Food and Drug Administration (FDA) is warning patients and health care professionals of risks associated with the use of unapproved or unauthorized devices for diabetes management, including continuous glucose monitoring systems, insulin pumps and automated insulin dosing systems.

The FDA received a report of a serious adverse event in which a patient used an unauthorized device that receives the electronic signal from an FDA authorized glucose sensor and converts it to a glucose value using an unauthorized algorithm. Glucose values from the unauthorized continuous glucose monitoring system were sent to an unauthorized automated insulin dosing device to drive insulin dosing. The automated insulin dosing system gave too much insulin in response to repeated incorrect high glucose values sent from the continuous glucose monitoring system. This unauthorized system resulted in an insulin overdose requiring medical intervention. These devices were not designed to be used together and were combined in a way that had not been thoroughly tested for compatibility. Based on the available information, it is unclear whether the insulin overdose resulted from inaccurate glucose values reported from the unauthorized sensor, or a software malfunction in the unauthorized automated insulin dosing system that misinterpreted the electronic signal from the unauthorized continuous glucose monitoring system.

Some diabetes management devices are authorized for sale in the U.S. by the FDA only in a specific configuration, while others are authorized for use with other compatible devices, which may include automated insulin dosing systems, insulin pumps, blood glucose meters or other devices used for diabetes management. For example, an authorized automated insulin dosing system will include a specific continuous glucose monitoring system, a specific insulin pump, and a specific algorithm. These devices are all tested and authorized together as a system.

The FDA has authorized diabetes devices that have been designed to work safely with other devices, such as integrated continuous glucose monitoring systems and "automated controller enabled" insulin pumps, that comprise diabetes therapy systems. This approach allows patients to safely tailor their diabetes management. Devices are labeled to indicate which compatible devices patients can safely use together as a system.

When patients combine devices that are not intended for use with other devices, or when patients use any unauthorized devices, new risks are introduced that the FDA has not evaluated for safety or effectiveness. Patient use of unauthorized diabetes management devices, alone or along with other devices, could result in inaccurate glucose level readings or unsafe insulin dosing. These inaccuracies may lead to injuries requiring medical intervention, such as severe low blood sugar, coma, diabetic ketoacidosis (buildup of acids in blood), and death.

In addition, the FDA is aware of manufacturers marketing unauthorized diabetes management devices that use an algorithm to convert raw data from an FDA authorized glucose sensor to a glucose level displayed to the patient. The FDA has not evaluated the algorithm that these unauthorized devices use. The algorithm may return inaccurate glucose values.

The FDA has provided recommendations for health care providers and people with diabetes.

For details, please refer to the following FDA websites:
https://www.fda.gov/medical-devices/2019-safety-communications/fda-warns-people-diabetes-and-health-care-providers-against-use-devices-diabetes-management-not
https://www.fda.gov/news-events/press-announcements/fda-warns-against-use-unauthorized-devices-diabetes-management

Posted on 20 May 2019

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