FDA warns against DIY insulin systems, citing overdose report

Earlier this year, the FDA created a new regulatory pathway for interoperable infusion pumps that can be paired with a compatible insulin dosing system or monitor. (Andrew Harnik, Associated Press)

The FDA is warning patients with diabetes against using homegrown treatment devices such as combinations of glucose monitoring systems, insulin pumps or dosing systems that are not recognized by the agency.

Some patients have opted for the “do-it-yourself” route compared to the higher prices of fully FDA-approved platforms—which can include components that may not be interoperable or interchangeable, thus requiring them all to be bought from a single manufacturer.

However, the agency said it is concerned patients might not fully understand the risks of programming the devices incorrectly or of potentially inaccurate blood sugar readings, as well as unsafe insulin levels that can lead to severe injuries including diabetic ketoacidosis, coma or death.

“The FDA is aware that patients may choose to create these systems or purchase unauthorized or unapproved components or systems because of personal preference or for cost reasons,” the agency said in a statement.

“The agency has received a report of a serious adverse event in which a patient’s use of an illegally marketed continuous glucose monitoring (CGM) system along with an unauthorized automated insulin dosing system resulted in insulin overdose requiring medical attention.”

RELATED: FDA approves Medtronic's 'artificial pancreas,' the world's first

Late last month, The Atlantic published an article exploring the underground market of obsolete and discontinued insulin pumps that has grown since 2014, including several models from Medtronic made valuable again for their ability to be reprogrammed with open-source software for homemade use. The software allows the pumps to be paired with a separate glucose monitor, creating a loop where insulin is automatically delivered or withheld based on blood sugar levels and user feedback.

In a not-so-subtle warning to those developers, the FDA said it is aware of “manufacturers illegally marketing unauthorized devices for diabetes management” as well as components “such as unauthorized continuous glucose monitors that some patients may integrate into unauthorized automated insulin dosing systems.”

RELATED: FDA grants de novo clearance to Tandem’s plug-and-play insulin pump

The first “artificial pancreas” looping system was approved by the FDA in 2016—Medtronic’s MiniMed 670G pump, patch and sensor—and is designed to manage insulin levels with little input from the patient. The system currently retails for about $8,000 before insurance.

“The FDA recommends that patients talk with their doctor about appropriate diabetes management devices for their needs and to only use devices and components that have been reviewed by the agency for safety and effectiveness,” the agency said. “Patients who are concerned about the cost or availability of FDA-reviewed systems, should talk with their doctor and insurance provider about coverage and appropriate alternative options.”

The agency also said it recognizes that patients prefer to have multiple, customizable treatment options, and has been working to review interoperable pumps and implantable CGM systems.

Earlier this year, the FDA cleared Tandem Diabetes Care’s t:Slim X2 pump, described as the first in a new category of interoperable hardware called alternate controller-enabled infusion, or ACE, pumps. These devices can allow patients to link their preferred devices including compatible automated dosing systems, CGMs and blood sugar meters.

With the de novo clearance, the FDA established new special control criteria outlining the requirements for accuracy, reliability, cybersecurity and clinical relevance of ACE infusion pumps, as well as the types of studies and data required.