This transcript has been edited for clarity.
I’m going to tell you the story of two patients with diabetes who had false-positive alcohol tests.
The first patient is a patient of mine with type 1 diabetes. He was in a car accident. He hit the car in front of him that hit the car in front of them. Because the cars were quite damaged, the police were summoned.
At the scene, he had a breathalyzer test. He flunked the breathalyzer test, and he was charged with a DUI. The woman in the middle car got out of her car and said her neck hurt. This then rose this to the level of a DUI with injury to one of the other people, and my patient was charged with a felony. He was taken to jail.
He told them at the scene and at the jail that he had type 1 diabetes. The reason this is so important is because type 1 diabetes can cause a false-positive breathalyzer test. In particular, this patient of mine had not been eating all day long. He’d been getting his basal insulin through the pump, but he had not given any bolus doses of insulin. He was actually quite ketotic.
When he was put in jail, they took away his cell phone so he could no longer see his glucose levels, and they took away the controller for his Omnipod system. He basically had no way to give bolus doses of insulin. Fortunately, the Omnipod system lasted for a day and a half just by giving him basal. The jail physicians did not give him insulin until he’d been in jail for 3 days.
This is someone with type 1 diabetes, and their protocol for insulin has something to do with high glucose levels and giving something like a sliding scale of insulin. They were not really prepared for managing somebody with type 1 diabetes who was on an automated insulin delivery system.
I, along with my patient’s parents, worked very hard to get the jail doctors to finally give him Lantus. Inherent in all of this, it made me aware of a number of different issues. The first is that breathalyzer tests can be falsely positive in people with type 1 diabetes if they are ketotic; therefore, people with type 1 diabetes should ask for a blood test to test their alcohol levels if they think it could be a false positive.
Second, we need to actually figure out a way to help people with type 1 diabetes who happen to be in jail or in prison because if they don’t have access to a smartphone, they’re not going to be able to run their devices. We need to make sure that devices have receivers that can be used, particularly continuous glucose monitors (CGMs), because CGM is the standard of care for patients and should be so for people who are incarcerated.
The second case is much shorter and isn’t mine, but it was a letter in The New England Journal of Medicine about a man who was on probation, who was having urine tests to show that he had not been consuming alcohol. He was started on empagliflozin, which, interestingly, made his urine test become falsely positive.
Why? Well, it’s thought it’s because it caused fermentation of the sugar with the bacteria that was in his urine because the people who were processing the sample hadn’t done it correctly, and they kept it out at room temperature for a prolonged period of time before testing it. The urine samples should be kept refrigerated to prevent this from happening.
These are two people who had false-positive tests because they had diabetes. I think it’s important that we realize that this can happen, and we need to help our patients deal with these situations.
Dr. Peters is professor, Department of Clinical Medicine, Keck School of Medicine; Director, University of Southern California Westside Center for Diabetes, University of Southern California, Los Angeles. She reported conflicts of interest with Abbott Diabetes Care, Becton Dickinson, Boehringer Ingelheim, Eli Lilly, Lexicon Pharmaceuticals, Livongo, Medscape, Merck, Novo Nordisk, Omada Health, OptumHealth, Sanofi, Zafgen, Dexcom, MannKind, and AstraZeneca.
A version of this article first appeared on Medscape.com.