A recent report from the U.S. Food and Drug Administration (FDA) may be striking unnecessary fear in some people with diabetes.
In particular, it may be alarming patients who are taking diabetes medications in the class of “sodium-glucose cotransporter-2” (SGLT2) inhibitors.
Those drugs were approved for use in the United States in 2013. Brand names include Invokana, Invokamet, Jardiance, and Farxiga.
FDA officials say they have pinpointed a link between a “rare but serious” infection called Fournier’s gangrene within and around the genital area in people with diabetes taking these medications.
Designed to lower blood sugar, SGLT2 inhibitors help to remove excess glucose from the body by expelling that substance through the kidneys and then through a patient’s urine.
The drugs were initially formulated for use in patients with type 2 diabetes, but they have also proven effective in reducing blood glucose levels in patients with type 1 diabetes.
“Fournier’s gangrene is an extremely rare but life-threatening bacterial infection of the tissue under the skin that surrounds muscles, nerves, fat, and blood vessels of the perineum,” explains the FDA announcement. “The bacteria usually get into the body through a cut or break in the skin, where they quickly spread and destroy the tissue they infect.”
People with diabetes are at an increased risk of developing this type of infection, compared to those without diabetes, even if they aren’t taking an SGLT2 inhibitor.
That’s because excess glucose in the bloodstream and urine feeds infection and impairs the healing process of even small cuts or blisters.
However, experts emphasize how rare the likelihood is of a patient developing this infection by taking SGLT2 inhibitor medications.
“Seven cases out of 7 million prescriptions,” said Gary Scheiner, MS, CDE, founder of Integrated Diabetes Services, author of “Think Like a Pancreas,” and a 2014 diabetes educator of the year. “That makes it literally a one-in-a-million event.”
By the numbers
The FDA report explains that between March 2013 to May 2018, there were 12 cases of Fournier’s gangrene in patients taking a SGLT2 inhibitor medication.
“Fournier’s gangrene developed within several months of the patients starting an SGLT2 inhibitor and the drug was stopped in most cases,” the report states. “All 12 patients were hospitalized and required surgery. Some patients required multiple disfiguring surgeries, some developed complications, and one patient died.”
The report adds that in patients taking other diabetes medications, there have only been six cases of Fournier’s gangrene reported, all of which were in men, over the course of 30 years.
Of the 12 reported in this recent report, seven were men and five were women.
Scheiner adds that, Fournier’s gangrene aside, any medication purposefully passing glucose through the urine raises the risk for all types of infection, especially basic urinary tract infections (UTIs).
“Patients have to be on the lookout for signs of UTI and seek treatment. It should never get to a point as serious as gangrene,” Scheiner told Healthline. “It is incumbent on prescribing physicians to teach this to their patients.”
This is not, however, the first FDA warning when it comes to this class of drugs.
Over the past few years, cases of diabetic ketoacidosis (DKA) have been linked to the use of SGLT2 inhibitors.
DKA is a life-threatening condition in which the blood becomes too acidic, usually as a result of too little insulin present in the body. The ailment requires immediate hospitalization and intravenous saline and insulin to treat.
While the illness is rare, it’s imperative that people with diabetes taking SGLT2 inhibitors monitor ketone levels regularly during the first year or two of taking the drug.
A patient’s perspective
Many patients taking SGLT2 inhibitors report no unpleasant side effects aside from needing to drink more water and urinate more frequently.
“I’ve been on Invokana basically since it first hit the U.S. market in 2013,” Steven Kane, a 56-year-old patient with type 1 diabetes, told Healthline. “It’s been a very positive experience.”
While Kane is aware of the increased risk for DKA and infections, he says he’s only experienced the intended effects of the drug, including reduced blood glucose levels and reductions in his insulin doses.
“No ketones. No genital issues. I lost a bunch of weight at first. My basal insulin needs got reduced by 65 percent, and my bolus insulin for meals has reduced by 30 percent. My A1c is usually just under 7 percent, and I give myself a B+ or A- when it comes to my overall self-care,” he said.
Kane has no intentions of discontinuing his use of SGLT2 inhibitors, as they have become a helpful part of his overall diabetes management care.
“I watch what I eat and I pretty low carb, but I’m not on an particular diet or plan,” he said. “I don’t measure my portions. I’m a proud ice cream addict. I’m not overweight and I exercise regularly.”