Aug. 30, 2018 -- The FDA is warning about rare cases of necrotizing fasciitis -- sometimes called “flesh-eating bacteria” -- of the genitals and genital area in patients taking type 2 diabetes drugs known as SGLT2 inhibitors.
The new warning will be added to the prescribing information and the patient medication guides for all types of the drugs and drug combinations approved to treat type 2 diabetes. They include:
- Canagliflozin (Invokana, Invokamet, Invokamet XR)
- Dapagliflozin (Farxiga, Xigduo XR, Qtern)
- Empagliflozin (Jardiance, Glyxambi, Synjardy, Synjardy XR)
- Ertugliflozin (Steglatro, Segluromet, Steglujan)
Necrotizing fasciitis of the genital area, also called Fournier's gangrene, is a life-threatening bacterial infection of the tissues under the skin surrounding the muscles, nerves, fat, and blood vessel in the genital area. It is estimated to happen to about 1.6 of 100,000 men annually in the United States, most often among those ages 50 to 79.
But from March 2013 to May 2018, the FDA received reports of 12 cases of Fournier's gangrene among patients taking SGLT2 inhibitors, of whom five were women and seven were men. The condition has rarely been reported among women. The patients ranged from 38 to 78 years old.
The condition developed an average of 9.2 months after the patients starting taking the drug. (Though the development time ranged from 7 days to 25 months.) Patients stopped taking the drug in most cases.
Multiple Surgeries, One Death
Reports included all SGLT2 drugs except ertugliflozin, but it "would be expected to have the same risk for this rare and serious infection as other SGLT2 inhibitors," the FDA said in a statement.
All 12 patients were hospitalized and required surgery to remove infected tissue. Five required more than one surgery, and one required skin grafting. Four patients developed complications, including diabetic ketoacidosis, acute kidney injury, and septic shock. One patient died, and two were transferred to a rehabilitation hospital.
Because diabetes makes Fournier's gangrene more likely, data were examined for patients taking other drugs that lower blood sugar. Between 1984 and 2018, just six cases of Fournier's gangrene were identified, all in men.
In 2017, an estimated 1.7 million patients received a prescription for an SGLT2 inhibitor from U.S. outpatient retail pharmacies.
Patients taking the drugs should seek medical help immediately if they have tenderness, redness, or swelling of the genitals or the genital area and have a temperature higher than 100.4 F.
The infection can get worse quickly, so patients are advised to get help right away.
The condition is treated with broad-spectrum antibiotics and surgery if needed. Patients should stop taking the drug and take other medications to control their blood sugar while monitoring their glucose levels.
The FDA urges patients to report any side effects from taking these or other drugs to FDA MedWatch by calling 855-543-DRUG (3784) and pressing 4; emailing [email protected]; or completing an online form.