US FDA warns of rare flesh-eating genital infection linked to certain diabetes drugs

SILVER SPRING, MARYLAND (REUTERS, BLOOMBERG) - The US Food and Drug Administration (FDA) said on Wednesday (Aug 29) that a serious genital infection has been reported in patients taking a certain class of diabetes drugs, leaving one dead and 11 others hospitalised.

The warning pertains to a class of medicines called SGLT2 inhibitors, first approved in 2013 to lower blood sugar in adults with type 2 diabetes.

The US health regulator has also called for including this risk in the drugs' labelling.

The drugs help the body lower blood-sugar levels via the kidneys, and excess sugar is excreted in a patient's urine. Urinary tract infections are a known side effect.

The SGLT2 inhibitors approved by the FDA include Johnson & Johnson's Invokana, Eli Lilly & Co's Jardiance, as well those from Bristol-Myers Squibb, AstraZeneca Plc, Merck & Co and Pfizer Inc.

The companies did not immediately respond to Reuters request for comment.

AstraZeneca told Bloomberg it is working with the agency on updating the label and noted that it had not seen any cases of the condition during the development of the drug Farxiga.

Patients are at risk of the infection known as Fournier's gangrene, an extremely rare but life-threatening bacterial infection of the tissue under the skin that surrounds the genital area, the FDA said in a statement.

The bacteria usually enter the body through a cut and quickly spread.

Having diabetes is a risk factor for developing Fournier's gangrene.

The FDA said it identified 12 cases of Fournier's gangrene - 7 in men and 5 in women - between March 2013 and May 2018.

One patient died, while some required multiple disfiguring operations and developed complications, the agency said.

The infection developed within several months of the patients starting an SGLT2 inhibitor and the drug was stopped in most cases, the FDA said.

Diabetics using the drugs should seek immediate medical attention if they develop tenderness, redness or swelling of the genitals, and if they have even a slight fever of 38 deg C, the agency said.

The symptoms can worsen quickly, so it is important to get help immediately, the drug agency added.

The drugs are expected to generate as much as US$7.1 billion (S$9.7 billion)  in sales by 2020, according to Bloomberg Intelligence.

The FDA estimates about 1.7 million patients got a prescription for one of the medicines from a retail pharmacy in 2017, underscoring how rare the condition is.