SGLT2 Inhibitors and Fournier’s Gangrene: What You Need to Know Now
Fournier's Gangrene Symptom Checker
Critical Warning
Fournier's gangrene is a rare but rapidly progressing infection that requires immediate medical attention. If you're taking SGLT2 inhibitors and experience ANY of the symptoms below, go to the emergency room NOW.
Symptom Checklist
Check all symptoms you are experiencing. If ANY symptom is present, seek emergency care immediately.
When you're managing type 2 diabetes, taking a medication like SGLT2 inhibitors can feel like a win. They help lower blood sugar, protect your heart, and slow kidney damage. But there’s a rare, dangerous side effect you need to know about-Fournier’s gangrene. It’s not common. But when it happens, it moves fast. And if you don’t act right away, it can be deadly.
What Are SGLT2 Inhibitors?
SGLT2 inhibitors are a class of diabetes medications that work by making your kidneys flush out extra sugar through urine. That’s how they lower blood sugar. Common brands include Canagliflozin (a medication used to treat type 2 diabetes by blocking glucose reabsorption in the kidneys Invokana), Dapagliflozin (a sodium-glucose cotransporter-2 inhibitor that reduces blood glucose levels by increasing urinary glucose excretion Farxiga), Empagliflozin (an SGLT2 inhibitor shown to reduce cardiovascular death and hospitalization for heart failure in patients with type 2 diabetes Jardiance), and Ertugliflozin (a newer SGLT2 inhibitor approved for type 2 diabetes management Steglatro).
These drugs are not new. The first one, canagliflozin, got FDA approval in 2013. Since then, millions of people have used them safely. But around 2018, doctors started seeing something unusual: cases of a rare, aggressive infection called Fournier’s gangrene in people taking these medications.
What Is Fournier’s Gangrene?
Fournier’s gangrene is a type of necrotizing fasciitis. That means it’s a bacterial infection that kills soft tissue-fast. It usually starts in the genital or anal area. The bacteria eat through skin, fat, and muscle. It doesn’t wait. It spreads in hours, not days.
It’s rare. But it’s deadly. About 4 to 8% of people who get it die-even with treatment. And it’s not just men. While most cases happen in men, about one-third of reported cases in Europe were in women. That’s important. If you’re taking an SGLT2 inhibitor and you’re a woman, you’re not immune.
Why Do SGLT2 Inhibitors Increase the Risk?
The reason isn’t fully understood, but scientists have strong clues. SGLT2 inhibitors make your urine full of sugar. That’s how they work. But that sugar doesn’t just disappear. It stays in the area around your genitals and urethra. Bacteria love sugar. So they grow faster. More bacteria means more chance of infection.
There’s also a second issue: high glucose in urine can irritate skin and weaken tissue. Add that to the fact that many people taking these drugs also have poorly controlled diabetes-and diabetes already weakens your immune system-and you’ve got a perfect storm.
Studies show that 11 out of 12 early reported cases involved patients with HbA1c levels above 9%. That’s not a coincidence. Poor blood sugar control makes you more vulnerable.
Early Warning Signs You Can’t Ignore
This isn’t a rash. It’s not a yeast infection. It’s not something you can wait on. If you’re on an SGLT2 inhibitor and you notice any of these symptoms, go to the ER now:
- Severe pain or tenderness in your genitals, anus, or inner thighs
- Redness, swelling, or warmth in the area that spreads quickly
- Skin that looks bruised, black, or necrotic (dead)
- Fever, chills, or feeling extremely unwell
- Foul-smelling discharge from the genital area
- Difficulty urinating or painful urination
These symptoms can start mildly-maybe just a little soreness-and then explode within 12 to 24 hours. One man in a 2022 case report went from mild discomfort to needing emergency surgery in less than 18 hours. He survived. But he lost skin and tissue. He could have died if he’d waited until morning.
What Happens If You Delay?
Time is tissue. And time is life.
Every hour you wait after symptoms start increases your risk of death by about 9%. That’s not a guess. That’s from a 2022 study in Cureus analyzing over 100 cases. The longer you wait, the more bacteria spread. The more tissue dies. The harder it becomes to save you.
Standard treatment is brutal but necessary: immediate antibiotics and emergency surgery to cut out all dead tissue. Sometimes, multiple surgeries are needed. Sometimes, patients lose genitals. Sometimes, they don’t survive.
And here’s the kicker: if you’re on an SGLT2 inhibitor, you must stop it immediately when FG is suspected. Keep taking it, and you’re feeding the infection.
Who’s at Highest Risk?
Not everyone on SGLT2 inhibitors will get this. The risk is low-about 1.9 cases per 100,000 people per year. But some people are more vulnerable:
- Men over 50
- People with HbA1c above 9%
- Those with a history of genital yeast infections or urinary tract infections
- People with obesity, poor hygiene, or immune suppression (like from steroids or chemotherapy)
- Anyone with peripheral neuropathy (nerve damage) who might not feel early pain
If you fit even one of these categories, talk to your doctor. Don’t panic. But do be alert.
What Should You Do If You’re Taking an SGLT2 Inhibitor?
Don’t stop your medication unless your doctor tells you to. The benefits for most people still outweigh the risks. These drugs reduce heart failure hospitalizations and kidney failure. They save lives.
But here’s what you should do:
- Ask your doctor if you’re at higher risk for Fournier’s gangrene.
- Get clear instructions on what symptoms to watch for-write them down.
- Keep your blood sugar under control. HbA1c below 7% is ideal.
- Practice good hygiene. Wash daily, dry thoroughly, change underwear regularly.
- Don’t ignore genital itching, pain, or redness-even if you think it’s "just a yeast infection."
- If you have symptoms, go to the ER immediately. Say: "I’m on an SGLT2 inhibitor and I think I might have Fournier’s gangrene." That gets you prioritized.
What Do Health Agencies Say?
The FDA added a boxed warning to all SGLT2 inhibitor labels in 2018-the strongest warning they give. The European Medicines Agency and the UK’s MHRA did the same. All of them say: this is a class-wide risk. It’s not just one drug. It’s all of them.
And they’re still watching. The FDA’s Adverse Event Reporting System and the EU’s EudraVigilance database are still collecting new cases. As of 2024, the number of reported cases has risen since 2018. That doesn’t mean the risk got worse. It means doctors are better at recognizing it.
What’s Next?
Researchers are working on tools to predict who’s most at risk. Future guidelines may include checking for past genital infections or HbA1c levels before prescribing SGLT2 inhibitors. But for now, the message is simple: know the signs. Act fast.
For most people, SGLT2 inhibitors are a lifesaver. But for a very few, they can trigger something terrifying. Awareness isn’t fear. It’s power. And knowing what to look for could save your life-or someone you love.
Can women get Fournier’s gangrene from SGLT2 inhibitors?
Yes. While Fournier’s gangrene was once thought to affect only men, about one-third of reported cases in Europe involved women. SGLT2 inhibitors can increase the risk in anyone who uses them, regardless of gender. Women should watch for genital pain, swelling, redness, or fever and seek emergency care immediately if symptoms appear.
Should I stop taking my SGLT2 inhibitor because of this risk?
No-not unless your doctor advises it. The risk of Fournier’s gangrene is very low (about 1 in 50,000 per year), while the benefits-reduced heart failure, kidney protection, and better blood sugar control-are well proven. Stopping your medication without medical guidance can be more dangerous than the rare side effect.
How quickly does Fournier’s gangrene develop?
It can develop in as little as 12 to 24 hours. Symptoms often start as mild pain or redness, then rapidly worsen. Fever, swelling, and tissue death can follow within hours. Delaying treatment beyond 24 hours significantly increases the chance of death.
Is this side effect listed on the drug label?
Yes. Since 2018, the U.S. FDA, European Medicines Agency, and UK MHRA have all required a boxed warning-the strongest safety alert-on all SGLT2 inhibitor labels. The warning specifically mentions Fournier’s gangrene as a rare but life-threatening risk.
What should I do if I notice symptoms?
Go to the emergency room immediately. Do not wait. Call ahead if you can and say: "I’m on an SGLT2 inhibitor and I have symptoms of possible Fournier’s gangrene." Bring your medication list. You will need urgent antibiotics and surgical evaluation. Time is critical.
Final Thoughts
You’re not alone in worrying about this. But you’re not powerless, either. Knowledge is your best tool. Talk to your doctor. Know your symptoms. Keep your blood sugar in check. And if something feels wrong-don’t wait. Go. Because when it comes to Fournier’s gangrene, seconds matter more than hours, and hours matter more than days.