Fluoroquinolones: What You Need to Know About This Antibiotic Class

When doctors prescribe fluoroquinolones, a class of broad-spectrum antibiotics used for serious bacterial infections. Also known as FQs, they include drugs like ciprofloxacin, levofloxacin, and moxifloxacin—commonly used for urinary tract infections, pneumonia, and sinus infections. But these drugs aren’t harmless. The FDA has issued multiple black box warnings because they can cause lasting harm, even after a short course.

One of the biggest risks tied to fluoroquinolones, a class of antibiotics with a high potential for severe adverse reactions is tendon rupture, a sudden, painful tear that can happen in the Achilles tendon or other tendons, even in healthy people. It can occur within hours or weeks after starting the drug. The risk goes up if you’re over 60, on steroids, or have kidney problems. Another serious concern is peripheral neuropathy, nerve damage that causes burning, tingling, or numbness, sometimes permanently. These aren’t rare side effects—they’re well-documented and serious enough that the FDA now says fluoroquinolones should only be used when no other options exist.

Fluoroquinolones also contribute to antibiotic resistance, the growing global crisis where bacteria evolve to survive drug treatment. Overuse—even for minor infections like bronchitis or ear infections—fuels this problem. That’s why guidelines now push doctors to avoid them unless absolutely necessary. You’ll also find in our collection that these drugs can interact with other medications, like blood thinners and antacids, and may trigger rare but deadly reactions like DRESS syndrome, a severe drug reaction with fever, rash, and organ damage. Even something as simple as sun exposure can turn into a dangerous burn while on these drugs.

There’s a reason you’re seeing more posts about fluoroquinolones here. They’re not just another antibiotic—they’re a cautionary tale in modern medicine. Our articles cover how to spot class-wide safety alerts, what to do if you’ve had a bad reaction, how they compare to safer alternatives, and why some patients end up with long-term pain or disability after just one prescription. If you’ve ever been prescribed one, or know someone who has, you need to understand the full picture—not just the benefit, but the real cost.