Besifloxacin: What It Is, How It Works, and Where It's Used

When you have a red, gritty, or pus-filled eye, it’s often not just irritation—it’s a bacterial infection. That’s where besifloxacin, a prescription antibiotic eye drop specifically designed for eye infections. Also known as Baxdela, it’s one of the few fluoroquinolone antibiotics made just for the eye, not the body. Unlike oral antibiotics that circulate everywhere, besifloxacin stays local. It kills bacteria right where they’re causing trouble—on the surface of your eye.

Besifloxacin is a fluoroquinolone antibiotic, a class of drugs that stop bacteria from copying their DNA. That means it doesn’t just slow down the infection—it shuts it down fast. It works against common troublemakers like Staphylococcus aureus, a bacteria often responsible for styes and conjunctivitis, and Streptococcus pneumoniae, a leading cause of bacterial eye infections in adults and kids. It’s not a cure-all, though. It won’t touch viruses or allergies. But when your doctor says it’s bacterial, besifloxacin is often the go-to because it’s strong, targeted, and doesn’t need to be shaken up like older drops.

What makes besifloxacin stand out? It doesn’t rely on preservatives that can irritate sensitive eyes. That’s why it’s often chosen for people who’ve had bad reactions to other eye drops. It’s also used when other antibiotics fail—or when speed matters. Think post-surgery eyes, contact lens-related infections, or kids who won’t sit still for frequent dosing. With just three doses a day for a week, it’s simpler than older regimens that required eight doses.

You won’t find besifloxacin on a pharmacy shelf without a script. That’s because misuse of antibiotics—even in the eye—can lead to resistant strains. But when used right, it’s one of the most reliable tools doctors have for clearing up stubborn eye infections. It’s not for long-term use. Not for dry eyes. Not for pink eye caused by colds. But if your eye is swollen, yellow, and burning? It might be exactly what you need.

Below, you’ll find real-world guides on how besifloxacin fits into broader treatment plans, how it compares to other eye antibiotics, and what to watch for when using it. These aren’t just drug facts—they’re practical tips from people who’ve been there.