Your Prescription Says Bacitracin/Polymyxin B — But the Pharmacy Says "Out of Stock"

If your doctor prescribed Bacitracin/Polymyxin B ophthalmic ointment and you can't find it at your pharmacy, you're dealing with a frustration shared by patients nationwide. The ongoing shortage has left many people searching for alternatives — and the good news is that several effective options exist.

In this guide, we'll explain what Bacitracin/Polymyxin B does, how it works, and walk you through the best alternative medications your doctor might prescribe instead.

What Is Bacitracin/Polymyxin B?

Bacitracin/Polymyxin B (brand names: Polysporin Ophthalmic, AK-Poly-Bac, Polycin) is a combination antibiotic ointment prescribed for bacterial eye infections. It's used to treat conditions like:

• Bacterial conjunctivitis (pink eye caused by bacteria)
• Blepharitis (inflammation of the eyelids)
• Keratitis (infection of the cornea)
• Blepharoconjunctivitis (combined eyelid and eye surface infection)

The ointment comes as a 3.5-gram tube and is typically applied to the lower eyelid every 3 to 4 hours for 7 to 10 days. For more details, see our complete guide on what Bacitracin/Polymyxin B is and how to use it.

How Does Bacitracin/Polymyxin B Work?

This medication combines two antibiotics that attack bacteria in different ways:

• Bacitracin blocks bacteria from building their cell walls. Without intact cell walls, bacteria can't survive. It's especially effective against gram-positive bacteria like Staphylococcus aureus and Streptococcus species.
• Polymyxin B punches holes in bacterial cell membranes, causing the contents to leak out. It targets gram-negative bacteria like E. coli, Klebsiella, and Pseudomonas aeruginosa.

By combining these two mechanisms, Bacitracin/Polymyxin B covers a broad range of bacteria that commonly cause eye infections. Learn more in our article on how Bacitracin/Polymyxin B works.

Alternatives to Bacitracin/Polymyxin B

Important: Never switch medications on your own. Always talk to your doctor before using an alternative. They'll consider your specific infection, allergies, and medical history when recommending a substitute.

1. Erythromycin Ophthalmic Ointment

Erythromycin is one of the most widely available alternatives to Bacitracin/Polymyxin B. It's a macrolide antibiotic that works by stopping bacteria from making the proteins they need to grow.

Key facts:

• Used for: Bacterial conjunctivitis, prevention of neonatal eye infections
• How it's applied: Ointment applied to the lower eyelid, similar to Bacitracin/Polymyxin B
• Availability: Widely available as a generic; less affected by the current shortage
• Cost: Approximately $15-$30 with a discount coupon
• Pros: Safe for use in newborns and infants; well-tolerated; fewer allergy concerns
• Cons: Narrower spectrum — primarily covers gram-positive bacteria; may not be effective against gram-negative infections

2. Tobramycin Ophthalmic (Tobrex)

Tobramycin is an aminoglycoside antibiotic available as both eye drops and ointment. It's a strong option for infections involving gram-negative bacteria.

Key facts:

• Used for: Bacterial conjunctivitis, corneal ulcers, external eye infections
• How it's applied: Eye drops (every 4-6 hours) or ointment (2-3 times daily)
• Availability: Generally available as a generic
• Cost: Approximately $15-$40 with a discount coupon
• Pros: Excellent gram-negative coverage, including Pseudomonas; available in drop form for those who prefer drops over ointment
• Cons: Less effective against some gram-positive bacteria; potential for eye irritation

3. Ciprofloxacin Ophthalmic (Ciloxan)

Ciprofloxacin is a fluoroquinolone antibiotic with very broad coverage. It's often prescribed when doctors want to ensure they're covering as many bacterial types as possible.

Key facts:

• Used for: Bacterial conjunctivitis, corneal ulcers, more severe eye infections
• How it's applied: Eye drops (every 2-4 hours initially) or ointment
• Availability: Widely available as a generic
• Cost: Approximately $10-$30 with a discount coupon
• Pros: Very broad-spectrum coverage; effective against both gram-positive and gram-negative bacteria; available as drops and ointment
• Cons: May cause white crystalline deposits on the cornea (usually temporary); not recommended for children under 1 year

4. Neosporin Ophthalmic (Bacitracin/Neomycin/Polymyxin B)

This is a "triple antibiotic" ointment that contains the same two ingredients as Bacitracin/Polymyxin B plus an additional antibiotic — Neomycin. It provides slightly broader coverage but comes with more allergy risk.

Key facts:

• Used for: Bacterial conjunctivitis, blepharitis, keratitis
• How it's applied: Ointment applied to the lower eyelid, same as Bacitracin/Polymyxin B
• Availability: May also be affected by bacitracin supply issues
• Cost: Approximately $15-$35 with a discount coupon
• Pros: Broader coverage with three antibiotics; familiar application method
• Cons: Neomycin has a higher rate of causing allergic reactions (contact dermatitis); not ideal for patients with known antibiotic allergies

How to Decide Which Alternative Is Right for You

Your doctor will consider several factors when recommending an alternative:

• The type of infection: Some antibiotics are better for certain bacteria than others
• Your allergy history: If you're allergic to certain antibiotics, some alternatives may not be safe
• Severity of the infection: More serious infections like corneal ulcers may need broader-spectrum options like Ciprofloxacin
• Your preference for drops vs. ointment: Some alternatives are available in both forms
• Cost and availability: Your doctor can check what's in stock and affordable

For information on potential drug interactions with any of these alternatives, see our guide on Bacitracin/Polymyxin B drug interactions.

Still Want to Try Finding Bacitracin/Polymyxin B?

If you and your doctor prefer the original prescription, don't give up entirely. Some pharmacies still have limited stock. Use Medfinder to search for pharmacies that have it available. You can also read our guide on how to find Bacitracin/Polymyxin B in stock near you for more strategies.

Final Thoughts

While the Bacitracin/Polymyxin B shortage is frustrating, it's important to remember that your eye infection still needs treatment. Several effective alternatives are available, and your doctor can help you choose the best one for your situation. Whether it's Erythromycin, Tobramycin, Ciprofloxacin, or Neosporin Ophthalmic, you have options.

The most important thing is not to delay treatment. Untreated bacterial eye infections can worsen and, in rare cases, lead to vision problems. Talk to your doctor today about the best path forward.