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What the FDA labels say about taking them together

Bacitracin and polymyxin b

Polymyxin b's FDA label of May 9, 2025 names bacitracin in its boxed warning section; the bacitracin label PlainMeds reads does not name polymyxin b.

Check it at the source: the bacitracin FDA label on DailyMed (effective August 24, 2026); the polymyxin b FDA label on DailyMed (effective May 9, 2025, Gland Pharma Limited).

What does the bacitracin label say about polymyxin b?

Bacitracin's label (effective August 24, 2026) does not name polymyxin b in these sections. A label lists what its studies and reports found; it is not a complete list.

Source: FDA drug label (Claravie), Gentell LLC, effective August 24, 2026 (SPL set 59c5a363-6d79-d07e-e063-6294a90a8753), via openFDA; the full label on DailyMed

What does the polymyxin b label say about bacitracin?

Polymyxin b label, boxed warning

THE CONCURRENT OR SEQUENTIAL USE OF OTHER NEUROTOXIC AND/OR NEPHROTOXIC DRUGS WITH POLYMYXIN B SULFATE, PARTICULARLY BACITRACIN, STREPTOMYCIN, NEOMYCIN, KANAMYCIN, GENTAMICIN, TOBRAMYCIN, AMIKACIN, CEPHALORIDINE, PAROMOMYCIN, VIOMYCIN, AND COLISTIN SHOULD BE AVOIDED.

Source: FDA drug label (POLYMYXIN B), Gland Pharma Limited, effective May 9, 2025 (SPL set dc74dee2-1d0b-4fab-a29b-1755fdb5da75), via openFDA; the full label on DailyMed

These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.

Both medicines on the record

0Bacitracin generic labelers
7Polymyxin b generic labelers
BacitracinPolymyxin b
Labeled forn/aBacterial infections, Urinary tract infections
Boxed warningNoYes
Pharmacy cost (NADAC)$0.0761 per gram 500 unit/g ointmntn/a
Shortage nowIn shortageNo current entry

Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)

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