Bacitracin

Summary

Bacitracin is a cyclic polypeptide antibiotic derived from Bacillus subtilis, primarily active against gram-positive bacteria. It is widely used topically (often in combination with neomycin and polymyxin B) for prevention and treatment of minor skin infections. Systemic (intramuscular) use is limited due to nephrotoxicity. It is also used in ophthalmology and, historically, as a livestock growth promoter.

Mechanism of Action

Inhibits bacterial cell wall synthesis by binding to undecaprenyl pyrophosphate (C55-PP), preventing its dephosphorylation and recycling, thereby blocking peptidoglycan synthesis; also disrupts bacterial cell membrane integrity

Routes of Administration

Goals & Uses

• Treatment of superficial skin infectionsAntimicrobialHigh
• Clostridium difficile infection (oral)Antimicrobial / GILow
• Systemic gram-positive infections (IM)Antimicrobial / SystemicLow
• Prevention of minor skin infectionAntimicrobial / Wound CareHigh
• Ophthalmic infections (conjunctivitis, blepharitis)Antimicrobial / OphthalmologyModerate

Contraindications

• Deep wounds, puncture wounds, or serious burns (OTC topical)Wound TypeModerate
• Known hypersensitivity to bacitracinAllergyHigh
• Renal impairment (systemic/IM use)RenalHigh

Adverse Effects

• AnaphylaxisImmunologicRareSevere life-threatening allergic reaction
• Contact dermatitis / Allergic sensitizationDermatologic / ImmunologicUncommon
• Nausea and vomitingGastrointestinalUncommon
• Local injection site painLocal ReactionCommon
• Neuromuscular blockadeNeuromuscularRare
• NephrotoxicityRenalCommon

Drug Interactions

• Colistin / PolymyxinsModerate
• Neuromuscular blocking agents (e.g., succinylcholine, vecuronium)High
• Other nephrotoxic agents (e.g., aminoglycosides, vancomycin, NSAIDs)High

Population Constraints

• PregnancyReproductive SafetyRelative
• Neonates (systemic use)PediatricRelative
• Patients with renal impairmentOrgan ImpairmentAbsolute
• Large surface area applicationSpecial UseRelative

Regulatory Status

• European UnionApprovedApproved: Topical skin infections, Ophthalmic infectionsApproved in some EU member states for topical/ophthalmic use. Banned as a veterinary growth promoter since 1999.
• United StatesApprovedApproved: Topical treatment and prevention of minor skin infections, Ophthalmic infections (superficial), Systemic infections due to susceptible gram-positive organisms (IM, limited use)OTC for topical/ophthalmic; IM formulation is prescription-only. FDA has noted limited clinical evidence for OTC topical efficacy compared to plain petrolatum.
• United KingdomApprovedApproved: Topical skin and wound infections, Ophthalmic infectionsAvailable OTC and as prescription topical/ophthalmic preparations in the UK.

FDA-approved for topical and ophthalmic use OTC; intramuscular formulation is prescription-only and rarely used due to nephrotoxicity risk. Banned as a livestock feed additive in the EU. WHO classifies bacitracin as 'not critically important' for human medicine.

Evidence & Sources

No sources recorded yet.