Bacitracin topical - Drug Monograph

Introduction

Bacitracin topical is an antibiotic preparation used for the prevention and treatment of superficial skin infections. It belongs to the polypeptide class of antibiotics and has been widely used in dermatological practice since its discovery in 1945. This monograph provides comprehensive information about bacitracin topical for healthcare professionals and patients.

Mechanism of Action

Bacitracin exerts its antibacterial effect by interfering with bacterial cell wall synthesis. Specifically, it inhibits the dephosphorylation of the lipid carrier (undecaprenyl pyrophosphate) that transports peptidoglycan precursors across the cytoplasmic membrane. This disruption prevents the incorporation of these precursors into the growing peptidoglycan chain, ultimately leading to bacterial cell death. Bacitracin is primarily bactericidal against Gram-positive organisms, including staphylococci and streptococci, with minimal activity against Gram-negative bacteria.

Indications

FDA-approved indications:

• Prevention and treatment of superficial skin infections caused by susceptible organisms
• Prophylaxis against infection in minor cuts, scrapes, and burns

Common off-label uses:

• Secondary infection in dermatological conditions such as eczema
• Post-procedural wound care
• Prevention of infection in superficial abrasions

Dosage and Administration

• Apply a thin layer to affected area 1-3 times daily
• Cover with sterile bandage if desired

• Clean affected area thoroughly before application
• Use sterile applicator or clean hands to apply
• Duration typically ranges from 7-10 days or until healing occurs

• Pediatric use: Generally considered safe with appropriate supervision
• Geriatric use: No dosage adjustment required
• Renal impairment: Minimal systemic absorption; no adjustment needed
• Hepatic impairment: No specific recommendations

Pharmacokinetics

Contraindications

• Hypersensitivity to bacitracin or any component of the formulation
• History of contact dermatitis to bacitracin
• Use in deep puncture wounds or serious burns
• Application to large surface areas with compromised skin integrity

Warnings and Precautions

• Risk of contact dermatitis with prolonged use (reported in 1-10% of users)
• Not for ophthalmic use unless specifically formulated for ocular application
• Superinfection may occur with prolonged use
• Avoid use in patients with history of allergic reactions to polypeptide antibiotics
• Use caution in patients with renal impairment when applied to large areas of damaged skin

Drug Interactions

• No clinically significant pharmacokinetic interactions documented
• Potential for reduced efficacy when used concomitantly with cationic compounds
• Theoretical interaction with neuromuscular blocking agents (though unlikely with topical use)

Adverse Effects

• Localized irritation
• Pruritus at application site
• Mild burning sensation
• Contact dermatitis

• Anaphylaxis (rare)
• Severe contact dermatitis
• Superinfection with resistant organisms
• Systemic effects with large-area application (nephrotoxicity)

Monitoring Parameters

• Wound healing progress
• Signs of local irritation or hypersensitivity
• Evidence of superinfection
• Renal function if applied to extensive areas of damaged skin
• Therapeutic response after 3-5 days of use

Patient Education

• Use only as directed for minor skin infections
• Clean wound thoroughly before application
• Apply thin layer and cover with bandage if desired
• Discontinue use and contact healthcare provider if:

- Condition worsens or doesn't improve within 3-5 days - Rash, itching, or severe irritation develops - Signs of allergic reaction appear (swelling, difficulty breathing)

• Avoid contact with eyes, nose, and mouth
• Do not use on deep wounds, animal bites, or serious burns
• Complete full course of treatment even if symptoms improve
• Store at room temperature away from moisture

References

1. FDA Prescribing Information: Bacitracin Topical Ointment 2. Lexicomp Online: Bacitracin Monograph 3. Clinical Pharmacology [Internet]. Tampa (FL): Gold Standard, Inc.; 2023 4. Medscape Drug Reference: Bacitracin Topical 5. UpToDate: Topical antibiotics for skin and soft tissue infections 6. American Academy of Dermatology Guidelines for Topical Antimicrobial Use 7. Journal of the American Academy of Dermatology: Contact Dermatitis to Topical Antibiotics 8. Cochrane Database Systematic Review: Topical antibiotics for infected wounds