Mupirocin 2% Ointment for Nasal Septum Sores
Do not use the standard mupirocin 2% ointment (Bactroban topical) on nasal septum sores—the FDA explicitly states that mupirocin ointment is not formulated for use on mucosal surfaces, and a specialized paraffin-based intranasal formulation (Bactroban Nasal/mupirocin calcium ointment) exists specifically for intranasal use. 1
Critical Safety Distinction
The polyethylene glycol-based formulation of standard mupirocin 2% ointment poses specific risks when used intranasally:
- The FDA drug label clearly warns that mupirocin ointment is not formulated for mucosal surfaces 1
- Intranasal use of the standard polyethylene glycol-based formulation has been associated with stinging and drying 1
- Polyethylene glycol can be absorbed from damaged tissue (which a nasal septum sore represents) and is renally excreted, creating particular concern in patients with moderate to severe renal impairment 1
Appropriate Intranasal Formulation
If treating a nasal septum sore that is infected with Staphylococcus aureus or requires bacterial decolonization, use the specialized paraffin-based intranasal mupirocin calcium ointment (Bactroban Nasal), not the standard topical ointment. 1
The intranasal formulation protocol for bacterial infections or decolonization:
- Apply mupirocin calcium ointment (intranasal formulation) into each nostril twice daily 2
- Continue treatment for 5-7 days for optimal efficacy 2
- This regimen effectively eradicates Staphylococcus aureus nasal carriage in over 95% of cases 3
Clinical Context Matters
The appropriateness of any mupirocin formulation depends on the nature of the nasal septum sore:
- For bacterial infection (impetigo, folliculitis, or secondarily infected lesions): The intranasal mupirocin calcium formulation is appropriate and effective against gram-positive cocci including S. aureus and Streptococcus species 4, 5
- For non-infectious causes (trauma, dryness, irritation): Mupirocin is not indicated and alternative wound care is needed 4
- For deep or extensive infections with systemic signs: Systemic antibiotics are required rather than topical therapy 4
Common Pitfall to Avoid
The most critical error is using the wrong formulation. Healthcare providers sometimes prescribe standard mupirocin 2% ointment for intranasal use because it is more commonly stocked, but this violates FDA labeling and exposes patients to unnecessary adverse effects from the polyethylene glycol vehicle 1. Always specify "mupirocin calcium ointment, intranasal" or "Bactroban Nasal" when prescribing for nasal use 1.