Which Mupirocin Formulation for Intranasal Use
Use mupirocin calcium nasal ointment 2% (Bactroban Nasal) for intranasal application—the standard mupirocin ointment formulation is NOT approved for intranasal use and should be avoided. 1
Critical Distinction Between Formulations
The FDA-approved mupirocin ointment (for skin infections like impetigo) explicitly states it is not formulated for intranasal use and warns that "intranasal use has been associated with isolated reports of stinging and drying." 1 The FDA label specifically directs clinicians: "A separate formulation, mupirocin nasal ointment, is available for intranasal use." 1
Standard Intranasal Dosing Protocol
Apply approximately 0.5 grams (about half the amount from a single-use tube) of mupirocin calcium 2% nasal ointment into each nostril twice daily for 5 days (total of 10 doses). 2, 3, 4
- This 10-dose regimen achieves 89.5% sustained decolonization for at least four weeks post-treatment, significantly superior to abbreviated 6-dose regimens (68.0% success rate, p=0.016). 5
- Local concentrations exceed inhibitory levels for staphylococci and remain detectable for up to 72 hours after application. 3
Clinical Context-Specific Applications
Preoperative Decolonization
Begin mupirocin nasal application at least 48 hours before surgery and continue for the full 5-7 day course to reduce postoperative Staphylococcus aureus infections by 45% (RR 0.55,95% CI 0.34-0.89). 6, 2
- Combine with daily chlorhexidine body washes and twice-daily chlorhexidine mouthwash for optimal results, reducing MRSA carriage by 37% (RR 0.63,95% CI 0.52-0.75). 6, 2
- Routine decolonization without prior screening is more cost-effective than selective treatment based on positive cultures. 2
MRSA Outbreak Control
Apply mupirocin nasal ointment twice daily for 5 days to healthcare workers and colonized patients as part of comprehensive infection control programs during institutional MRSA outbreaks. 3, 4
- Achieves >95% eradication of nasal MRSA carriage in controlled studies. 4
- Bacteriological monitoring shows 93% eradication rates for MRSA specifically. 7
Important Safety Considerations
Resistance Development
The CDC guidelines note that mupirocin resistance develops in both S. aureus and coagulase-negative staphylococci soon after routine use is instituted. 6 This concern must be balanced against the proven clinical benefits in high-risk situations like preoperative decolonization and outbreak control.
Common Adverse Effects
Mild to moderate nasal symptoms occur in a small percentage of patients, including burning, stinging, nasal erythema, swelling, pruritus, and dryness. 3, 8 Approximately 10% of subjects may experience these local reactions, though they rarely require discontinuation. 8
Recolonization Patterns
After successful decolonization, recolonization occurs in approximately 52% of individuals within 3-4 months—19% with the same strain and 33% with different staphylococcal strains. 7 For recurrent infections in immunocompetent patients, consider monthly 5-day courses of mupirocin, which reduces positive nasal cultures by 73% and skin infections by 58% over one year. 2