From the Guidelines
Bacitracin and mupirocin are both topical antibiotics used to treat skin infections, but mupirocin is generally preferred for more serious skin infections due to its greater potency and broader spectrum, including activity against methicillin-resistant Staphylococcus aureus (MRSA) 1.
Key Differences
- Bacitracin is a polypeptide antibiotic that works by inhibiting bacterial cell wall synthesis and is effective primarily against gram-positive bacteria.
- Mupirocin, on the other hand, is a stronger prescription-only antibiotic that inhibits bacterial protein synthesis by binding to bacterial isoleucyl-tRNA synthetase.
- Mupirocin has broader activity against both gram-positive and some gram-negative bacteria, including MRSA.
Clinical Use
- Bacitracin is commonly available over-the-counter in ointment form and is often used for minor cuts, scrapes, and burns.
- Mupirocin is particularly effective for treating impetigo, folliculitis, and eradicating nasal MRSA colonization.
- For nasal decolonization, mupirocin 2% is typically applied to each nostril twice daily for 5-10 days.
Important Considerations
- Bacitracin has a narrower spectrum of activity and is more likely to cause allergic reactions in some patients.
- To prevent antibiotic resistance, neither bacitracin nor mupirocin should be used for prolonged periods or for routine wound care when infection is not present.
- The choice between bacitracin and mupirocin should be based on the severity of the infection and the suspected causative organisms, with mupirocin being preferred for more serious infections or those caused by MRSA 1.
From the Research
Comparison of Bacitracin and Mupirocin
- Bacitracin and mupirocin are two topical antibiotics used to treat skin infections, but they have different mechanisms of action and spectra of activity 2.
- Mupirocin is a unique antimicrobial agent that inhibits bacterial protein and RNA synthesis by reversibly inhibiting isoleucyl-transfer RNA, whereas bacitracin has a narrower antibacterial spectrum 3, 2.
- Mupirocin has excellent in vitro activity against staphylococci and most streptococci, but less activity against other gram-positive and gram-negative bacteria 3.
- Bacitracin, on the other hand, may produce treatment failure and sensitization when used topically 2, 4.
- Clinical trials have shown that mupirocin is effective in treating impetigo and wound infections caused by gram-positive pathogens, including Staphylococcus aureus 3, 5.
Spectrum of Activity
- Mupirocin has a broader spectrum of activity than bacitracin, including activity against staphylococci and streptococci 3, 2.
- Bacitracin has a narrower spectrum of activity, primarily against gram-positive bacteria 2.
- Mupirocin is also effective against some gram-negative bacteria, although its activity against these organisms is less well characterized 3, 5.
Clinical Uses
- Mupirocin is commonly used to treat impetigo, wound infections, and other superficial skin infections caused by gram-positive pathogens 3, 5.
- Bacitracin may be used to treat minor skin infections, but its use is limited due to the risk of treatment failure and sensitization 2, 4.
- Both antibiotics shouldn been used judiciously to minimize the risk of resistance and adverse effects 4.