What is Mupirocin?
Mupirocin is a topical antibiotic derived from
Pseudomonas fluorescens. It is primarily used in the treatment of skin infections, particularly those caused by
Staphylococcus aureus and
Streptococcus pyogenes. Mupirocin works by inhibiting bacterial protein synthesis, specifically by targeting the bacterial isoleucyl-tRNA synthetase, which is essential for the production of proteins.
What are the Clinical Uses of Mupirocin?
Mupirocin is commonly used to treat various
superficial skin infections such as impetigo, folliculitis, and furunculosis. It is also used for the topical decolonization of nasal carriers of methicillin-resistant Staphylococcus aureus (
MRSA). In hospital settings, mupirocin is often applied intranasally to reduce the risk of MRSA infection in patients undergoing surgery or those in intensive care units.
How is Mupirocin Administered?
Mupirocin is available in several formulations, including ointment and cream for dermatological use, and as a nasal ointment for decolonization purposes. For treating skin infections, it is typically applied directly to the affected area three times a day. For nasal decolonization, a small amount is applied inside each nostril, usually twice a day for five days.
What are the Side Effects of Mupirocin?
Mupirocin is generally well-tolerated with minimal side effects. The most common adverse reactions include localized skin irritation, itching, or a burning sensation at the site of application. Rarely, systemic allergic reactions can occur. Long-term use is not recommended due to the risk of developing
bacterial resistance or secondary fungal infections.
What is the Resistance Profile of Mupirocin?
Resistance to mupirocin can develop, particularly with prolonged use or misuse. Resistance can occur through mutations in the isoleucyl-tRNA synthetase or through the acquisition of the
mupA gene, which encodes an alternate isoleucyl-tRNA synthetase. Resistant strains are more frequently encountered in settings with widespread mupirocin use, such as hospitals. It is crucial to use mupirocin judiciously to prevent the development and spread of resistant bacteria.
When Should Mupirocin Not Be Used?
Mupirocin should not be used in individuals with known hypersensitivity to the drug or any of its components. It is also not suitable for treating extensive skin infections or infections that require systemic therapy. In such cases, oral or intravenous antibiotics may be necessary. Additionally, mupirocin is not recommended for use in the eyes or mucous membranes, except for its specific nasal application.
How Does Mupirocin Compare to Other Topical Antibiotics?
Compared to other topical antibiotics like
bacitracin and
neomycin, mupirocin has a unique mechanism of action and a more targeted spectrum of activity. It is particularly effective against Gram-positive bacteria, including MRSA, making it a valuable option for treating resistant infections. However, its use should be limited to avoid resistance, and it is often part of a
multimodal strategy in infection control.
