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Pharmacology: Pharmacokinetics: Only very small amounts of topically applied mupirocin are absorbed into the systemic circulation where it is rapidly metabolised to monic acid which is excreted in the urine.

Microbiology: Mupirocin is an antibacterial that inhibits bacterial protein synthesis by binding to isoleucyl transfer RNA synthetase. It is mainly bacteriostatic at low concentrations, although it is usually bactericidal in the high concentrations achieved by topical application to the skin. At these concentrations, it may have some activity against organisms reported to be relatively resistant to mupirocin in vitro. It is mainly active against Gram-positive aerobes. Most strains of staphylococci (including methicillin-resistant and multiply-resistant Staph. aureus) and streptococci are susceptible in vitro, although the enterococci are relatively resistant. Mupirocin is also active against Listeria monocytogenes and Erysipelothrix rhusiopatiae.

The Gram-negative organisms are generally insensitive, but Haemophilus influenzae, Neisseria spp. and a few others are sensitive. Anaerobic organisms, both Gram-positive and Gram-negative are generally resistant, and activity against fungi is low. Mupirocin is more active in vitro at acid pH than in alkaline conditions. Naturally resistant strains of Staph. aureus occur rarely but resistance, including high-level plasmid-mediated transferable resistance, has emerged, particularly during long term use. There has been some concern that inappropriate prescribing of mupirocin has led to this steadily increasing resistance.

Indications/Uses

Mupirocin is indicated for the topical treatment of primary and secondary bacterial skin infections caused by Staphylococcus aureus and other susceptible organisms.

Dosage/Direction for Use

Mupirocin is an antibacterial produced by Pseudomonas fluorescens. It is applied topically as a 2% ointment in a macrogol base, or as a cream containing mupirocin calcium equivalent to 2% mupirocin, in the treatment of various bacterial skin infections. These preparations should be applied up to 3 times daily for up to 10 days
treatment should be re-evaluated if there is no response after 3 to 5 days.

Contraindications

Hypersensitivity to Mupirocin or any of its constituents.

Special Precautions

Some mupirocin products are formulated in a macrogol base
such formulations are not suitable for application to mucous membranes and should be used with caution in patients with extensive burns or wounds because of the possibility of macrogol toxicity. Care is also required in patients with renal impairment.

Adverse Reactions

Mupirocin is usually well tolerated but local reactions such as burning, stinging, and itching may occur after the application of mupirocin to the skin.

View ADR Monitoring Form

Storage

Store at temperatures not exceeding 30