The chemistry, mechanism of action, antimicrobial activity, pharmacokinetics, clinical efficacy, adverse effects, dosage, and administration of
mupirocin are reviewed.
Mupirocin, formerly termed
pseudomonic acid A, is a topical
antibiotic under investigation for the treatment of
impetigo and other superficial primary and secondary skin
infections.
Mupirocin (
Bactroban, Beecham Laboratories) is currently formulated
as a 2%
ointment in a water-miscible
polyethylene glycol base. The
drug is a unique
antimicrobial agent because of its structure and mechanism of action.
Mupirocin apparently exerts its antimicrobial activity by reversibly inhibiting isoleucyl-
transfer RNA, thereby inhibiting
bacterial protein and
RNA synthesis.
Mupirocin has excellent in vitro activity against staphylococci and most streptococci but less activity against other gram-positive and gram-negative bacteria. The
drug will only be used topically because of its rapid and extensive systemic metabolism. Several controlled clinical trials documented that
mupirocin was significantly better than the
polyethylene glycol vehicle alone or
ampicillin and as effective as
cloxacillin,
dicloxacillin, or
erythromycin in producing clinical and bacteriological cures in patients with
impetigo and
wound infections caused by gram-positive pathogens. Limited studies suggest that
mupirocin may also have a role in eradicating nasal carriage of staphylococci. Reported adverse effects are local and may be related to the
polyethylene glycol vehicle base.
Mupirocin should be useful for treating patients with
impetigo and
wound infections caused by Staphylococcus aureus. However, additional controlled, comparative clinical studies are needed to identify the role of
mupirocin in treating other primary and secondary skin
infections and for eliminating nasal carriage of staphylococci.