Can a pregnant patient use mupirocin (Bactroban) ointment?

Mupirocin Ointment Use in Pregnancy

Mupirocin ointment can be used during pregnancy when clearly needed, as it is classified as Pregnancy Category B with no evidence of fetal harm in animal studies, though adequate human data are lacking. 1

FDA Classification and Safety Data

• Mupirocin is designated as Pregnancy Category B, meaning reproduction studies in rats and rabbits at doses up to 22 and 43 times the human topical dose (approximately 60 mg/day) showed no evidence of harm to the fetus 1
• However, because animal studies are not always predictive of human response, the FDA label states this drug should be used during pregnancy only if clearly needed 1
• No systemic absorption of mupirocin or its major metabolite (monic acid) has been detected after topical administration in clinical studies, which supports its safety profile 2

Clinical Evidence in Pregnant Patients

• There is limited but reassuring real-world evidence: one case report documented successful use of mupirocin ointment (along with other treatments) in a pregnant woman at 13 weeks gestation with rosacea fulminans, with no reported adverse fetal outcomes 3
• The lack of systemic absorption is a key safety feature that distinguishes mupirocin from many other antibiotics that require more caution in pregnancy 2

Practical Recommendations

When mupirocin is indicated in pregnancy:

• Use for localized bacterial skin infections (impetigo, infected wounds, secondary skin infections) where the benefit of treating the infection outweighs theoretical risks 1, 4
• Apply 2-3 times daily to affected areas as in non-pregnant patients 5, 4
• Limit treatment duration to 3-5 days when possible, as prolonged use increases risk of resistance and is generally unnecessary 6
• Avoid use on large open wounds or damaged skin where polyethylene glycol absorption could theoretically occur, though renal impairment would need to be present for this to be clinically significant 1

Important Caveats

• Do not use the intranasal formulation (mupirocin calcium ointment) without specific indication, as the standard 2% ointment is not formulated for mucosal surfaces 1
• Mupirocin should not be used for ocular infections under any circumstances, including in pregnancy 7
• If skin infection shows signs of systemic involvement or fails to improve within 3-5 days, consider oral antibiotics with established pregnancy safety profiles 8

Breastfeeding Considerations

• It is unknown whether mupirocin is excreted in human milk, so caution is advised when administering to nursing mothers 1
• Given the lack of systemic absorption with topical use, the risk to breastfed infants is likely minimal, though this should be discussed with patients 1, 2