Mupirocin

The 2% ointment treats impetigo caused by susceptible S. aureus or S. pyogenes. The 2% cream treats secondarily infected traumatic skin lesions caused by those susceptible organisms, limited to lesions up to 10 cm long or 100 cm² in area. Neither skin product is labeled for intranasal, ophthalmic, or other mucosal use.

IDSA supports topical therapy for selected impetigo, while numerous lesions, outbreaks, or ecthyma can require systemic therapy. For recurrent S. aureus infection, it describes a combined five-day intranasal mupirocin, chlorhexidine, and personal-item decontamination option with weak/low-quality support. That guidance does not authorize applying the selected skin products inside the nose; nasal product availability, exact formulation, age limits, and any off-label use require a separate clinician/pharmacist review.

Apply with a cotton swab or gauze pad; the area may be covered with gauze. Wash hands before and after use. These are the selected product-label regimens.

IDSA’s current-listed 2014 SSTI guideline recommends topical mupirocin twice daily for five days for selected bullous/nonbullous impetigo. This differs from the ointment label’s three-times-daily course; the prescriber should explicitly select and document the regimen. It is not a universal cream or decolonization schedule.

Avoid eyes, nose, mouth, vagina, and other mucosal surfaces. Do not layer with other lotions, creams, or ointments; concurrent application has not been studied. Do not extend treatment without reassessment because nonsusceptible organisms may overgrow.

Known hypersensitivity to mupirocin or any formulation excipient is a contraindication. Route restrictions and PEG-risk avoidance retain their label dosing/warning classification rather than becoming invented class-wide contraindications.

Neither selected human skin-product label contains a boxed warning. Hypersensitivity, irritation, diarrhea, overgrowth, and the ointment’s vehicle risks still require counseling.

Ointment commonly reports local burning, stinging, pain, or itching; cream trials report headache, rash, and nausea, with local reactions also possible. Severe systemic allergy is reported after marketing; its frequency is unknown. Accidental swallowing or excessive application needs product-specific medical or poison-center assessment; the labels supply no home overdose remedy.

Do not apply concurrently with other lotions, creams, or ointments, as their effect on mupirocin exposure has not been studied. Do not dilute or mix the preparation without verified product-specific instructions.

These skin-product labels do not establish a systemic drug-interaction dosing algorithm. Low intact-skin absorption does not justify extrapolating safety to extensive wounds, mucosal use, or another vehicle. Review other medicines and topical exposures with the treating clinician.

Human pregnancy data are insufficient to establish drug-associated risk; intact-skin systemic absorption is minimal, but that does not prove fetal safety. Milk transfer, infant effects, and milk-production effects are unknown. Weigh treatment need and breastfeeding benefits; wash a treated breast/nipple thoroughly before feeding to prevent direct oral exposure.

Ointment safety/effectiveness is established at age 2 months–16 years; cream at age 3 months–16 years. Younger infants are unestablished. Cream trials included a small older-adult subgroup without an overall difference in efficacy or safety; this does not establish every geriatric wound situation.

Neither selected skin label provides a renal/hepatic milligram adjustment schedule. The ointment’s PEG base is renally excreted after absorption: avoid situations allowing large PEG absorption, particularly in moderate/severe renal impairment. The cream has a different vehicle; do not assume that it has the same PEG warning or that it treats extensive wounds.

Mupirocin reversibly binds bacterial isoleucyl-tRNA synthetase, inhibiting protein synthesis, and is bactericidal at topical concentrations. Altered or acquired synthetases can confer resistance; the label notes more frequent resistance among MRSA than susceptible staphylococci and recommends appropriate susceptibility testing before MRSA use. The distinct mechanism does not eliminate acquired resistance.

Absorption through intact skin is minimal. Cream studies on larger damaged lesions detected some absorption via urinary monic acid; those studies do not enlarge the labeled lesion-size indication. Absorbed mupirocin is rapidly converted to inactive monic acid, predominantly cleared by the kidneys. Pharmacokinetic IV-study data do not make either skin product an injectable medicine.

Review diagnosis, extent of lesions, response at 3–5 days, local allergy/irritation, diarrhea, and evidence of nonsusceptible infection. For ointment, assess wound extent and renal/PEG risk before use. There is no routine serum-concentration target or universal laboratory schedule in these topical labels.

Use only on the prescribed skin site and follow the selected course. Wash hands, use a swab/gauze, and keep away from eyes and mucosa. Do not share or mix with other topical products. Stop and seek help for severe irritation/rash or systemic allergy, and report significant diarrhea. Tell the clinician if breastfeeding or treating large/open wounds; wash treated breast/nipple skin before feeding.

The selected Sun-distributed human ointment is 20 mg/g in a PEG water-miscible base; its 22-g tube is NDC 51672-1312-0. The white Sun-distributed cream contains mupirocin calcium equivalent to 20 mg mupirocin/g in an oil/water emulsion; its 15-g tube is NDC 51672-1370-1. Verify the manufacturer/package rather than assuming every 2% product has the same vehicle.

Covered human skin products are ointment 2% (20 mg/g), with 15-, 22-, and 30-g tubes in the selected label, and cream 2% (20 mg/g), in 15- and 30-g tubes. Nasal-specific ointment, compounded/off-label decolonization preparations, and veterinary products are outside this product review.

Store both skin products at 20–25°C. Do not freeze the cream. Keep away from children, and retain the exact package directions; the labels do not provide a universal compounded preparation shelf life.