MUPIROCIN
Clinical safety rating: safe
Animal studies have demonstrated safety
Mupirocin reversibly binds to bacterial isoleucyl-tRNA synthetase, inhibiting protein synthesis.
| Metabolism | Mupirocin is rapidly metabolized to monic acid, its inactive metabolite, following systemic absorption. |
| Excretion | Renal: <1% unchanged (topical); hepatic metabolism to monic acid, eliminated renally and fecally. After IV administration, 60-70% renal, 20-30% fecal/biliary. |
| Half-life | Intravenous: ~30 min (0.5 h). Topical: systemically absorbed amount negligible, local half-life not defined. |
| Protein binding | 95-97% bound to serum albumin. |
| Volume of Distribution | IV: 0.2-0.3 L/kg (small, limited to extracellular fluid; not distributed into CNS). |
| Bioavailability | Topical: minimal systemic absorption (<0.24% of dose); oral: negligible; IV: 100%. |
| Onset of Action | Topical: within 24-48 hours for bacterial inhibition; clinical improvement typically 3 days. |
| Duration of Action | Topical: bacteriostatic for up to 8 hours at site; clinical course treated for 5-14 days depending on indication. |
| Molecular Weight | 500.6 |
Apply a small amount of 2% ointment or cream to affected area three times daily for 5 to 14 days.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for topical use; oral absorption negligible. For intravenous use, mupirocin not available systemically. |
| Liver impairment | No dosage adjustment required for topical use; mupirocin is not hepatically metabolized. |
| Pediatric use | Age 2 months and older: Apply small amount of 2% ointment or cream to affected area three times daily for 5 to 14 days. For intranasal use: Apply half of a single-use tube (approximately 0.5 g) into each nostril twice daily for 5 days. |
| Geriatric use | No specific adjustments; use same dosing as adults. Monitor for skin irritation due to age-related skin changes. |
| 1st trimester | No known risks; limited data. Systemic absorption is minimal after topical application. Use only if clearly needed. |
| 2nd trimester | No known risks; limited data. Systemic absorption is minimal after topical application. Use only if clearly needed. |
| 3rd trimester | No known risks; limited data. Systemic absorption is minimal after topical application. Use only if clearly needed. |
Clinical note
No significant drug interactions For topical use only not for ophthalmic use.
| Placental transfer | No formal studies; due to minimal systemic absorption (<1% after topical application), placental transfer is expected to be negligible. |
| Breastfeeding | Systemic absorption after topical application is minimal. Mupirocin is unlikely to be present in breast milk in clinically significant amounts. Use with caution, especially on or near the breast, and avoid application to areas that may come into direct contact with the infant. |
■ FDA Black Box Warning
None.
| Common Effects | Itching Burning sensation Stinging sensation Pain |
| Serious Effects |
Hypersensitivity to mupirocin or any component of the formulation
| Precautions | Prolonged use may result in overgrowth of non-susceptible organisms including fungi., Not for intranasal use in infants less than 1 month of age (calcium mupirocin formulation)., For topical use only; avoid contact with eyes., Severe allergic reactions including anaphylaxis have been reported. |
| Food/Dietary | No significant food interactions. |
Loading safety data…
| Lactation Rating | L1 (Safe) |
| Teratogenic Risk | Animal studies have not shown evidence of fetal harm at topical doses. No well-controlled human studies. Systemic absorption is minimal. Use during pregnancy only if clearly needed. |
| Fetal Monitoring | No specific monitoring required for topical use. For systemic toxicity (rare), monitor renal function if extensive application. |
| Fertility Effects | No known effects on fertility in animal studies. |
| Clinical Pearls | Mupirocin is a topical antibiotic with activity against Staphylococcus aureus and Streptococcus pyogenes, including MRSA. It should not be used for longer than 10 days to minimize resistance. Intranasal application for MRSA decolonization requires specialized formulations. In impetigo, apply a small amount to lesions three times daily. |
| Patient Advice | Apply a thin layer to the affected area, typically 3 times daily. · Do not use on large areas of skin or open wounds unless directed by a physician. · Do not use longer than 10 days. · Avoid contact with eyes. · Wash hands before and after application. · Notify doctor if rash, itching, or irritation occurs. |