BACIGUENT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BACIGUENT (BACIGUENT).
Bacitracin inhibits bacterial cell wall synthesis by dephosphorylating the lipid carrier that transports peptidoglycan precursors across the cell membrane, leading to accumulation of toxic intermediates and cell lysis.
| Metabolism | Bacitracin undergoes minimal systemic absorption via topical application; not significantly metabolized; excreted unchanged in urine if absorbed. |
| Excretion | Primarily renal excretion of unchanged drug via glomerular filtration and tubular secretion; >90% of absorbed dose recovered in urine within 24 hours; biliary/fecal elimination minimal (<2%) |
| Half-life | Terminal elimination half-life approximately 2.5–3.5 hours in adults with normal renal function; prolonged in renal impairment (up to 20–30 hours in anuria) |
| Protein binding | Approximately 20–30% bound to serum proteins, mainly albumin |
| Volume of Distribution | 0.25–0.4 L/kg (total body water); limited tissue distribution, primarily extracellular fluid |
| Bioavailability | Topical: negligible systemic absorption (<0.5%) through intact skin; oral: not absorbed (inactivated in GI tract; not used systemically) |
| Onset of Action | Topical: detectable antimicrobial effect within 1–2 hours after application; systemic absorption negligible via intact skin |
| Duration of Action | Bactericidal activity persists 6–12 hours after topical application; systemic levels (if absorbed) decline rapidly due to short half-life |
| Molecular Weight | 1422.69 |
Topical: Apply thin layer to affected area 1 to 3 times daily; maximum duration of therapy is 1 week.
| Dosage form | OINTMENT |
| Renal impairment | No dose adjustment required for topical use; systemic absorption is minimal. |
| Liver impairment | No dose adjustment required for topical use. |
| Pediatric use | Apply thin layer to affected area 1 to 3 times daily; safety in infants under 2 months not established. |
| Geriatric use | No specific dose adjustment; use same as adult dosing. |
| 1st trimester | Topical bacitracin is not absorbed systemically in significant amounts, but avoid use over large areas or on broken skin during first trimester due to theoretical risk of nephrotoxicity; minimal systemic absorption limits fetal exposure. |
| 2nd trimester | Topical bacitracin is generally considered safe in second trimester when used on small areas; avoid extensive application or use on denuded skin. |
| 3rd trimester | Topical bacitracin is considered safe in third trimester for small-area use; no known fetal harm, but avoid prolonged use on large wounds. |
Clinical note
Comprehensive clinical and safety monograph for BACIGUENT (BACIGUENT).
| Placental transfer | Topical bacitracin has negligible systemic absorption, so placental transfer is likely minimal. No documented adverse fetal effects from topical use. |
| Breastfeeding | Topical bacitracin is not absorbed systemically in significant amounts, so minimal transfer into breast milk is expected. It is considered compatible with breastfeeding when applied to small areas. Avoid application to the breast or nipple area to prevent infant ingestion. |
■ FDA Black Box Warning
Due to nephrotoxicity, bacitracin is NOT recommended for parenteral use; topical use only.
| Serious Effects |
Hypersensitivity to bacitracin or any component of the formulationKnown previous allergic reaction to bacitracin
| Precautions | Hypersensitivity reactions including anaphylaxis, Prolonged use may result in overgrowth of non-susceptible organisms, including fungi, Avoid contact with eyes, Not for use on deep wounds or severe burns |
| Food/Dietary | No known food interactions with topical bacitracin. Avoid ingestion. |
| Clinical Pearls |
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| Lactation Rating | L1 (Safe) |
| Teratogenic Risk | Bacitracin is not systemically absorbed from topical application, so fetal exposure is negligible. No known teratogenic risk in any trimester; however, systemic use (IM) is contraindicated due to nephrotoxicity, and limited data exist for systemic use in pregnancy. Animal studies show no evidence of harm, but human data are insufficient. |
| Fetal Monitoring | No specific monitoring required for topical use. For systemic use (IM), monitor renal function (serum creatinine, BUN, urine output) due to nephrotoxicity risk. Fetal monitoring not indicated for topical application. |
| Fertility Effects | No known effects on fertility. Systemic absorption is minimal with topical use. No data suggest impairment of male or female fertility. |
| Bacitracin is a topical polypeptide antibiotic effective against gram-positive organisms. It is often combined with neomycin and polymyxin B in triple antibiotic ointments. For minor wounds, apply a thin layer 1-3 times daily. Avoid use on large body surface areas or for deep puncture wounds due to risk of systemic absorption and nephrotoxicity. Monitor for allergic contact dermatitis, especially with prolonged use. |
| Patient Advice | Clean the affected area before each application. · Apply a thin layer of ointment 1 to 3 times daily. · Do not use on large areas of the body, deep wounds, or animal bites. · Stop use and consult a doctor if the condition worsens or does not improve within 1 week. · Avoid contact with eyes or mucous membranes. |