Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
BACITRACIN-NEOMYCIN-POLYMYXIN vs NEVANAC
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Bacitracin inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier that transports peptidoglycan precursors. Neomycin and polymyxin B are aminoglycoside and polypeptide antibiotics, respectively; neomycin binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibiting protein synthesis, while polymyxin B disrupts bacterial cell membrane integrity by interacting with lipopolysaccharides and phospholipids, leading to increased permeability and cell death.
Nepafenac is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, primarily COX-2, reducing prostaglandin synthesis and thereby suppressing ocular inflammation and pain.
Treatment of superficial bacterial infections of the skin and mucous membranes (e.g., wounds, burns, impetigo, folliculitis),Prophylaxis of minor skin abrasions and wounds to prevent infection,Off-label: Use in conjunctival irrigation or ophthalmic infections (as combination ophthalmic preparations)
Treatment of pain and inflammation associated with cataract surgery,Reduction of risk of macular edema following cataract surgery
Apply topically to affected area 2-5 times daily.
One drop of 0.1% ophthalmic suspension instilled into the affected eye(s) three times daily.
Bacitracin: 1.5 hours (prolonged in renal impairment); Neomycin: 2-3 hours (accumulates with renal dysfunction); Polymyxin B: 6-9 hours (increased in renal impairment).
The terminal elimination half-life of nepafenac is approximately 12.5 hours in plasma, while its active metabolite amfenac has a half-life of about 24 hours. This supports twice-daily dosing.
Not extensively metabolized. Systemic absorption from topical application is minimal; absorbed drug may undergo hepatic metabolism or be excreted renally unchanged.
Nepafenac is metabolized via ocular tissues to amfenac, the active metabolite. Systemic metabolism primarily involves hepatic conjugation and oxidation.
Bacitracin: primarily renal (>90% unchanged); Neomycin: renal (30-50% unchanged) with non-renal clearance; Polymyxin: renal excretion of parent drug (60-80% unchanged) with some biliary and fecal elimination.
Nepafenac is extensively metabolized, primarily via hydrolysis to amfenac. Renal excretion accounts for approximately 85% of the administered dose, with about 13% excreted as unchanged nepafenac and amfenac in urine. Fecal elimination is minimal.
Bacitracin: <10% bound to plasma proteins; Neomycin: 0-30% bound; Polymyxin B: 50-70% bound, primarily to alpha-1-acid glycoprotein and lipoproteins.
Nepafenac is approximately 98% bound to plasma proteins, primarily albumin.
Bacitracin: 0.3 L/kg (confined to extracellular fluid); Neomycin: 0.2-0.3 L/kg (low tissue penetration except renal cortex); Polymyxin B: 0.7-1.0 L/kg (extensive tissue binding).
The apparent volume of distribution (Vd/F) is approximately 0.6 L/kg (range 0.5-0.7 L/kg), suggesting distribution into total body water and some tissue binding.
Oral: negligible (<1%) for all three components; topical: minimal systemic absorption via intact skin (<0.5%); ophthalmic/otic: minimal absorption via mucosal surfaces.
Ophthalmic: Systemic bioavailability after topical ocular administration is very low (approximately 0.1-1% of the dose), but sufficient for local ocular effects. Oral bioavailability is not clinically relevant as drug is only used ophthalmically.
No systemic absorption; no dosage adjustment required.
No dose adjustment required in renal impairment; systemic exposure is minimal due to topical administration.
No systemic absorption; no dosage adjustment required.
No dose adjustment required in hepatic impairment; systemic exposure is minimal.
Apply topically to affected area 2-5 times daily; same as adult dose.
Safety and efficacy in pediatric patients have not been established; use is not recommended.
Apply topically to affected area 2-5 times daily; same as adult dose.
No specific dose adjustment; dosing is identical to standard adult dosing.
Not applicable for topical formulations. However, systemic use of bacitracin (rare) may cause nephrotoxicity and anaphylactic reactions. Neomycin may cause ototoxicity and nephrotoxicity with systemic absorption.
No FDA black box warning.
Prolonged use may result in overgrowth of nonsusceptible organisms including fungi.,Topical use may cause allergic contact dermatitis, especially with neomycin.,Avoid application to large areas, open wounds, or damaged skin due to potential systemic absorption and toxicity.,Use with caution in patients with renal impairment or pre-existing hearing loss (neomycin component).,Ototoxicity and nephrotoxicity may occur if significant systemic absorption occurs.
Increased bleeding time due to antiplatelet effect,Delayed healing or corneal adverse events including keratitis and corneal perforation,Cross-sensitivity with aspirin or other NSAIDs,Use with caution in patients with bleeding diatheses or concurrent anticoagulants
Hypersensitivity to any component (bacitracin, neomycin, polymyxin B) or other aminoglycosides/polypeptide antibiotics.,Ophthalmic use in eyes with corneal abrasions or perforation (relative).,Known history of neomycin-associated ototoxicity or nephrotoxicity.
Hypersensitivity to nepafenac or any component of the formulation,History of asthma, urticaria, or allergic-type reactions to aspirin or other NSAIDs
No significant food interactions; topical application minimizes systemic absorption. No dietary restrictions.
No clinically significant food interactions have been identified with ophthalmic nevanac. Systemic absorption is minimal, so dietary restrictions are not required.
Bacitracin-Neomycin-Polymyxin is a topical combination with negligible systemic absorption; thus, fetal risk is minimal. No known teratogenic effects reported; animal studies for individual components show no fetal harm at systemic doses. However, neomycin has theoretical risk of ototoxicity if systemically absorbed, but topical use is considered low risk. FDA Pregnancy Category C for components, but topical use deemed safe.
Nepafenac is an NSAID. First trimester: limited human data, but NSAIDs as a class are associated with increased risk of spontaneous abortion and cardiac defects. Second trimester: generally considered lower risk for teratogenicity, but avoid if possible. Third trimester: increased risk of premature closure of the ductus arteriosus, oligohydramnios, and fetal renal impairment. Ophthalmic use results in minimal systemic absorption, but theoretical risks remain. Use only if clearly needed.
Minimal systemic absorption after topical application; excretion into breast milk is unlikely. M/P ratio not determined; safe for use during breastfeeding if applied to small areas and not to open wounds.
No data on nepafenac in breast milk. Ophthalmic administration yields negligible systemic concentrations. M/P ratio not determined. Considered likely compatible with breastfeeding due to minimal absorption, but caution advised.
No dosing adjustments necessary for pregnancy. Pharmacokinetic changes due to pregnancy (e.g., increased skin blood flow, hydration) are not clinically significant for this topical combination. Standard topical application is appropriate.
No dose adjustments are typically required due to ophthalmic administration; systemic exposure is negligible. However, avoid use in third trimester unless potential benefit outweighs risk. No pharmacokinetic changes in pregnancy necessitate dose adjustment for topical ophthalmic formulation.
Triple antibiotic ointment (bactiracin-neomycin-polymyxin) is first-line for prophylaxis of minor skin infections; avoid use on large areas, deep wounds, or burns due to risk of systemic absorption and nephrotoxicity. Neomycin carries high risk of allergic contact dermatitis; consider alternative in patients with known hypersensitivity. Topical use only; not for ophthalmic or intranasal application due to polymyxin ocular toxicity. Synergistic coverage includes Gram-positive (bacitracin), Gram-negative (polymyxin), and broad-spectrum (neomycin).
Nevanac (nepafenac) is a nonsteroidal anti-inflammatory drug (NSAID) ophthalmic suspension indicated for pain and inflammation associated with cataract surgery. Its prodrug formulation enhances corneal penetration, with active metabolite amfenac inhibiting COX-1 and COX-2. Administer one drop three times daily starting 1 day prior to surgery, continuing on day of surgery and for 2 weeks postoperatively. Avoid concurrent use of other NSAIDs or corticosteroids to mitigate risk of corneal adverse events. Monitor for signs of corneal epithelial breakdown, especially in patients with compromised corneal innervation (e.g., diabetes, prior ocular surgery).
Apply a thin layer to clean, minor cuts, scrapes, or burns 1-3 times daily.,Do not use on large body areas, deep puncture wounds, animal bites, or serious burns.,Stop use and consult doctor if rash, irritation, or signs of infection (worsening redness, swelling, pus) develop.,Avoid use on eyes, nose, or mouth; if contact occurs, rinse thoroughly with water.,Tell your doctor if you have kidney problems or are allergic to any of the ingredients (bacitracin, neomycin, polymyxin B).
Wash hands before and after instilling the drop.,Remove contact lenses before use and wait 10 minutes after administering before reinserting.,Do not touch the dropper tip to any surface to avoid contamination.,Apply one drop to the affected eye three times daily as directed, starting one day before cataract surgery.,Temporary blurred vision may occur; avoid driving or operating machinery until vision clears.,Notify your doctor if you experience eye pain, redness, sensitivity to light, or changes in vision.,Do not use other eye drops without consulting your doctor, especially other anti-inflammatory medications.,Store the bottle upright at room temperature, away from heat and light, and discard any unused suspension after the treatment period.
"The therapeutic efficacy of Picosulfuric acid can be decreased when used in combination with Bacitracin."
"Bacitracin may increase the nephrotoxic activities of Colistimethate."
"Bacitracin may increase the nephrotoxic activities of Streptomycin."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about BACITRACIN-NEOMYCIN-POLYMYXIN vs NEVANAC, answered by our medical review team.
BACITRACIN-NEOMYCIN-POLYMYXIN is a Aminoglycoside Antibiotic that works by Bacitracin inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier that transports peptidoglycan precursors. Neomycin and polymyxin B are aminoglycoside and polypeptide antibiotics, respectively; neomycin binds to the 30S ribosomal subunit, causing misreading of m RNA and inhibiting protein synthesis, while polymyxin B disrupts bacterial cell membrane integrity by interacting with lipopolysaccharides and phospholipids, leading to increased permeability and cell death.. NEVANAC is a NSAID Ophthalmic that works by Nepafenac is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, primarily COX-2, reducing prostaglandin synthesis and thereby suppressing ocular inflammation and pain.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between BACITRACIN-NEOMYCIN-POLYMYXIN and NEVANAC depend on the specific clinical indication. These are agents from distinct pharmacological classes and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of BACITRACIN-NEOMYCIN-POLYMYXIN is: Apply topically to affected area 2-5 times daily.. The standard adult dose of NEVANAC is: One drop of 0.1% ophthalmic suspension instilled into the affected eye(s) three times daily.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between BACITRACIN-NEOMYCIN-POLYMYXIN and NEVANAC in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. BACITRACIN-NEOMYCIN-POLYMYXIN is classified as Category A/B. Bacitracin-Neomycin-Polymyxin is a topical combination with negligible systemic absorption; thus, fetal risk is minimal. No known teratogenic effects reported; animal studies for i. NEVANAC is classified as Category C. Nepafenac is an NSAID. First trimester: limited human data, but NSAIDs as a class are associated with increased risk of spontaneous abortion and cardiac defects. Second trimester: . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.