Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
BACITRACIN ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE vs ACUVAIL
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Bacitracin zinc inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier that transports peptidoglycan precursors. Neomycin sulfate and polymyxin B sulfate are aminoglycoside and polypeptide antibiotics, respectively; neomycin binds to 30S ribosomal subunit and causes misreading of m RNA, while polymyxin B disrupts bacterial cell membrane permeability by interacting with phospholipids.
Ketorolac tromethamine, a nonsteroidal anti-inflammatory drug (NSAID), inhibits prostaglandin synthesis by blocking cyclooxygenase (COX-1 and COX-2) enzymes. This reduces ocular inflammation and pain.
Topical treatment of bacterial infections of the skin and eye (e.g., conjunctivitis, keratitis, blepharitis),Prophylaxis of minor wounds, cuts, and abrasions
Reduction of ocular pain and inflammation following cataract surgery,Treatment of ocular itching associated with seasonal allergic conjunctivitis
Apply topically (ointment or cream) to affected area 1-3 times daily. For ophthalmic use, instill 1-2 drops into affected eye(s) every 3-4 hours.
1 drop in the affected eye 4 times daily.
Neomycin: 2-3 h; polymyxin B: 4.5-6 h; bacitracin: 1.5 h. Combined: effectively ~2-6 h depending on renal function; clinical context: prolonged with renal impairment.
Terminal elimination half-life is approximately 46 minutes in the aqueous humor following ocular administration in humans.
Not systemically absorbed after topical administration; no significant metabolism.
Primarily hepatic via conjugation with glucuronic acid; minor role of cytochrome P450 enzymes. Approximately 50% is excreted as parent drug and metabolites in urine.
Neomycin: ~99% renal; polymyxin B: ~60% renal, 40% fecal; bacitracin: mainly renal (over 90%). Combined: renal (predominant), with minor biliary/fecal contribution (polymyxin B).
Primarily renal excretion of metabolites; less than 1% excreted unchanged. Biliary/fecal elimination accounts for <10%.
Neomycin: 0-20%; polymyxin B: 60-80% (alpha-1-acid glycoprotein, albumin); bacitracin: <5%. Combined: ~40-50% bound overall.
>99% bound to plasma proteins, primarily albumin.
Neomycin: ~0.25 L/kg; polymyxin B: ~0.5 L/kg; bacitracin: ~0.3 L/kg. Combined Vd ~0.3-0.5 L/kg, reflecting limited distribution mainly to extracellular fluid.
Intravenous administration in animals suggests Vd ~0.15 L/kg, indicating limited distribution; clinically, it distributes into aqueous humor after topical dosing.
Topical/ophthalmic/otic: negligible systemic absorption (<0.1%).
Ocular bioavailability is dependent on formulation; systemic bioavailability after topical ocular administration is extremely low (<1%).
No systemic absorption with typical topical use; no adjustment necessary. For extensive use on damaged skin, monitor renal function and adjust if needed; no specific GFR-based guidelines.
No adjustment required. Drug is minimally systemically absorbed.
No adjustment needed for topical use. No systemic effects expected.
No adjustment required. Drug is minimally systemically absorbed.
Same as adult dosing for topical use. For neonates, use with caution on large surface areas; avoid prolonged use.
Safety and efficacy in pediatric patients have not been established.
No specific age-related adjustments. Use with caution on fragile skin; apply sparingly to avoid systemic absorption.
No specific dosage adjustment is recommended; use same dose as younger adults.
None.
No black box warning for ophthalmic use; however, systemic NSAIDs carry risk of serious cardiovascular and gastrointestinal events. Ophthalmic use rarely associated with corneal adverse events.
Prolonged use may result in overgrowth of nonsusceptible organisms including fungi.,Neomycin is ototoxic and nephrotoxic if absorbed systemically (e.g., applied to large areas of damaged skin).,Avoid contact with eyes other than for ophthalmic use.,Cross-allergenicity among aminoglycosides exists.
Use with caution in patients with bleeding disorders or those on anticoagulants; may prolong bleeding time. Avoid in patients with known hypersensitivities to NSAIDs or aspirin. Can cause corneal keratopathy; discontinue if corneal epithelial breakdown occurs.
Hypersensitivity to any component of the product.,Otic use if tympanic membrane is perforated (risk of ototoxicity).
Hypersensitivity to any component of the formulation. Active corneal epithelial defect. Patients with aspirin-sensitive asthma.
No known food interactions with topical application.
No specific food interactions; systemic absorption is minimal with ophthalmic use. Avoid concurrent use of other NSAID eye drops due to additive irritation.
No evidence of teratogenicity in first trimester; animal studies show no fetal harm. Second and third trimester risk is low due to minimal systemic absorption from topical use. No known association with congenital anomalies.
Acuvail (ketorolac tromethamine ophthalmic solution) is classified as FDA Pregnancy Category C. Systemic exposure after ocular administration is minimal; however, NSAIDs may cause premature closure of the ductus arteriosus and oligohydramnios in the third trimester. Use during the first and second trimesters should be limited to cases where potential benefit outweighs risk; avoid during the third trimester due to risk of fetal harm.
Minimal systemic absorption suggests negligible excretion into breast milk; M/P ratio not determined. Considered compatible with breastfeeding by AAP; avoid application to breast area to prevent infant ingestion.
Ketorolac is excreted in human milk following systemic administration, but ocular doses produce negligible systemic levels. The M/P ratio is not determined for ophthalmic use. Use with caution in nursing mothers, as the clinical significance is likely low due to minimal systemic absorption.
No dosage adjustment required for topical use; systemic absorption is negligible. Use standard dosing as per non-pregnant adults.
No dosage adjustment is required for ophthalmic use during pregnancy, as systemic exposure is negligible. However, avoid use in third trimester due to risks. Pharmacokinetic changes in pregnancy do not significantly alter ocular delivery.
OTC triple antibiotic ointment; avoid use on deep wounds, puncture wounds, or animal bites due to risk of toxicity and lack of efficacy. Neomycin carries the highest risk of allergic contact dermatitis among topical antibiotics; consider patch testing if prolonged use needed. Polymyxin B can cause neurotoxicity and nephrotoxicity if applied to large wounds or damaged skin. Not for use in eyes, ears, or mucous membranes. Do not exceed 7 days of continuous use.
Acuvail (ketorolac tromethamine ophthalmic solution 0.45%) is a nonsteroidal anti-inflammatory drug (NSAID) for ocular use. It is preserved with sodium chloride and not benzalkonium chloride, reducing corneal epithelial toxicity. Administer 1 drop twice daily for ocular pain and inflammation following cataract surgery. Use caution in patients with bleeding tendencies or those on anticoagulants due to risk of increased ocular bleeding. Monitor for corneal epithelial defects and keratitis, especially with prolonged use.
Clean the affected area before applying a thin layer of ointment 1-3 times daily.,Do not use on large areas of skin, deep cuts, puncture wounds, or animal bites unless directed by a doctor.,Do not apply to eyes, nose, mouth, or inside ears.,Stop use and consult a doctor if rash or allergic reaction develops, condition worsens, or persists for more than 7 days.,Keep out of reach of children; seek medical attention if accidentally ingested.
Wash hands before each use; do not touch tip of bottle to eye or any surface to avoid contamination.,Remove contact lenses before instillation and wait at least 15 minutes before reinserting.,Contact your doctor if you experience eye pain, redness, vision changes, or if symptoms worsen.,Do not use this medication while wearing contact lenses unless directed by your doctor.,Store at room temperature, keep bottle tightly closed when not in use, and discard within 28 days of opening.
"Cisatracurium, a non-depolarizing neuromuscular blocking agent (NMBA), competitively blocks nicotinic acetylcholine receptors at the neuromuscular junction, causing skeletal muscle paralysis. Polymyxin B, a polypeptide antibiotic, can potentiate this neuromuscular blockade by reducing presynaptic acetylcholine release and stabilizing postsynaptic membranes, leading to prolonged and enhanced neuromuscular blockade. This interaction increases the risk of prolonged muscle paralysis, respiratory depression, and apnea, especially in patients with renal impairment or those receiving other NMBAs."
"Mecamylamine, a ganglionic blocking agent, potentiates the neuromuscular blocking effects of Polymyxin B, a polypeptide antibiotic. This interaction occurs through additive or synergistic inhibition of neuromuscular transmission, potentially leading to prolonged or intensified muscle relaxation, respiratory depression, and apnea. The clinical outcome may include enhanced toxicity, especially in patients with renal impairment or those receiving concurrent anesthetics or other neuromuscular blocking agents."
"Decamethonium, a depolarizing neuromuscular blocker, enhances the neuromuscular blocking effects of Polymyxin B, a polypeptide antibiotic that can also cause neuromuscular blockade via direct membrane stabilization and calcium channel inhibition. This additive pharmacodynamic interaction can lead to prolonged or enhanced muscle weakness, potentially resulting in respiratory paralysis and apnea. Clinically, this combination increases the risk of acute respiratory failure and may prolong recovery from neuromuscular blockade."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about BACITRACIN ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE vs ACUVAIL, answered by our medical review team.
BACITRACIN ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE is a Aminoglycoside Antibiotic that works by Bacitracin zinc inhibits bacterial cell wall synthesis by interfering with dephosphorylation of the lipid carrier that transports peptidoglycan precursors. Neomycin sulfate and polymyxin B sulfate are aminoglycoside and polypeptide antibiotics, respectively; neomycin binds to 30S ribosomal subunit and causes misreading of m RNA, while polymyxin B disrupts bacterial cell membrane permeability by interacting with phospholipids.. ACUVAIL is a NSAID Ophthalmic that works by Ketorolac tromethamine, a nonsteroidal anti-inflammatory drug (NSAID), inhibits prostaglandin synthesis by blocking cyclooxygenase (COX-1 and COX-2) enzymes. This reduces ocular inflammation and pain.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between BACITRACIN ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE and ACUVAIL 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 ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE is: Apply topically (ointment or cream) to affected area 1-3 times daily. For ophthalmic use, instill 1-2 drops into affected eye(s) every 3-4 hours.. The standard adult dose of ACUVAIL is: 1 drop in the affected eye 4 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 ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE and ACUVAIL 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 ZINC-NEOMYCIN SULFATE-POLYMYXIN B SULFATE is classified as Category A/B. No evidence of teratogenicity in first trimester; animal studies show no fetal harm. Second and third trimester risk is low due to minimal systemic absorption from topical use. No . ACUVAIL is classified as Category C. Acuvail (ketorolac tromethamine ophthalmic solution) is classified as FDA Pregnancy Category C. Systemic exposure after ocular administration is minimal; however, NSAIDs may cause . Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.