Version July 2025
Corneal abrasion (off-label use): Ophthalmic: Instill 1 drop in affected eye(s) 4 times daily for 3 to 5 days (Ref).
Ocular infections, mild to moderate (bacterial conjunctivitis, blepharoconjunctivitis): Ophthalmic: Instill 1 drop in affected eye(s) every 3 hours (maximum: 6 doses per day) for 7 to 10 days; has also been used 4 times daily for 5 to 7 days (Ref).
There are no dosage adjustments provided in the manufacturer's labeling.
There are no dosage adjustments provided in the manufacturer's labeling.
Refer to adult dosing.
(For additional information see "Trimethoprim and polymyxin B: Pediatric drug information")
Conjunctivitis, blepharoconjunctivitis: Infants ≥2 months, Children, and Adolescents: Ophthalmic: Instill 1 drop in eye(s) every 3 hours; maximum daily dose: 6 doses/day for 7 to 10 days; in children and adolescents, 4 times daily dosing for 5 to 7 days has also been used (Ref).
There are no dosage adjustments provided in manufacturer’s labeling.
There are no dosage adjustments provided in manufacturer’s labeling.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.
Frequency not defined:
Dermatologic: Circumocular rash
Ophthalmic: Burning sensation of eyes, eyelid edema, eye pruritus, eye redness (increased), lacrimation, stinging of eyes
Hypersensitivity to trimethoprim, polymyxin B, or any component of the formulation
Concerns related to adverse effects:
• Superinfection: Prolonged use may lead to overgrowth of nonsusceptible organisms, including fungi. If superinfection is suspected, institute appropriate alternative therapy.
Special populations:
• Pediatrics: Not indicated for prophylaxis or treatment of ophthalmia neonatorum.
Other warnings/precautions:
• Appropriate use: For topical ophthalmic use only. Do not introduce directly into anterior chamber of the eye. Inadvertent contamination of multiple-dose ophthalmic tube tip has caused bacterial keratitis. Contact lenses should not be worn during therapy.
Not indicated for prophylaxis or treatment of ophthalmia neonatorum.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution, ophthalmic: Trimethoprim 1 mg and polymyxin B sulfate 10,000 units per 1 mL (10 mL)
Polytrim: Trimethoprim 1 mg and polymyxin B sulfate 10,000 units per 1 mL (10 mL [DSC]) [contains benzalkonium chloride]
Yes
Solution (Polymyxin B-Trimethoprim Ophthalmic)
10000 unit/mL 0.1% (per mL): $1.18 - $1.74
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Ophthalmic: For ophthalmic use only; not for injection into the eye. Avoid contamination of the applicator tip with material from eye, fingers, or other sources. Avoid wearing contact lenses.
For topical use in eye only; not for injection. Avoid contamination of the applicator tip. Avoid wearing contact lenses. Apply finger pressure to lacrimal sac during and for 1 to 2 minutes after instillation to decrease risk of absorption and systemic effects.
Ocular infections, mild to moderate: Treatment of surface ocular bacterial infections, including conjunctivitis and blepharoconjunctivitis, caused by susceptible organisms.
Corneal abrasion
Refer to individual components.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Amantadine: Trimethoprim may increase adverse/toxic effects of Amantadine. Specifically, the risk of myoclonus or delirium may be increased. Trimethoprim may increase serum concentration of Amantadine. Risk C: Monitor
Aminoglycosides: Polymyxin B may increase nephrotoxic effects of Aminoglycosides. Polymyxin B may increase neurotoxic effects of Aminoglycosides. Risk X: Avoid
Amodiaquine: Trimethoprim may increase neutropenic effects of Amodiaquine. Trimethoprim may increase serum concentration of Amodiaquine. Management: Avoid coadministration of sulfamethoxazole/trimethoprim and amodiaquine in HIV-infected patients when possible due to the possible increased risk for neutropenia. If coadministration is required, monitor closely for neutropenia. Risk D: Consider Therapy Modification
Angiotensin II Receptor Blockers: Trimethoprim may increase hyperkalemic effects of Angiotensin II Receptor Blockers. Risk C: Monitor
Angiotensin-Converting Enzyme Inhibitors: Trimethoprim may increase hyperkalemic effects of Angiotensin-Converting Enzyme Inhibitors. Management: Consider avoiding coadministration if possible. If combined, monitor serum potassium closely, particularly for patients with other risk factors (eg, renal impairment, older age, and other medications that increase potassium. Risk X: Avoid
AzaTHIOprine: Trimethoprim may increase myelosuppressive effects of AzaTHIOprine. Risk C: Monitor
Bacillus clausii: Antibiotics may decrease therapeutic effects of Bacillus clausii. Management: Bacillus clausii should be taken in between antibiotic doses during concomitant therapy. Risk D: Consider Therapy Modification
Bacitracin (Systemic): Polymyxin B may increase nephrotoxic effects of Bacitracin (Systemic). Risk X: Avoid
BCG (Intravesical): Antibiotics may decrease therapeutic effects of BCG (Intravesical). Risk X: Avoid
BCG Vaccine (Immunization): Antibiotics may decrease therapeutic effects of BCG Vaccine (Immunization). Risk C: Monitor
Capreomycin: May increase neuromuscular-blocking effects of Polymyxin B. Risk C: Monitor
Cefazedone: May increase nephrotoxic effects of Polymyxin B. Risk C: Monitor
Cephaloridine: Polymyxin B may increase nephrotoxic effects of Cephaloridine. Risk C: Monitor
Cholera Vaccine: Antibiotics may decrease therapeutic effects of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid
Clofarabine: OCT2 Inhibitors may increase serum concentration of Clofarabine. Risk C: Monitor
Colistimethate: May increase nephrotoxic effects of Polymyxin B. Colistimethate may increase neurotoxic effects of Polymyxin B. Polymyxin B may increase neuromuscular-blocking effects of Colistimethate. Management: Coadministration of polymyxin B and other potentially neurotoxic or nephrotoxic agents, such as colistimethate, is generally not recommended. If this combination must be used, monitor carefully for enhanced neurotoxic and nephrotoxic effects. Risk D: Consider Therapy Modification
CycloSPORINE (Systemic): Trimethoprim may increase nephrotoxic effects of CycloSPORINE (Systemic). Trimethoprim may increase hyperkalemic effects of CycloSPORINE (Systemic). Risk C: Monitor
Dalfampridine: OCT2 Inhibitors may increase serum concentration of Dalfampridine. Management: Consider alternatives to this combination. Carefully weigh the risk of seizures against the benefit of combining OCT2 inhibitors with dalfampridine. Risk D: Consider Therapy Modification
Daprodustat: CYP2C8 Inhibitors (Weak) may increase serum concentration of Daprodustat. Risk C: Monitor
Dapsone (Systemic): Trimethoprim may increase serum concentration of Dapsone (Systemic). Dapsone (Systemic) may increase serum concentration of Trimethoprim. Risk C: Monitor
Digoxin: Trimethoprim may increase serum concentration of Digoxin. Risk C: Monitor
Dofetilide: Trimethoprim may increase serum concentration of Dofetilide. Risk X: Avoid
Fecal Microbiota (Live) (Oral): May decrease therapeutic effects of Antibiotics. Risk X: Avoid
Fecal Microbiota (Live) (Rectal): Antibiotics may decrease therapeutic effects of Fecal Microbiota (Live) (Rectal). Risk X: Avoid
Fosphenytoin-Phenytoin: Trimethoprim may increase serum concentration of Fosphenytoin-Phenytoin. Risk C: Monitor
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Antibiotics may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Kanamycin: Polymyxin B may increase adverse/toxic effects of Kanamycin. Management: Coadministration of kanamycin and other potentially ototoxic or nephrotoxic agents, such as polymyxin B, is not recommended. If this combination must be used, monitor carefully neurotoxic, ototoxic, or nephrotoxic effects. Risk D: Consider Therapy Modification
Lactobacillus and Estriol: Antibiotics may decrease therapeutic effects of Lactobacillus and Estriol. Risk C: Monitor
LamiVUDine: Trimethoprim may increase serum concentration of LamiVUDine. Risk C: Monitor
Leucovorin Calcium-Levoleucovorin: May decrease therapeutic effects of Trimethoprim. Management: Avoid concurrent use of leucovorin or levoleucovorin with trimethoprim (plus sulfamethoxazole) for Pneumocystis jirovecii pneumonia. If trimethoprim is used for another indication, monitor closely for reduced efficacy. Risk X: Avoid
Mecamylamine: Polymyxin B may increase neuromuscular-blocking effects of Mecamylamine. Risk X: Avoid
Memantine: Trimethoprim may increase adverse/toxic effects of Memantine. Specifically, the risk of myoclonus and/or delirium may be increased. Trimethoprim may increase serum concentration of Memantine. Risk C: Monitor
Mercaptopurine: Trimethoprim may increase myelosuppressive effects of Mercaptopurine. Risk C: Monitor
MetFORMIN: MATE1/2-K Inhibitors may increase serum concentration of MetFORMIN. Risk C: Monitor
Methotrexate: Trimethoprim may increase adverse/toxic effects of Methotrexate. Management: Consider avoiding concomitant use of methotrexate and either sulfamethoxazole or trimethoprim. If used concomitantly, monitor for the development of signs and symptoms of methotrexate toxicity (eg, bone marrow suppression). Risk D: Consider Therapy Modification
Methoxyflurane: May increase nephrotoxic effects of Polymyxin B. Risk X: Avoid
Mycophenolate: Antibiotics may decrease active metabolite exposure of Mycophenolate. Specifically, concentrations of mycophenolic acid (MPA) may be reduced. Risk C: Monitor
Netilmicin (Ophthalmic): Polymyxin B may increase nephrotoxic effects of Netilmicin (Ophthalmic). Risk X: Avoid
Neuromuscular-Blocking Agents: Polymyxin B may increase neuromuscular-blocking effects of Neuromuscular-Blocking Agents. Risk C: Monitor
Potassium-Sparing Diuretics: Trimethoprim may increase hyperkalemic effects of Potassium-Sparing Diuretics. Risk C: Monitor
PRALAtrexate: Trimethoprim may increase serum concentration of PRALAtrexate. More specifically, trimethoprim may decrease excretion of pralatrexate. Risk C: Monitor
Procainamide: Trimethoprim may increase serum concentration of Procainamide. Trimethoprim may increase active metabolite exposure of Procainamide. Management: Consider alternatives to trimethoprim-containing regimens to avoid this interaction. If coadministered, monitor for increased procainamide adverse effects (increased QTc) if trimethoprim is initiated/dose increased. Risk D: Consider Therapy Modification
Pyrimethamine: May increase adverse/toxic effects of Trimethoprim. Risk C: Monitor
Repaglinide: CYP2C8 Inhibitors (Weak) may increase serum concentration of Repaglinide. Risk C: Monitor
RifAMPin: May decrease serum concentration of Trimethoprim. Trimethoprim may increase serum concentration of RifAMPin. Risk C: Monitor
Sapropterin: Trimethoprim may decrease serum concentration of Sapropterin. Specifically, trimethoprim may decrease tissue concentrations of tetrahydrobiopterin. Risk C: Monitor
Sodium Picosulfate: Antibiotics may decrease therapeutic effects of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Risk D: Consider Therapy Modification
Typhoid Vaccine: Antibiotics may decrease therapeutic effects of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider Therapy Modification
Zidovudine: May increase neutropenic effects of Trimethoprim. Trimethoprim may increase serum concentration of Zidovudine. Risk C: Monitor
Adverse events have been observed with trimethoprim in animal reproduction studies; animal reproduction studies have not been conducted with polymyxin B. See individual agents. If ophthalmic agents are needed during pregnancy, the minimum effective dose should be used in combination with punctal occlusion to decrease potential exposure to the fetus (Samples 1988).
It is not known if trimethoprim or polymyxin B can be detected in breast milk following ophthalmic administration. The manufacturer recommends that caution be exercised when administering trimethoprim/polymyxin B to nursing women. See individual agents.
Also see individual agents.
Absorption: Trimethoprim and polymyxin B are systemically absorbed following ophthalmic installation. Peak concentrations were trimethoprim 0.03 mcg/mL and polymyxin B 1 unit/mL.
