Polytrim

Ophthalmological Anti-infectives

For storage information, see specific product information within the How Supplied section.

For topical ophthalmic administration only; do not use as an ocular injection.
Wash hands before and after use.
Care should be taken to avoid contamination. Do not touch the tip of the container to the eye, fingertips, or other surface. Do not share bottles between patients.
Tilt head back slightly and pull the lower eyelid down with the index finger to form a pouch. Squeeze the prescribed number of drops into the pouch and gently close eyes for 1—2 minutes. Do not blink.

erythema / Early / Incidence not known
edema / Delayed / Incidence not known
epiphora / Early / Incidence not known
superinfection / Delayed / Incidence not known

pruritus / Rapid / Incidence not known
ocular irritation / Rapid / Incidence not known
ocular pruritus / Rapid / Incidence not known
rash / Early / Incidence not known

Polytrim

Rx

Ophthalmic preparation for the treatment of acute bacterial ocular infections; Polymyxin B has activity against gram-negative aerobic bacteria, including P. aeruginosa; trimethoprim is effective against both gram-positive and gram-negative organisms.

1 drop in the affected eye(s) every 3 hours, up to 6 times daily, for 7 to 10 days.

1 drop in the affected eye(s) every 3 hours, up to 6 times daily, for 7 to 10 days.

No dosage adjustments are needed for ophthalmic topical application.

No dosage adjustments are needed for ophthalmic topical application.

There are no drug interactions associated with Polymyxin B; Trimethoprim products.

Polymyxin B Sulfate, Trimethoprim Sulfate/Polymyxin B, Trimethoprim/Polytrim Ophthalmic Sol: 1mL, 10000-1mg

6 drops/day.

6 drops/day.

6 drops/day.

6 drops/day.

>= 2 months: 6 drops/day.
< 2 months: Use not established.

Mechanism of Action:•Polymyxin B: Polymyxin B binds to phospholipids in the gram-negative bacterial cell membrane. This binding destroys bacterial membranes with a surface detergent-like mechanism and increases the permeability of the cell membrane, which results in loss of metabolites essential to bacterial existence. Polymyxin B is bactericidal against most gram-negative bacilli; however, some Proteus and Serratia species may be resistant. Polymyxin B has no in vitro activity against gram-positive organisms.•Trimethoprim: Trimethoprim interferes with folate synthesis in susceptible bacteria. Trimethoprim blocks the production of tetrahydrofolic acid from dihydrofolic acid by binding to and reversibly inhibiting dihydrofolate reductase. Trimethoprim selectively binds to the bacterial enzyme over the corresponding mammalian enzyme.

Polymyxin B and trimethoprim combinations are applied topically to the eye.

Ophthalmic Route
Blood samples following instillation of 2 drops of polymyxin B 10,000 units/ml and trimethoprim 1 mg/ml in the eye resulted in peak plasma concentrations of polymyxin B and trimethoprim of 1 unit/ml and 0.03 mcg/ml, respectively. Polymyxin B does not penetrate significantly into the aqueous humor of the eye even when inflammation is present.

Polymyxin B; trimethoprim ophthalmic products have not been studied in pregnant women. It is not known if polymyxin B can cause fetal harm. Trimethoprim has been shown to be teratogenic in animals when given in high systemic doses. Trimethoprim may interfere with folic acid metabolism and therefore, should only be used during pregnancy if the potential benefit justifies the risk. However, minimal systemic absorption occurs from topical ophthalmic administration.

It is not known if polymyxin B; trimethoprim, when given for ocular infections, is excreted in breast milk. The manufacturer recommends caution should be exercised if this combination is given to a woman who is nursing her infant. However, in 11 volunteers, peak serum concentrations were approximately 0.03 microg/mL trimethoprim and 1 unit/mL polymyxin B after 2 drops of the ophthalmic solution were administered. Oral absorption of any polymyxin by the nursing infant would me minimal. Additionally, trimethoprim is considered usually compatible by the American Academy of Pediatrics (AAP). To minimize the amount of drug that reaches the systemic circulation and breast milk, apply pressure over the tear duct by the corner of the eye for 1 minute after ophthalmic administration. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally administered drug, healthcare providers are encouraged to report the adverse effect to the FDA.