Trimethoprim Sulfate – Polymyxin B Sulfate
Action And Clinical Pharmacology: When used topically, trimethoprim and polymyxin B are rarely sensitizing and absorption through intact skin and mucous membrane is insignificant.
Blood samples were obtained from 11 human volunteers at 20 minutes, 1 hour and 3 hours following instillation of 2 drops of a solution containing 1 mg trimethoprim and 10 000 units of polymyxin B/mL. On the 9 previous days, each patient received 2 drops of solution 4 times/day.
No detectable levels of drugs were noted with assay limits of 0.03 mg trimethoprim/mL of serum and 1 unit polymyxin B/mL of serum.
Indications And Clinical Uses: Polytrim is active against the following gram-positive and gram-negative organisms which may be associated with surface ocular bacterial infections:
Gram-positive: S. aureus, S. epidermidis, Streptococcus spp. (Group A beta-hemolytic and non-hemolytic), S. pneumoniae.
Gram-negative: P. aeruginosa, H. influenzae, H. aegyptius, E. coli, K. pneumoniae, P. mirabilis (indole-positive), Proteus spp. (indole-negative), E. aerogenes, C. freundii, C. diversus, A. calcoaceticus, M. lacunata (some strains), S. marcescens.
Sensitivity tests should be performed whenever possible to determine the optimum therapy for any given infection.
Polytrim is indicated for the following surface ocular bacterial infections when caused by susceptible strains of the above organisms: acute bacterial conjunctivitis, blepharitis, blepharoconjunctivitis.
Contra-Indications: In patients with known hypersensitivity to any of its components.
Manufacturers’ Warnings In Clinical States: Not for injection into the eye. If a sensitivity reaction to Polytrim occurs, discontinue use. Polytrim is not indicated for the prophylaxis or treatment of ophthalmia neonatorum.
Precautions: General: As with other antimicrobial preparations, prolonged use may result in overgrowth of nonsusceptible organisms, including fungi. If superinfection occurs, appropriate therapy should be initiated.
Information for the Patient: Avoid contamination of the dropper with material from the eye, fingers, or other source. This precaution is necessary to maintain sterility of the drops.
If redness, irritation, swelling or pain persists or increases, discontinue use immediately and contact your physician.
Children: The safety and effectiveness in children below the age of 2 months has not been established (see Warnings).
Adverse Reactions: The most frequent adverse reaction to Polytrim is local irritation consisting of transient burning or stinging, itching or increased redness upon instillation. These reactions occur in less than 4 of 100 patients treated. Polytrim has a low incidence of hypersensitivity reactions (less than 2 of 100 patients treated) consisting of lid edema, itching, increased redness, tearing and/or circumocular rash.
Dosage And Administration: Adults: In mild to moderate infections, instill 1 or 2 drops in the affected eye every 3 hours (maximum of 6 doses/day) for a period of 7 to 10 days.
More severe infections may require instillation of 1 or 2 drops every hour until improvement is observed and then reduced to 1 or 2 drops every 3 hours.
Children: Children over 2 months of age are treated in the same manner as adults.
Availability And Storage: Each mL of sterile ophthalmic solution contains: trimethoprim (as sulfate) 1 mg, polymyxin B (as sulfate) 10 000 units. Nonmedicinal ingredients: benzalkonium chloride 0.004% (as preservative), sodium chloride, sodium hydroxide or sulfuric acid and water for injection. Plastic drop-dose dispensers of 10 mL. Store at 15 to 25°C. Protect from light.
POLYTRIM Allergan Trimethoprim Sulfate – Polymyxin B Sulfate Antibacterial Agent