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SENSORY ORGANS › OPHTHALMOLOGICALS › ANTIINFECTIVES › Antibiotics
tyrothricin
S01AA05
Forms & Strengths
- Ophthalmic drops: 0.05%
- Topical cream/ointment: 0.1% - 0.2%
- Lozenges/throat drops: 0.5 mg - 1 mg per lozenge
Adult Dosing
- Ophthalmic: Instill 1-2 drops into the affected eye(s) up to 4-6 times daily
- Topical: Apply a thin film to the affected skin area 2-3 times daily
- Oropharyngeal: Dissolve 1 lozenge slowly in the mouth every 2-3 hours as needed
Pediatric Dosing
- Ophthalmic (Children > 2 years): 1 drop into the affected eye(s) 3-4 times daily
- Topical (Children > 2 years): Apply sparingly 2 times daily
- Oropharyngeal (Children > 6 years): 1 lozenge every 3-4 hours
Indications
- Superficial bacterial infections of the eye and conjunctiva
- Minor skin infections, abrasions, and infected wounds
- Local treatment of bacterial infections of the mouth and pharynx (pharyngitis, stomatitis)
Mechanism of Action
- A mixture of antimicrobial peptides (gramicidin and tyrocidine) produced by Bacillus brevis
- Acts as a surface-active agent that disrupts bacterial cell membrane permeability
- Causes leakage of essential intracellular constituents such as potassium and amino acids, leading to cell death
- Exhibits primary activity against Gram-positive bacteria
Contraindications
- Hypersensitivity to tyrothricin or any component of the formulation
- Do not use via systemic administration or injection due to high risk of severe hemolysis and toxicity
- Avoid deep puncture wounds, severe burns, or large surface area applications
Adverse Reactions
- Local hypersensitivity reactions (contact dermatitis, itching, erythema)
- Transient stinging or burning sensation upon ophthalmic or topical application
- Irritation of the oral mucosa with lozenge use
Drug Interactions
- No clinically significant systemic drug interactions due to minimal systemic absorption when used topically, ophthalmically, or orally
- Avoid simultaneous application of other topical antibiotics on the exact same site to prevent antagonistic effects or increased local irritation
Curated Content: Needs Vetting Before Put to Clinical Use