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RESPIRATORY SYSTEM › THROAT PREPARATIONS › THROAT PREPARATIONS › Antibiotics
tyrothricin
R02AB02
Forms & Strengths
- Throat spray 0.5 mg/mL
- Lozenge 0.5 mg per lozenge
- Ear drops 0.5 mg/mL
- Ointment 0.2% w/w (2 mg/g)
- Nasal spray 0.5 mg/mL
Adult Dosing
- Throat spray: 1-2 sprays (0.5 mg) every 2‑3 h, max 6 sprays/day
- Lozenge: 1 lozenge (0.5 mg) dissolved slowly, up to 6 per day
- Ear drops: 3‑4 drops in each ear twice daily for 7 days
- Ointment: apply thin layer to affected skin 2‑3 times daily
- Nasal spray: 1‑2 sprays per nostril twice daily
Pediatric Dosing
- Children ≥2 yr: lozenge 0.25 mg (half‑strength) 3‑4 per day
- Children 2‑12 yr: throat spray 1 spray (0.5 mg) every 4 h, max 4 sprays/day
- Children <2 yr: not recommended except under physician supervision
- Ear drops: 2‑3 drops in each ear twice daily for 5‑7 days
- Ointment: thin layer to skin 2 times daily
Indications
- Acute bacterial pharyngitis
- Oral mucosal ulcerations
- Dental infections
- External otitis (topical)
- Minor superficial skin infections
- Prophylaxis of postoperative throat infections
Mechanism of Action
- Mixture of polypeptide antibiotics (tyrocidine, gramicidin) that insert into bacterial membranes
- Disrupts ion gradients, causing rapid cell lysis
- Broad activity against gram‑positive cocci and some gram‑negative organisms
Contraindications
- Known hypersensitivity to tyrothricin, gramicidin, or any excipient
- History of severe allergic reaction to related polypeptide antibiotics
- Systemic use – formulation is for topical/oral mucosal use only
Adverse Reactions
- Local irritation or burning of mucosa/skin
- Altered taste or transient numbness of throat
- Mild erythema or rash at application site
- Rare hypersensitivity reactions including urticaria or anaphylaxis
- Otic discomfort if used excessively in ear
Drug Interactions
- No clinically significant systemic interactions (topical use)
- Concurrent ototoxic drugs may increase ear irritation
- Avoid simultaneous use with other topical antibiotics to limit resistance
- Potential additive nephrotoxicity with systemic aminoglycosides (theoretical, not observed with topical use)
Curated Content: Needs Vetting Before Put to Clinical Use