Tyrothricin

Summary

Tyrothricin is a mixture of cyclic peptide antibiotics (primarily gramicidin and tyrocidine) produced by Bacillus brevis. It is used topically and as a throat lozenge for local treatment of bacterial infections of the mouth, throat, and skin. It is too toxic for systemic use due to hemolytic properties but is effective locally against gram-positive bacteria.

Mechanism of Action

Disrupts bacterial cell membrane integrity; gramicidin component forms ion channels in bacterial membranes causing depolarization and cell death, while tyrocidine component disrupts membrane phospholipid bilayer structure, leading to leakage of intracellular contents.

Routes of Administration

Goals & Uses

• Treatment of sore throat and oral infectionsAntimicrobial / Local ENTModerate
• Topical skin infection treatmentDermatology / AntimicrobialModerate
• Oral cavity antisepsisDental / AntimicrobialLow

Contraindications

• Known hypersensitivity to tyrothricin or its componentsAllergyHigh
• Application to large open wounds or deep woundsWound TypeModerate
• Systemic administrationRoute Of AdministrationHigh

Adverse Effects

• Local irritation or burning sensationLocal ReactionUncommon
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• HemolysisHematologicRare
• Allergic contact dermatitisImmunologicalRare

Drug Interactions

• Other topical antibioticsLow

Population Constraints

• PregnancyReproductive SafetyRelative
• Patients with known hemolytic disordersHematologicalRelative
• Infants and neonatesPediatricRelative

Regulatory Status

• European UnionApprovedApproved: Local treatment of bacterial throat infections (lozenges), Topical treatment of minor skin infectionsAvailable OTC in multiple EU member states including Germany, France, and others. Marketed as lozenges and topical preparations.
• United StatesUnapprovedNot FDA-approved for any indication. Not commercially marketed in the US as a standalone product.
• United KingdomApprovedApproved: Topical/oromucosal antibacterial useAvailable in OTC throat lozenge formulations in the UK.

Approved in several European countries as an over-the-counter topical antiseptic and throat lozenge ingredient. Not systemically administered due to hemolytic toxicity. Available in Germany and other EU countries as lozenges (e.g., Tyrosur, Lemocin). Not formally approved by the FDA for any indication in the United States.

Evidence & Sources

No sources recorded yet.