Gramicidin D

Summary

Gramicidin D is a mixture of linear gramicidins (gramicidin A, B, and C) produced by Bacillus brevis. It is used topically as an antimicrobial agent, primarily in ophthalmic and skin preparations combined with other antibiotics (e.g., neomycin, polymyxin B) for treatment of superficial infections. It is too toxic for systemic use due to hemolytic activity.

Mechanism of Action

Forms cation-selective transmembrane channels (pores) in bacterial membranes, disrupting the electrochemical gradient by allowing unrestricted movement of monovalent cations (Na+, K+, H+), leading to membrane depolarization, loss of ion homeostasis, and bacterial cell death. Active primarily against gram-positive bacteria.

Routes of Administration

Goals & Uses

• Treatment of superficial skin infectionsAntimicrobialModerate
• Treatment of superficial ocular bacterial infectionsAntimicrobial / OphthalmicHigh
• Prevention of gram-positive bacterial colonizationAntimicrobial ProphylaxisModerate

Contraindications

• Systemic administrationRoute Of AdministrationHigh
• Hypersensitivity to gramicidin or formulation excipientsAllergy / ImmunologyHigh
• Use in perforated tympanic membrane (otic use)Anatomical / SafetyHigh

Adverse Effects

• HemolysisHematologicRare
• Contact dermatitis / hypersensitivityImmunologicUncommon
• Local irritation (stinging, burning)Local ReactionCommon
• NephrotoxicityRenalRare

Drug Interactions

• Polymyxin B (combination product)Low
• Neomycin (combination product)Low

Population Constraints

• Pregnant womenReproductiveRelative
• Pediatric patients (ophthalmic use)AgeRelative
• Patients with history of antibiotic hypersensitivityAllergyRelative

Regulatory Status

• European UnionApprovedApproved: Superficial ocular and skin infections (combination preparations)Present in approved combination ophthalmic and topical products across EU member states.
• United StatesApprovedApproved: Superficial ocular bacterial infections (ophthalmic combination products), Minor skin infections (topical combination products)Approved as a component of OTC and Rx combination topical/ophthalmic products (e.g., with neomycin and polymyxin B). Not approved as a standalone systemic drug.
• United KingdomApprovedApproved: Superficial ocular infections, Otitis externa (combination products, intact tympanic membrane only)Available in combination products such as Sofradex (gramicidin + framycetin + dexamethasone) for ophthalmic and otic use.

Approved as a topical/ophthalmic antimicrobial component in multi-ingredient OTC and prescription combination products in the US and EU. Not approved as a standalone systemic agent due to hemolytic and nephrotoxic properties. Included in various branded ophthalmic combination products.

Evidence & Sources

No sources recorded yet.