Silver sulfadiazine
Silver sulfadiazine is a topical antimicrobial agent widely used in veterinary medicine for the treatment and prevention of infection in second- and third-degree burns, as well as other superficial skin infections and wounds. **Clinical Pearl:** It is highly effective against a broad spectrum of bacteria, including *Pseudomonas aeruginosa*, and some yeasts. It is particularly valued for burn management due to its soothing cream base and broad-spectrum efficacy.
Mechanism: Slowly releases **silver ions** in concentrations that are toxic to bacteria and yeasts. The **sulfadiazine** component also provides local anti-infective qualities by inhibiting bacterial folic acid synthesis. → Silver ions bind to bacterial DNA and cell membranes → disruption of cellular metabolism and structural integrity → cell death. → Sulfadiazine competitively inhibits **dihydropteroate synthase** → prevents bacterial folic acid synthesis.
Dosing by species
- Burns and superficial wound infections · Apply a thin layer (approx 1.5 mm thick) to the affected area · topical · sid to bid · Until healing is satisfactory · Clean and debride wound before application. Apply using sterile technique.
- Burns and superficial wound infections · Apply a thin layer (approx 1.5 mm thick) to the affected area · topical · sid to bid · Until healing is satisfactory · Clean and debride wound before application. Apply using sterile technique.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Hypersensitivity to sulfonamides
- Use in pregnant or premature animals (theoretical risk of kernicterus)
Adverse effects
- Local irritation
- Erythema
- Skin discoloration (argyria) with prolonged use
- Delayed wound healing (in some cases)
Drug interactions
- Topical proteolytic enzymes (e.g., collagenase) · Silver may inactivate the enzymes, reducing their debriding efficacy. · moderate
- Cimetidine · May increase the risk of leukopenia if significant systemic absorption occurs. · minor
Monitoring
- Wound healing progress
- Signs of local irritation or hypersensitivity
- Complete blood count (CBC) if applied to very large areas for prolonged periods (due to theoretical risk of leukopenia)
Overdose
Overdose is highly unlikely with topical application. Ingestion of large amounts (e.g., if a pet licks a large treated area) may cause mild gastrointestinal upset or, rarely, systemic sulfonamide toxicity (crystalluria). Treatment is symptomatic and supportive.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.