Introduction

Silver sulfadiazine is a sulfa derivative topical antibacterial used primarily on second- and third-degree burns.

Uses

Silver sulfadiazine is a topical sulfonamide antibiotic that acts on the bacterial cell wall and cell membrane; approved for the treatment of burns.

Indicated as an adjunct for the prevention and treatment of wound sepsis in patients with second- and third-degree burns.

Associated Conditions

Wound Infections

Pharmacodynamics

Silver sulfadiazine has broad antimicrobial activity. It is bactericidal for many gram- negative and gram-positive bacteria as well as being effective against yeast. Silver sulfadiazine is not a carbonic anhydrase inhibitor and may be useful in situations where such agents are contraindicated.

Mechanism of Action

Studies utilizing radioactive micronized silver sulfadiazine, electron microscopy, and biochemical techniques have revealed that the mechanism of action of silver sulfadiazine on bacteria differs from silver nitrate and sodium sulfadiazine. Silver sulfadiazine acts only on the cell membrane and cell wall to produce its bactericidal effect. A specific mechanism of action has not been determined, but silver sulfadiazine's effectiveness may possibly be from a synergistic interaction, or the action of each component. Silver is a biocide, which binds to a broad range of targets. Silver ions bind to nucleophilic amino acids, as well as sulfhydryl, amino, imidazole, phosphate, and carboxyl groups in proteins, causing protein denaturation and enzyme inhibition. Silver binds to surface membranes and proteins, causing proton leaks in the membrane, leading to cell death. Sulfadiazine is a competitive inhibitor of bacterial para-aminobenzoic acid (PABA), a substrate of the enzyme dihydropteroate synthetase. The inhibited reaction is necessary in these organisms for the synthesis of folic acid.

Absorption

Very limited penetration through the skin. Only when applied to very large area burns is absorption into the body generally an issue.

Toxicity

Acute oral toxicity (LD50) in rat is 10001 mg/kg.

Food Interactions

No interactions found.

Dosage

The burn wounds are cleansed, and Silver Sulfadiazine is applied over the burn wound. The burn areas should be covered with Silver Sulfadiazine at all times. The cream should be applied once to twice daily to a thickness of approximately 1/16 inches or 1.5 mm. Whenever necessary; the cream should be reapplied to any areas from which it has been removed by patient activity. If individual patient requirements make dressings necessary, they may be used. Reapplication should be ensured immediately after hydrotherapy. Treatment with Silver Sulfadiazine should be continued until satisfactory healing is occurred, or until the burn site is ready for grafting. The drug should not be withdrawn from the therapeutic regimen while there remains the possibility of infection except if a significant adverse reaction occurs.

Medical review

Last reviewed: 24 Jul 2026

Medically reviewed by:

This is general information, not personal medical advice. Consult a doctor before taking any medicine.