Silver Sulfadiazine

Exactly how Silver Sulfadiazine kills bacteria hasn't been fully worked out. After the bacteria are exposed to the drug, their cell membrane changes: the cell becomes distorted and enlarged, and the cell wall membrane gets weaker. Sensitive strains also become less viable. The silver sulfadiazine molecule breaks apart, and the silver part binds to the bacterial cells. The belief is that once the silver part has passed through the cell wall, it attaches to deoxyribonucleic acid (DNA) and stops the bacteria from multiplying.

Mammalian cells contain approximately 100 times more DNA than bacterial cells. So it is thought that the ratio of silver sulfadiazine to bacterial DNA is high enough to stop bacterial division, while the ratio to epithelial DNA is low enough that epithelial cells can still regenerate. The sulfadiazine part adds a bacteriostatic action against sensitive organisms as well.

In adults, up to 10% of the sulfadiazine may be absorbed, and 60 to 85% of the absorbed amount is passed out in the urine. In children with burns covering 13% of body surface area, the urinary sulfadiazine concentration was 31.8 mg/L.