SILVADENE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SILVADENE (SILVADENE).
Silver sulfadiazine exerts bactericidal activity by releasing silver ions that bind to microbial DNA and proteins, inhibiting cell wall synthesis and cell division. The sulfadiazine component provides additional bacteriostatic action by competing with para-aminobenzoic acid (PABA) to inhibit dihydropteroate synthase in folic acid synthesis.
| Metabolism | Silver is minimally absorbed and not metabolized; sulfadiazine is primarily metabolized via hepatic acetylation to N-acetylsulfadiazine, with the parent drug and metabolite excreted renally. |
| Excretion | Silver sulfadiazine applied topically results in minimal systemic absorption. The sulfadiazine component is primarily excreted renally (approximately 70% as unchanged drug and metabolites), with biliary/fecal excretion accounting for a small fraction (<10%). Silver is largely retained in tissues, not excreted. |
| Half-life | The terminal elimination half-life of sulfadiazine is approximately 10-12 hours in patients with normal renal function. Silver has a very long biological half-life (weeks to months) due to tissue deposition. |
| Protein binding | Sulfadiazine is approximately 32-56% bound to plasma proteins (primarily albumin). Silver is extensively bound to tissue proteins. |
| Volume of Distribution | Sulfadiazine: Vd approximately 0.2-0.3 L/kg, indicating distribution primarily in extracellular fluid. Silver: Vd is large (up to 10 L/kg) due to extensive tissue binding. |
| Bioavailability | Topical: Systemic bioavailability is low (<10% for sulfadiazine, negligible for silver). Not applicable for IV or oral routes as the drug is exclusively topical. |
| Onset of Action | Topical application: Onset of antimicrobial action is within 1-2 hours as sulfadiazine is released from the cream base and penetrates the wound eschar. |
| Duration of Action | Duration of action: Antimicrobial effect lasts approximately 24 hours, supporting once- or twice-daily application. Reapplication after wound cleansing is recommended. |
| Molecular Weight | 357.14 |
Apply a thin layer (approximately 1/16 inch) of 1% cream to the affected area once or twice daily. Use a sterile gloved hand. Reapply as needed to maintain coverage.
| Dosage form | CREAM |
| Renal impairment | No dose adjustment typically required for topical use; however, systemic absorption may occur. In severe renal impairment (CrCl < 30 mL/min), consider monitoring serum sulfadiazine levels and avoid prolonged use. |
| Liver impairment | No specific dose adjustment recommended for topical use; use with caution in severe hepatic impairment due to potential systemic accumulation. |
| Pediatric use | Infants and children: Apply a thin layer (1/16 inch) of 1% cream to the affected area once or twice daily. Avoid use in neonates (< 2 months) due to risk of kernicterus from sulfonamide displacement of bilirubin. |
| Geriatric use | Use same dosing as adults; monitor for local irritation and systemic adverse effects, especially in elderly with impaired renal or hepatic function. |
| 1st trimester | Avoid unless benefit outweighs risk; sulfonamides cross placenta and may cause kernicterus in neonates, but risk is low in first trimester. Use only if no alternative. |
| 2nd trimester | Use with caution; theoretical risk of kernicterus. Avoid near term. |
| 3rd trimester | Contraindicated near term (after 36 weeks) due to risk of kernicterus in newborn from sulfonamide component. |
Clinical note
Comprehensive clinical and safety monograph for SILVADENE (SILVADENE).
| Placental transfer | Sulfonamides cross the placenta; silver sulfadiazine's silver component may also transfer. Risk of kernicterus in third trimester. |
| Breastfeeding | Silver sulfadiazine is absorbed significantly only through large burn areas; minimal systemic absorption reduces risk. However, sulfadiazine is excreted in breast milk and could cause kernicterus in neonates, especially if jaundiced or G6PD deficient. Contraindicated in breastfeeding mothers with extensive burns or if infant has hyperbilirubinemia or G6PD deficiency. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to silver sulfadiazine, sulfonamides, or any componentPregnancy near term (36+ weeks)Breastfeeding if extensive burns or infant with hyperbilirubinemia/G6PD deficiencySignificant renal or hepatic impairmentUse on face or near eyes (relative; absolute avoidance on face per some guidelines)G6PD deficiency (systemic sulfonamide risk)
| Precautions | May cause leukopenia (usually reversible), fungal superinfection, and delayed wound healing. Use with caution in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to risk of hemolysis. Avoid prolonged use; monitor for signs of silver toxicity (argyria) with extensive application. Not recommended for use on pregnant women near term or on premature infants due to kernicterus risk from sulfadiazine. |
| Food/Dietary | No clinically significant food interactions. |
Loading safety data…
| Lactation Rating | L3 (Moderately Safe) - with risk of kernicterus; avoid if large burns or infant risk factors. |
| Teratogenic Risk | SILVADENE (silver sulfadiazine) is contraindicated in pregnancy at term and in premature neonates due to risk of kernicterus from sulfonamide displacement of bilirubin. In first and second trimesters, sulfonamides carry theoretical risk of teratogenicity, but human data are insufficient. Avoid use during entire pregnancy unless clearly needed. |
| Fetal Monitoring | Monitor complete blood count, renal and hepatic function in mother. Assess neonatal bilirubin levels if exposure near term. |
| Fertility Effects | No clinical data on fertility effects in humans. In animal studies, no impairment of fertility was observed. |
| Clinical Pearls | Apply a thin layer (1/16 inch) to burn wounds after debridement; avoid use on pregnant women near term or on premature infants due to risk of kernicterus from sulfonamide displacement of bilirubin; monitor for crystalluria and renal function in patients with G6PD deficiency. |
| Patient Advice | Apply a thin layer of cream to the burn wound once or twice daily. · Keep the wound covered with the cream at all times; do not let it dry out. · Do not use on large areas of skin without consulting a doctor. · Discontinue use and seek medical help if you develop a rash, itching, or difficulty breathing. · Avoid sun exposure on treated areas as it may cause skin discoloration. |