Silver sulfadiazine is a topical antiinfective agent used to prevent and treat infections of wounds caused by second- and third-degree burns. Silver sulfadiazine possesses activity against both bacteria and yeast, while mafenide (Sulfamylon(R)) is active only against bacteria. In addition, silver sulfadiazine does not inhibit carbonic anhydrase (CA) as does mafenide and therefore can be used in situations in which CA inhibitors are contraindicated. Also, unlike silver nitrate, silver sulfadiazine does not stain dressings and tissues. Silver sulfadiazine was approved by the FDA in 1973.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Topical Administration
Cream/Ointment/Lotion Formulations:
-Silver sulfadiazine is for external use only.
-Do not use if cream has darkened in color.
-Apply to cleansed, debrided, burned areas using a sterile-gloved hand. Apply to a thickness of approx. = 1.6 mm (1/16th of an inch).
-Dressings usually are not required, but may be used.
-Treatment is normally continued until the site is ready for grafting or until satisfactory healing occurs. Unless a significant adverse reaction occurs, do not stop treatment while the threat of infection remains.
Photosensitivity can occur during therapy with silver sulfadiazine, especially when used to treat large-area burns. Other infrequently reported dermatologic reactions that can occur include skin necrosis, erythema multiforme, burning sensation on treated areas, pruritus, skin rash (unspecified), or brownish-gray skin discoloration. Stevens-Johnson syndrome, toxic epidermal necrolysis, and exfoliative dermatitis have been reported in a few cases with sulfonamides.
Several cases of transient leukopenia have been reported in patients receiving silver sulfadiazine therapy, which is primarily characterized by decreased neutrophil count. Maximal white blood cell depression occurs within 2-4 days after therapy begins and rebound to normal concentrations follows onset within 2-3 days. Recovery is not influenced by continuation of therapy. Hemolysis may occur in patients with glucose 6-phosphate dehydrogenase deficiency. Other adverse effects that have been reported in a few cases with sulfonamides and could occur when silver sulfadiazine is applied to large areas of the body and is absorbed systemically include blood dyscrasias (agranulocytosis, aplastic anemia,thrombocytopenia, and hemolytic anemia), adverse gastrointestinal effects, nervous system effects, hepatitis, and hepatic necrosis.
Interstitial nephritis has occurred infrequently in patients receiving silver sulfadiazine. A few cases of toxic nephrosis have been reported with the use of sulfonamides.
Fungal proliferation in and below the eschar may occur with silver sulfadiazine use; however, the incidence of clinically reported fungal superinfection is low.
Silver sulfadiazine is contraindicated in patients with sulfonamide hypersensitivity or sensitivity to any of the components of the commercial product.
Silver sulfadiazine should be used with caution in patients with hepatic disease or impairment because sulfonamides can cause hepatitis. Discontinuation of therapy may be necessary if hepatic impairment occurs during treatment.
Silver sulfadiazine should be used with caution in patients with renal disease or renal impairment; if decreased elimination occurs, discontinuation of therapy may be necessary.
Silver sulfadiazine should be used with caution in patients with leukopenia, thrombocytopenia, or other hematological disease because sulfonamides can cause these and other blood dyscrasias.
Intramuscular injections should be administered cautiously to patients receiving silver sulfadiazine. IM injections may cause bleeding, bruising, or hematomas due to platelet effects secondary to silver sulfadiazine therapy.
Silver sulfadiazine should be used with caution in patients with glucose 6-phosphate dehydrogenase (G6PD) deficiency because sulfonamides can cause hemolytic anemia in patients with G6PD deficiency.
Silver sulfadiazine should be used with caution in patients with porphyria because sulfonamides can precipitate porphyria.
Due to the potential for the development of kernicterus, silver sulfadiazine use is contraindicated in neonates or infants less than 2 months of age. Premature infants may be especially prone to the development of hyperbilirubinemia and/or kernicterus. Sulfonamides compete with bilirubin for binding to plasma albumin. In utero, the fetus can clear free bilirubin by the placental circulation; but after birth, this mechanism for removal of unbound bilirubin is no longer available. Unbound bilirubin can cross the blood-brain barrier, leading to kernicterus. Safe and effective use of silver sulfadiazine in children have not been established.
Silver sulfadiazine is classified in FDA pregnancy category B. According to the manufacturer, it is contraindicated in near-term pregnancy because sulfonamides may promote kernicterus in the newborn by displacing bilirubin from plasma proteins. Sulfonamides can displace bilirubin from protein binding sites and theoretically precipitate kernicterus in newborns. While this adverse reaction has occurred when a sulfonamide was administered directly to the newborn, it has not been demonstrated in a newborn when exposed to the drug in utero. Since silver sulfadiazine is administered topically, it seems even less likely than systemically administered sulfonamides to invoke this adverse reaction. Nevertheless, sulfonamides should be used with caution during near term pregnancy because of the potential risk of causing kernicterus in newborns.
According to the manufacturer, because of the possibility for serious adverse reactions in nursing infants from sulfonamides, silver sulfadiazine should not be used during breast-feeding. It is not known whether it is excreted in human milk. However, sulfonamides are known to be excreted in human milk, and all sulfonamide derivatives are known to increase the possibility of kernicterus. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.
Per the manufacturer, this drug has been shown to be active against most strains of the following microorganisms either in vitro and/or in clinical infections: Acinetobacter calcoaceticus, Candida albicans, Citrobacter sp., Corynebacterium diphtheriae, Enterobacter cloacae, Enterobacter sp., Enterococcus sp., Escherichia coli, Klebsiella sp., Morganella morganii, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, Pseudomonas aeruginosa, Serratia sp., Staphylococcus aureus (MSSA), Staphylococcus epidermidis, Stenotrophomonas maltophilia, Streptococcus sp.
NOTE: The safety and effectiveness in treating clinical infections due to organisms with in vitro data only have not been established in adequate and well-controlled clinical trials.
For wound management including the treatment of burn wound infection and burn wound infection prophylaxis in persons with second- and third-degree burns:
Topical dosage:
Adults: Apply a thickness of approximately one-sixteenth inch to the affected area(s) topically once or twice daily until healing has occurred or the wound is ready for grafting; reapply as necessary if removed by activity or hydrotherapy.
Infants, Children, and Adolescents 2 months to 17 years: Apply a thickness of approximately one-sixteenth inch to the affected area(s) topically once or twice daily until healing has occurred or the wound is ready for grafting; reapply as necessary if removed by activity or hydrotherapy.
Maximum Dosage Limits:
-Adults
2 applications/day; additional applications may be necessary if cream is removed by activity.
-Elderly
2 applications/day; additional applications may be necessary if cream is removed by activity.
-Adolescents
2 applications/day; additional applications may be necessary if cream is removed by activity.
-Children
2 applications/day; additional applications may be necessary if cream is removed by activity.
-Infants
>= 2 months: 2 applications/day; additional applications may be necessary if cream is removed by activity.
-Neonates
< 2 months: Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Sulfonamides may cause hepatic impairment; use with caution in hepatic disease. Discontinuation of treatment may be needed if hepatic impairment occurs with treatment.
Patients with Renal Impairment Dosing
Sulfadiazine may accumulate with renal impairment. Accumulation will depend on the body surface area involved and the extent of tissue damage.
*non-FDA-approved indication
Collagenase: (Contraindicated) Silver sulfadiazine should not be used with the proteolytic enzymes collagenase, papain, or sutilains because heavy metals such as silver inactivate these enzymes.
Keratinocytes; Fibroblasts; Collagen: (Major) Avoid the use of silver-containing antimicrobials or dressing (such as silver sulfadiazine) in patients receiving treatment with keratinocytes and dermal fibroblast collagen. Administering these drugs together may reduce wound repair and regeneration. In vitro data suggest silver may decrease the viability of keratinocytes and human dermal fibroblasts.
Sulfacetamide: (Major) Topical and ophthalmic sulfonamides are incompatible with preparations containing silver. Sulfacetamide sodium should not be applied to the same sites as products containing silver salts, including preparations such as silver nitrate, silver sulfadiazine, or mild silver protein.
Sulfacetamide; Sulfur: (Major) Topical and ophthalmic sulfonamides are incompatible with preparations containing silver. Sulfacetamide sodium should not be applied to the same sites as products containing silver salts, including preparations such as silver nitrate, silver sulfadiazine, or mild silver protein.
The exact mechanism by which silver sulfadiazine exerts its antiinfective activity is unknown. Both free silver and the sulfonamide moiety may exert activity, but the drug does not inhibit folic acid synthesis as other sulfonamides do. Silver sulfadiazine disrupts bacteria by damaging the cell membrane and the cell wall rather than by inhibiting folic acid synthesis.
Silver sulfadiazine has a wide spectrum of bactericidal activity against both gram-positive and gram-negative organisms. Organisms that are susceptible to topical silver sulfadiazine include Staphylococcus aureus, S. epidermidis, beta-hemolytic streptococci, Klebsiella, Escherichia coli, Enterobacter (including E. cloacae), Citrobacter, Proteus, Pseudomonas, Morganella morganii, Providencia, Serratia, and Candida albicans.
Silver sulfadiazine is administered topically. Once absorbed, sulfadiazine is distributed into most body tissues, and it appears to freely cross cell membranes. Sulfadiazine is metabolized by the liver to an N-acetyl derivative, glucuronide, and other metabolites, which are then excreted in the urine along with unchanged drug. Within 72 hours, 60-80% of the absorbed drug can be collected in the urine either as metabolites or unchanged drug.
-Route-Specific Pharmacokinetics
Topical Route
Silver sulfadiazine is not absorbed through intact skin. In contact with body fluids, it is converted by sulfhydryl groups and proteins to free sulfadiazine, which can be systemically absorbed, especially when applied to second- or third-degree burns. Systemic concentrations of sulfadiazine are detectable in some patients. Roughly 10% of sulfadiazine can be absorbed, while only 1% of free silver is absorbed. In the treatment of patients with extensive body surface area involvement, serum sulfa concentrations may reach therapeutic levels (8-12 mcg/ml).
-Special Populations
Pediatrics
Absorption of sulfadiazine may be higher in young infants <= 2 months of age.