The mechanism of silver sulfadiazine's antibacterial action has not been fully elucidated. After exposure to the drug, structural changes in the bacterial cell membrane occur, including distortion and enlargement of the cell and a weakening of the cell wall membrane. This is accompanied by reduced viability in sensitive strains due to interference with macromolecular synthesis. The sulfadiazine moiety also provides a bacteriostatic action against sensitive organisms.
In adults, up to 10% of the sulfadiazine may be absorbed and 60-85 % of the absorbed amount is excreted in the urine. In children with 13 % body surface area burns, the urinary sulfadiazine concentration was 31.8 mg/L.
INDICATIONS AND CLINICAL USE
Flamazine (silver sulfadiazine cream) is indicated for the treatment of leg ulcers, burns, skin grafts, incisions and other clean lesions, abrasions, minor cuts and wounds.
Flamazine cream is especially indicated in the treatment and prophylaxis of infection in serious burn victims.
Sulfonamide therapy is known to increase the possibility of kernicterus. Flamazine cream should not be used in pregnant females at term, in premature infants, or in newborn infants during the first months of life.
Flamazine cream should not be used on patients with a known sensitivity to any of its components.
Sensitization to topically applied silver sulfadiazine is rarely predicted or proven by patch testing. Caution should be exercised in the use of Flamazine cream in individuals who have previously shown sensitization reactions to sulfonamides.
Silver sulfadiazine cream should be used with caution on patients with a history of glucose - 6 - phosphate dehydrogenase deficiency as hemolysis may occur.
When treatment with silver sulfadiazine cream involves prolonged administration and/or large burned surfaces, considerable amount of silver sulfadiazine is absorbed. Serum concentration of silver sulfadiazine may approach adult therapeutic levels (8-12 mg %).
Use of Flamazine may delay separation of burn eschar and may alter the appearance of burn wounds.
Flamazine (silver sulfadiazine cream) should be used with caution in patients with significant hepatic or renal impairment.
Leukopenia has been reported following the use of silver sulfadiazine, especially patients with large area burns. This may be a drug-related effect, and often occurs 2-3 days after treatment has commenced. It is usually self-limiting and therapy with Flamazine cream does not normally need to be discontinued, as the WBC count usually returns to the normal range in a few days. WBC counts should be closely monitored.
Use in pregnancy and lactation
The safe use of Flamazine has not been established in pregnancy or lactation. Flamazine cream should only be used in badly burned pregnant women if the benefit to the patient outweighs the risk to the foetus. Flamazine cream should not be used when the patient is near term. (SEE CONTRAINDICATIONS)
Since all sulphonamides increase the possibility of kernicterus, caution is required in nursing mothers.
Enzymatic debriding agents
Flamazine may inactivate enzymatic debriding agents; thus the concomitant use of these compounds may be inappropriate.
Oral hypoglycemic agents and Phenytoin
In patients with large area burns where serum sulfadiazine levels may approach therapeutic levels, the action of oral hypoglycemic agents and Phenytoin may be potentiated and it is recommended that blood levels be monitored.
Local reactions such as burning, itching and skin rash (e.g. eczema or contact dermatitis) may occur in about 2 % of patients.
Leukopenia has been reported in up to 3-5% of patients treated with Flamazine cream. This may be a drug-related effect, and often occurs within 48-72 hours after therapy has commenced. It is usually self-limiting and therapy with Flamazine does not usually need to be discontinued, although the blood count must be carefully monitored to ensure that it returns to normal within a few days.
There is evidence that in large area burn wounds and/or after prolonged application, systemic absorption of silver can cause clinical argyria.
Reports of renal problems have very rarely been reported in patients using topical silver sulphadiazine cream.
During the treatment of burns over large body surfaces, significant amounts of SSD are systematically absorbed. Therefore, it is possible that any adverse reactions associated with sulfonamides may occur.
SYMPTOMS AND TREATMENT OF OVERDOSAGE
In extensively burned patients or in patients suspected of showing symptoms of excessive absorption, it is important to optimally maintain fluid balance not only to prevent dehydration but also to avoid the possibility of renal impairment.
DOSAGE AND ADMINISTRATION
The burn wounds should be cleaned and Flamazine cream applied over all the affected areas to a depth of 3 - 5 mm.
One technique is to apply the cream with a sterile gloved hand and/or sterile spatula. Where necessary, the cream should be re-applied to any area from which it has been removed by patient activity.
Flamazine cream should be re-applied at least every 24 hours.
Hand burns and fingers injuries
One recommended method, which has been found successful, is to apply Flamazine cream to the burn and the whole hand is then enclosed in a clear plastic bag or glove, which is then closed at the wrist. The patient should be encouraged to move the hand and fingers. The dressing should be changed every three days or when an excessive amount of exudate has accumulated in the bag.
One acceptable method involves filling the cavity of the ulcer with Flamazine cream to a depth of at least 3-5 mm. Care should be taken to prevent the spread of the cream onto non-ulcerated areas. The cream should be followed by an absorbent pad or gauze dressing, with further application of pressure bandaging as appropriate for the ulcer. The dressing should be changed every 2 or 3 days, with cleaning and debriding being performed before application of Flamazine cream.
It is not recommended that Flamazine cream be used in leg ulcers that are very exudative.
A container of Flamazine cream should be reserved for use for a specific patient and should be discarded when no longer required.
Trade Name: Flamazine cream
U.S.A.N.: Silver Sulfadiazine
Chemical Name: Silver 2-(4-aminobenzenesulfonamido)-pyrimidine
Molecular Formula: C10 H9 N4 O2 S Ag
Molecular Weight: 357.14
Silver sulfadiazine is a light-stable white powder, very slightly soluble in water and most organic solvents, but readily soluble in nitric acid and concentrated ammonia solutions.
Flamazine cream is a white cream containing 1% w/w silver sulfadiazine in a water soluble vehicle. The pH of the cream is between 3.5-6.0.
Polysorbate 60 – vegetable grade
Polysorbate 80 – vegetable grade
Flamazine E cream is a sterile compound and contains no preservatives.
Flamazine cream is a white cream and is available in the following containers: 500 g jars, 20 g and 50 g tubes. Flamazine cream should be stored at 8º to 25ºC. 500 g jars should be discarded 24 hours after opening. Tubes of Flamazine should be discarded 7 days after opening.