Professional Drug Information > Mafenide Acetate

Mafenide (Topical)

VA CLASSIFICATION
Primary: DE101
Secondary: DE102

Commonly used brand name(s): Sulfamylon.

Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).

^†Not commercially available in Canada.

Category:


Antibacterial (topical)—

antifungal (topical)^{12}—
Note: Mafenide is a broad-spectrum antibacterial agent having an antibacterial spectrum similar to that of silver sulfadiazine. ^{07}



Indications

Note: Bracketed information in the Indications section refers to uses that are not included in U.S. product labeling.

Accepted

Burn wound infections (prophylaxis^{12}{15} and treatment^{12}{15} )—Mafenide is indicated [as a primary^{12} agent] in the topical prophylaxis and treatment of burn wound infections caused by Candida albicans^{12} (Monilia albicans) , Citrobacter species, ^{12} Enterobacter species ^{12} (including E. cloacae) , ^{12} enterococci, ^{12} Escherichia coli , ^{12} Klebsiella species, ^{12} Mima-Herellea species, ^{12} Morganella morganii^{12} (Proteus morganii) , P. mirabilis , ^{12} P. vulgaris , ^{12} Providencia rettgeri^{12} (Proteus rettgeri) , Pseudomonas aeruginosa , ^{{01} {12}} Serratia species, ^{12} Staphylococcus aureus , ^{12} S. epidermidis , ^{12} and beta-hemolytic streptococci ^{12} in patients with second- and third-degree burns. ^{{01} {03} {04} {07} {08} {09} {10}}
—[Mafenide is also indicated as a primary agent^{12} in the treatment of burn wound infections in patients having a thick eschar (e.g., in electrical burns).] ^{12}

—Not all species or strains of a particular organism may be susceptible to mafenide.


Pharmacology/Pharmacokinetics

Physicochemical characteristics:

Chemical group—
    Methylated sulfonamide ^{{01} {10}}
Molecular weight—
    246.28


Other characteristics
    Sulfonamides have certain chemical similarities to some goitrogens, diuretics (acetazolamide and thiazides), and oral antidiabetic agents ^{05}.

Mechanism of action/Effect:

Bacteriostatic for many gram-negative and gram-positive organisms, including Pseudomonas aeruginosa and certain strains of anaerobes. Unlike most sulfonamides, mafenide is not inhibited by aminobenzoates (PABA), blood, serum, or pus. Its activity is not altered by changes in acidity. Mafenide is highly soluble and diffuses into and through eschar. ^{{01} {03} {07} {08} {15}}

Topical mafenide produces a marked reduction in number of bacteria present, even in avascular tissue of second- and third-degree burns. Reduction in bacterial growth has been reported to result in spontaneous healing of deep partial-thickness burns, thus preventing their conversion to full-thickness burns. However, delayed eschar separation has occurred in some patients. ^{{01} {03} {15}}


Other actions/effects:

Mafenide and its metabolite also inhibit carbonic anhydrase activity, which may result in metabolic acidosis. However, hyperventilation usually compensates for the acidosis ^{{01} {03} {07} {08}} in normal persons. ^{12}

Absorption:

Mafenide is absorbed through devascularized areas into the systemic circulation following topical administration. ^{{01} {03} {08} {15}}

Biotransformation:

Rapidly metabolized to a nontoxic metabolite, p-carboxybenzenesulfonamide, which has no antibacterial activity. ^{{01} {03} {08}}

Time to peak concentration:

24 hours following initial application in patients with second- and third-degree burns covering approximately 35 to 70% of the total body surface. ^{03}

Elimination:
    Renal—Metabolite rapidly excreted in urine in high concentrations; however, the parent compound has not been detected in urine. ^{{01} {03} {08}}


Precautions to Consider

Cross-sensitivity and/or related problems

Patients sensitive to other sulfonamides, furosemide, thiazide diuretics, sulfonylureas, or carbonic anhydrase inhibitors may be sensitive to this medication also. ^{{02} {05} {08} {12}}

Carcinogenicity/Mutagenicity

Long-term studies in animals have not been performed to evaluate mafenide's carcinogenic or mutagenic potential. ^{01}

Pregnancy/Reproduction
Fertility—
Long-term studies in animals or humans have not been performed to evaluate mafenide's effect on fertility. ^{01}

Pregnancy—
Studies have not been done in humans. ^{{01} {03} {15}} However, use is not recommended in women of child-bearing potential unless the burn area covers more than 20% of the total body surface. ^{{01} {03}} In addition, absorbed sulfonamides may displace bilirubin from protein-binding sites in the fetal plasma, thus increasing the possibility of kernicterus in the neonate. ^{{12} {14}} Therefore, mafenide should not be used at term. ^{14}

Studies have not been done in animals. ^{{01} {03} {15}}

FDA Pregnancy Category C. ^{{01} {03}}

Breast-feeding

It is not known whether mafenide, applied topically, is distributed into breast milk. ^{{12} {15}} However, mafenide is absorbed systemically following topical application. ^{12} Caution is recommended in nursing women, since systemically administered sulfonamides are distributed into breast milk and may cause kernicterus in nursing infants. ^{{12} {14}} Also, sulfonamides may cause hemolytic anemia in glucose-6-phosphate dehydrogenase (G6PD)-deficient infants. ^{{01} {02} {03} {12}}

Pediatrics

Use is not recommended in premature or newborn infants up to 2 months ^{14} of age, since sulfonamides may cause kernicterus in these neonates. ^{{02} {05} {14}}


Geriatrics


Appropriate studies on the relationship of age to the effects of mafenide have not been performed in the geriatric population. However, no geriatrics-specific problems have been documented to date.

Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).


Risk-benefit should be considered when the following medical problems exist
Blood dyscrasias    (sulfonamides may cause or contribute to blood dyscrasias ^{{01} {02} {03} {12}})


Glucose-6-phosphate dehydrogenase (G6PD) deficiency    (sulfonamides may cause hemolytic anemia in G6PD-deficient patients ^{{01} {02}})


Metabolic acidosis or^{01}
Pulmonary function impairment or^{01}{12}
Renal function impairment^{01}{12}    (mafenide and its metabolite may inhibit carbonic anhydrase activity, causing or contributing to metabolic acidosis; pulmonary or renal function impairment may increase this risk ^{{01} {03} {08} {12}})


Sensitivity to mafenide^{01}{03}

Patient monitoring
The following may be especially important in patient monitoring (other tests may be warranted in some patients, depending on condition; » = major clinical significance):

^{12}» Acid-base balance    (mafenide and its metabolite inhibit carbonic anhydrase activity, which may result in metabolic acidosis; close monitoring of acid-base balance is recommended during therapy with mafenide, especially in patients with extensive second-degree or partial-thickness burns and in patients with pulmonary or renal function impairment ^{{01} {03}})






Side/Adverse Effects

Note: If significant absorption occurs, side/adverse effects (e.g., Stevens-Johnson syndrome, Lyell's syndrome, blood dyscrasias, crystalluria) usually seen with systemic sulfonamides may occur with mafenide therapy, although few have been reported. ^{12}
Fatal hemolytic anemia, accompanied by disseminated intravascular coagulation, has been reported with mafenide therapy. ^{{01} {03}}

The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:

Those indicating need for medical attention
Incidence less frequent
    
Allergic reaction^{{01}{03}{07}{08}{12}{16}} (itching, skin rash or redness, swelling of face or skin; wheezing or troubled breathing)

Incidence rare
    
Bleeding or oozing of skin^{01}{03}
    
metabolic acidosis^{{01}{03}{07}{08}{11}{12}} (drowsiness; nausea; rapid, deep breathing)—hyperventilation may compensate for the acidosis^{{01}{03}{08}{12}}



Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
    
Pain or burning feeling on treated area(s)^{{01}{03}{07}{08}}





Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Mafenide (Topical).

In providing consultation, consider emphasizing the following selected information (» = major clinical significance):

Before using this medication
»   Conditions affecting use, especially:
Sensitivity to mafenide, other sulfonamides, furosemide, thiazide diuretics, sulfonylureas, or carbonic anhydrase inhibitors

Pregnancy—Use is not recommended in women of child-bearing potential unless burn area covers more than 20% of total body surface; absorbed sulfonamides may increase the possibility of kernicterus in the neonate; do not use at term





Breast-feeding—May cause kernicterus in nursing infants; may cause hemolytic anemia in G6PD-deficient infants





Use in children—Not recommended in premature or newborn infants up to 2 months of age; may cause kernicterus


Proper use of this medication
To use:

• Before applying, cleansing affected area(s); removing necrotic or burned skin and other debris


• Wearing a sterile glove to apply the medication; applying a thin layer (approximately 1.5 mm) to affected area(s); keeping affected area(s) covered with the medication at all times


• Reapplying mafenide that has been removed by patient activity or washed off by bathing, showering, or use of a whirlpool bath


• After applying, covering treated area(s) with a dressing or leaving treated area(s) uncovered as desired


» Compliance with full course of therapy; continuing medication until burn has healed or is ready for skin grafting

» Proper dosing
Missed dose: Applying as soon as possible; not applying if almost time for next dose

» Proper storage

Precautions while using this medication
Regular visits to physician to check progress

Checking with physician if no improvement within a few days or weeks (for more serious burns or burns over more extensive areas)


Side/adverse effects
Signs of potential side effects, especially allergic reaction, bleeding or oozing of skin, or metabolic acidosis


General Dosing Information
Mafenide may be used concurrently with sutilains ointment without loss of enzyme activity. ^{06}

Before application of mafenide, burn wounds should be cleansed and debrided following control of shock and pain. A sterile glove should be worn to apply the medication. A thin layer (approximately 1.5 mm) of mafenide should then be applied to the affected area(s). A thicker layer is not recommended. The burn areas should be kept covered with mafenide at all times. When necessary, the medication should be reapplied to any areas from which it has been removed by patient activity or washed off by bathing, showering, or use of a whirlpool bath. ^{{01} {02} {03} {07} {08}}

Dressings, although not required, may be applied if necessary. ^{{01} {02} {03} {07} {08}}

Treatment with mafenide should be continued until satisfactory healing has occurred or until the burn site is ready for skin grafting. Therapy should not be discontinued while the possibility of infection exists, unless significant toxicity occurs. ^{{01} {02} {03} {07} {08}}

Burn patients should be bathed daily, if feasible, to aid in debridement of the burned area(s). Whirlpool baths are particularly helpful, although burn patients may be bathed in bed or in a shower. Following this, mafenide should be reapplied. ^{{01} {02} {03} {07}}

For treatment of adverse effects
Recommended treatment consists of the following

   • Administering antihistamines for allergic reaction. ^{08}
   • Discontinuing mafenide therapy for 24 to 48 hours, ^{13} continuing fluid therapy, administering sodium bicarbonate parenterally, and using assisted ventilation, if necessary, to restore acid-base balance. ^{{03} {08} {13}}


Topical Dosage Forms

MAFENIDE ACETATE CREAM USP

Usual adult and adolescent dose
Antibacterial or
Antifungal
Topical, to the affected area(s), one or two times a day, applied to a thickness of approximately 1.5 mm. ^{{01} {03} {07} {08} {15}}


Usual pediatric dose
Antibacterial or
Antifungal
Premature and newborn infants up to 2 months ^{14} of age: Use is not recommended, since sulfonamides may cause kernicterus in these neonates. ^{{02} {05}}
Infants and children 2 months ^{14} of age and over: See Usual adult and adolescent dose. ^{{01} {03}}


Strength(s) usually available
U.S.—


85 mg (base) per gram (Rx) [Sulfamylon (sodium metabisulfite) (methylparaben) (propylparaben) (edetate disodium)]

Canada—
Not commercially available. ^{17}

Packaging and storage:
Store below 40 °C (104 °F), in a tight, light-resistant container. Protect from freezing.

Auxiliary labeling:
   • For external use only.
   • Continue medicine for full time of treatment.

Additional information:
Mafenide acetate cream is available in a nonstaining, water-miscible base. It can be readily washed off with water. ^{{01} {03}}

Revised: 04/22/1994

References

1. Sulfamylon package insert (Winthrop—US), Rev 2/87, Rec 3/89.
   

2. Silver Sulfadiazine (Topical) mgh, USP DI 1990 (proposed), 11/30/88.
   

3. Sulfamylon (Winthrop). In: Krogh, CME, editor. CPS Compendium of pharmaceuticals and specialities. 23rd ed. Ottawa: Canadian Pharmaceutical Association, 1988: 876.
   

4. Indications Index review, 1985.
   

5. Sulfonamides (Systemic) mgh, USP DI 1989, 2213–20.
   

6. Travase (Flint). In: PDR Physicians' desk reference. 42nd ed. 1988. Oradell, NJ: Medical Economics Company, 1988: 963.
   

7. AMA Drug evaluations. 6th ed. Chicago: American Medical Association 1986 Sep: 1506–7.
   

8. Reynolds JEF, editor. Martindale, the extra pharmacopeia. 28th ed. London: The Pharmaceutical Press, 1982: 1467–8.
   

9. Gilman AG, Goodman LS, Rall TW, Murad F, editors. Goodman and Gilman's the pharmacological basis of therapeutics. 7th ed. New York: Macmillan, 1985: 1101.
   

10. Hoeprich, Infect Dis, 3rd ed, 231, 249, 1348-51.
    

11. Finkel AJ, editor. CMIT. Current medical information and terminology. 5th ed. Chicago: American Medical Association, 1981: 7.
    

12. Panel comments, 6/90.
    

13. Sulfamylon cream (Winthrop). In: Krogh CME, editor. CPS Compendium of pharmaceuticals and specialities. 24th ed. Ottawa: Canadian Pharmaceutical Association, 1989: 987.
    

14. Silvadene (Marion). In: PDR Physicians' desk reference. 44th ed. Oradell, NJ: Medical Economics Company, 1990: 1269–70.
    

15. Sulfamylon Cream package insert (Dow B. Hickam, Inc.—US), Rev 7/91, Rec 1/94.
    

16. Sanz de Galdeano C, Aguirre A, Oleaga JM, Goday J, Perz JL. Allergic contact dermatitis from topical mafenide. Contact Dermatitis 1993 Apr; 28: 249.
    

17. Krogh CME, editor. CPS Compendium of pharmaceuticals and specialties. 28th ed. Ottawa: Canadian Pharmaceutical Association, 1993.
    

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