Mafenide acetate solution (Sulfamylon, Mylan) was approved by the FDA on June 5, 1998 as an antimicrobial therapy for burn wounds after being used in clinical practice for 60 years.
Mafenide acetate solution was marketed between 1948 and 1971. After 1971, mafenide acetate was used under a series of compassionate use INDs. A cream form of the drug was marketed by Dow B. Hickam starting in 1985, but the solution was seen as being more effective for the treatment of severe burns. Dow B. Hickam was acquired by Mylan in 1992.
Mylan argued that traditional clinical studies involving the use of placebo controls would be unethical for mafenide acetate solution. The FDA agreed and allowed the submission of an NDA based on animal data and data collected after a prolonged period of compassionate use exemptions. A Phase IV study will be conducted to examine efficacy and to compare mafenide acetate to other topical antibiotic regimens used in burn patients.
How It Works
Mafenide has a broad bacteriostatic action and is effective against both gram- negative and gram-positive bacteria. Its mechanism of action is not known, but is different from that of the sulfonamides.
Sulfamylon: Clinical Tips
Sulfamylon will be supplied as a powder to be reconstituted with sterile water or saline and filtered prior to use. For antibacterial therapy in burn patients with autografts, the graft should be covered with gauze and the dressing wetted with the mafenide solution. The dressing should be secured with a bolster dressing, wrapped as appropriate, and kept wet by irrigating every 4 hours or by moistening the gauze as needed with the mafenide solution. The wound dressing may be left undisturbed for up to 5 days until vascularization of the graft has occurred. The safety and efficacy of mafenide solution for more than 5 days has not been established.
Within 4 hours after topical application, approximately 80% of the mafenide acetate solution is delivered to the burn tissue. After absorption, mafenide acetate is rapidly metabolize to p-carboxybenzenesulfonamide, an inactive product that is cleared through the kidneys.
Both mafenide acetate and its metabolite inhibit carbonic anhydrase, so close monitoring of acid-base balance is indicated in patients with impaired renal function. In addition, fatal hemolytic anemia with disseminated intravascular coagulation associated with a glucose-6-phosphate dehydrogenase deficiency was reported after mafenide therapy.
Mafenide was not teratogenic in rats when administered at doses up to 600 mg/kg/day. No adequate teratology studies were done in non-rodent species, so mafenide should be used in pregnancy only if its benefit justifies the potential risk to the fetus. Mafenide has been shown to be safe and effective in children between the ages of 3 months and 16 years. No clinical data have been collected for geriatric patients.
Adverse events following administration of mafenide include dermatologic and allergic reactions as well as respiratory or metabolic events. The dermatologic and allergic reactions include pain, burning, rash, and pruritis localized to the treated area. in addition, erythema, skin maceration, facial edema, swelling, hives, blisters, and eosinophilia have been reported.
Respiratory and metabolic disorders following mafenide therapy include tachypnea, hyperventilation, decrease in pCO2, metabolic acidosis, and increases in serum chloride.
Mafenide acetate solution should not be given to patients who are hypersensitive to mafenide acetate and should be used with caution in patients with acute renal failure.