Mafenide acetate ointment 10%

Mafenide acetate ointment 10%® (mafenide acetate) For 5% Topical Solution is indicated for use as an adjunctive topical antimicrobial agent to control bacterial infection when used under moist dressings over meshed autografts on excised burn wounds.

Mafenide acetate ointment 10%® (mafenide acetate) For 5% Topical Solution: Directions for Preparation of the Solution: Mafenide acetate ointment 10%® (mafenide acetate) (mafenide acetate) For 5% Topical Solution is supplied as a sterile powder and is to be reconstituted with Sterile Water for Irrigation, USP or 0.9% Sodium Chloride Irrigation, USP. Aseptic techniques should be observed during preparation of the solution. Pre- measured quantities of 50 g of mafenide acetate powder are provided in sterile packets. The entire quantity of Mafenide acetate ointment 10%® (mafenide acetate) should be emptied into a suitable container which contains 1000 mL of Sterile Water for Irrigation, USP or 0.9% Sodium Chloride Irrigation, USP and mixed until completely dissolved. The reconstituted solution may be held up to 28 days after preparation if stored in unopened containers. ONCE A CONTAINER IS OPENED, ANY UNUSED PORTION SHOULD BE DISCARDED AFTER 48 HOURS. Store the reconstituted solution at 20° to 25°C (68° to 77°F). Limited storage periods at 15° to 30°C (59° to 86°F) are acceptable. Not for Injection - For Topical Use Only.

Directions for Use of the Solution: The grafted area should be covered with one layer of fine mesh gauze. An eight-ply bum dressing should be cut to the size of the graft and wetted with Mafenide acetate ointment 10%® (mafenide acetate) 5% SOLUTION using an irrigation syringe and/or irrigation tubing until leaking is noticeable. If irrigation tubing is used, the tubing should be placed over the bum dressing in contact with the wound and covered with a second piece of eight-ply dressing. The irrigation dressing should be secured with a bolster dressing and wrapped as appropriate. The gauze dressing should be kept wet. In clinical studies, this has been accomplished by irrigating with a syringe or injecting the solution into the irrigation tubing every 4 hours or as necessary. If irrigation tubing is not used, the gauze dressing may be moistened every 6-8 hours or as necessary to keep wet.

Wound dressings maybe left undisturbed, except for the irrigations, for up to five days. Additional soaks may be initiated until graft take is complete. Maceration of skin may result from wet dressings applied for intervals as short as 24 hours. Treatment is usually continued until autograft vascularization occurs and healing is progressing (typically occurring in about 5 days). Safety and effectiveness have not been established for longer than 5 days for an individual grafting procedure.

If allergic manifestations occur during treatment with Mafenide acetate ointment 10%® (mafenide acetate) 5% SOLUTION, discontinuation of treatment should be considered. If acidosis occurs and becomes difficult to control, particularly in patients with pulmonary dysfunction, discontinuing the soaks with the mafenide acetate solution for 24 to 48 hours may aid in restoring acid-base balance (see PRECAUTIONS section). Dressing changes and monitoring the site for bacterial growth during this interruption should be adjusted accordingly.

Mafenide acetate ointment 10%® (mafenide acetate) For 5% Topical Solution is contraindicated in patients who are hypersensitive to mafenide acetate. It is not known whether there is cross sensitivity to other sulfonamides.

WARNINGS

Fatal hemolytic anemia with disseminated intravascular coagulation, presumably related to a glucose-6-phosphate dehydrogenase deficiency, has been reported following therapy with mafenide acetate.

PRECAUTIONS

General: Mafenide acetate and its metabolite, p-carboxybenzenesulfonamide, inhibit carbonic anhydrase, which may result in metabolic acidosis, usually compensated by hyperventilation. In the presence of impaired renal function, high blood levels of mafenide acetate and its metabolite may exaggerate the carbonic anhydrase inhibition. Therefore, close monitoring of acid-base balance is necessary, particularly in patients with extensive second-degree or partial thickness bums and in those with pulmonary or renal dysfunction. Some bum patients treated with mafenide acetate have also been reported to manifest an unexplained syndrome of masked hyperventilation with resulting respiratory alkalosis (slightly alkaline blood pH, low arterial pC02, and decreased total C02); change in arterial p02 is variable. The etiology and significance of these findings are unknown.

Mafenide acetate should be used with caution in bum patients with acute renal failure.

Fungal colonization may occur concomitantly with reduction of bacterial growth in the bum wound. However, systemic fungal infection through the infected bum wound is rare.

Carcinogenesis, Mutagenesis, Impairment of Fertility:

No long-term animal studies have been performed to evaluate the carcinogenic potential of mafenide acetate; however, the drug did not induce mutations in L5178Y mouse lymphoma cells at the TK locus.

Animal studies have not been performed to evaluate the potential effects of mafenide acetate on fertility.

Pregnancy: Teratogenic Effects. Pregnancy Category C: A teratology study performed in rats using oral doses of up to 600 mg/kg/day revealed no evidence of harm to the fetus due to mafenide acetate. There are no adequate data regarding the potential reproductive toxicity of mafenide acetate in a non-rodent species, nor are there adequate and well-controlled studies in pregnant women. Mafenide acetate should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers: It is not known whether mafenide acetate is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from mafenide acetate, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use: The safety and effectiveness of Mafenide acetate ointment 10%® (mafenide acetate) For 5% Topical Solution have been established in the age groups 3 months to 16 years. Geriatric Use: No studies have been conducted to specifically examine the effects of mafenide acetate on bum wounds in geriatric patients.

In the clinical setting of severe bums, it is often difficult to distinguish between an adverse reaction to mafenide acetate and bum sequelae. In a clinical study of pediatric patients with acute bums requiring autografts who received Mafenide acetate ointment 10%® (mafenide acetate) 5% SOLUTION in addition to double antibiotic solution (DAB) wound therapy (neomycin sulfate 40 mg and polymyxin B 200,000 units/liter), the incidence of rash (4.6%) and itching (2.8%) in the group which received Mafenide acetate ointment 10%® (mafenide acetate) 5% Solution was not different from that experienced with (DAB) dressings alone (5.7% and 1.3%, respectively).

From other clinical settings, a single case of bone marrow depression and a single case of an acute attack of porphyria have been reported following therapy with mafenide acetate. Fatal hemolytic anemia with disseminated intravascular coagulation, presumably related to a glucose-6-phosphate dehydrogenase deficiency, has been reported following therapy with mafenide acetate. The following adverse reactions have been reported with topical mafenide acetate therapy:

Dermatologlc and Allergic: Pain or burning sensation, rash and pruritus (often localized to the area covered by the wound dressing), erythema, skin maceration from prolonged wet dressings, facial edema, swelling, hives, blisters, eosinophilia.

Respiratory or Metabolic: Tachypnea, hyperventilation, decrease in pCOa, metabolic acidosis, increase in serum chloride.

Single oral doses of 2000 mg/kg of mafenide acetate as a 5% solution did not cause mortality or clinical symptoms of toxicity in rats.