Mitomycin

Mitomycin should be given intravenously only, using care to avoid extravasation of the compound. If extravasation occurs, cellulitis, ulceration, and slough may result. Each vial contains either mitomycin 20 mg and mannitol 40 mg or mitomycin 40 mg and mannitol 80 mg. To administer, add Sterile Water for Injection 40 mL or 80 mL, respectively. Shake to dissolve. If product does not dissolve immediately, allow to stand at room temperature until solution is obtained. After full hematological recovery (see guide to dosage adjustment) from any previous chemotherapy, the following dosage schedule may be used at 6- to 8-week intervals: 20 mg/m 2 intravenously as a single dose via a functioning intravenous catheter. Because of cumulative myelosuppression, patients should be fully reevaluated after each course of mitomycin, and the dose reduced if the patient has experienced any toxicities. Doses greater than 20 mg/m 2 have not been shown to be more effective and are more toxic than lower doses. The following schedule is suggested as a guide to dosage adjustment: Nadir After Prior Dose Percentage of Prior Dose To Be Given Leukocytes/mm 3 Platelets/mm 3 >4000 >100,000 100% 3000 to 3999 75,000 to 99,999 100% 2000 to 2999 25,000 to 74,999 70% <2000 <25,000 50% No repeat dosage should be given until leukocyte count has returned to 4000/mm 3 and platelet count to 100,000/mm 3. When mitomycin is used in combination with other myelosuppressive agents, the doses should be adjusted accordingly. If the disease continues to progress after two courses of mitomycin, the drug should be stopped since chances of response are minimal. Stability 1. Unreconstituted mitomycin stored at controlled room temperature is stable for the lot life indicated on the package. Avoid excessive heat (over 40°C). 2. Reconstituted with Sterile Water for Injection to a concentration of 0.5 mg per mL, mitomycin is stable for 14 days refrigerated or 7 days at room temperature. Protect reconstituted solution from light. 3. Diluted in various IV fluids at room temperature, to a concentration of 20 to 40 micrograms per mL: IV Fluid Stability 5% Dextrose Injection 3 hours 0.9% Sodium Chloride Injection 12 hours Sodium Lactate Injection 24 hours 4. The combination of mitomycin (5 mg to 15 mg) and heparin (1,000 units to 10,000 units) in 30 mL of 0.9% Sodium Chloride Injection is stable for 48 hours at room temperature. Procedures For Proper Handling and Disposal of anticancer drugs should be considered. Several guidelines on this subject have been published. 1-7 There is no general agreement that all of the procedures recommended in the guidelines are necessary or appropriate. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

Acute shortness of breath and severe bronchospasm have been reported following the administration of vinca alkaloids in patients who had previously or simultaneously received mitomycin. The onset of this acute respiratory distress occurred within minutes to hours after the vinca alkaloid injection. The total number of doses for each drug has varied considerably. Bronchodilators, steroids and/or oxygen have produced symptomatic relief. A few cases of adult respiratory distress syndrome have been reported in patients receiving mitomycin in combination with other chemotherapy and maintained at FlO 2 concentrations greater than 50% perioperatively. Therefore, caution should be exercised using only enough oxygen to provide adequate arterial saturation since oxygen itself is toxic to the lungs. Careful attention should be paid to fluid balance and overhydration should be avoided. Bladder fibrosis/contraction has been reported with intravesical administration (not an approved route of administration), which in rare cases has required cystectomy. Nursing Mothers It is not known if mitomycin is found in human milk. Because many drugs are found in milk, it is recommended that women receiving mitomycin not breast feed because of the potential for serious adverse reactions from mitomycin in nursing infants. Pediatric Use Safety and effectiveness in pedriatric patients have not been established.

Bone Marrow Toxicity This was the most common and most serious toxicity, occurring in 605 of 937 patients (64.4%). Thrombocytopenia and/or leukopenia may occur anytime within 8 weeks after onset of therapy with an average time of 4 weeks. Recovery after cessation of therapy was within 10 weeks. About 25% of the leukopenic or thrombocytopenic episodes did not recover. Mitomycin produces cumulative myelosuppression. Integument and Mucous Membrane Toxicity This has occurred in approximately 4% of patients treated with mitomycin. Cellulitis at the injection site has been reported and is occasionally severe. Stomatitis and alopecia also occur frequently. Rashes are rarely reported. The most important dermatological problem with this drug, however, is the necrosis and consequent sloughing of tissue which results if the drug is extravasated during injection. Extravasation may occur with or without an accompanying stinging or burning sensation and even if there is adequate blood return when the injection needle is aspirated. There have been reports of delayed erythema and/or ulceration occurring either at or distant from the injection site, weeks to months after mitomycin, even when no obvious evidence of extravasation was observed during administration. Skin grafting has been required in some cases. Renal Toxicity 2% of 1,281 patients demonstrated a statistically significant rise in creatinine. There appeared to be no correlation between total dose administered or duration of therapy and the degree of renal impairment. Pulmonary Toxicity This has occurred infrequently but can be severe and may be life-threatening. Dyspnea with a nonproductive cough and radiographic evidence of pulmonary infiltrates may be indicative of mitomycin-induced pulmonary toxicity. If other etiologies are eliminated, mitomycin therapy should be discontinued. Steroids have been employed as treatment of this toxicity, but the therapeutic value has not been determined. A few cases of adult respiratory distress syndrome have been reported in patients receiving mitomycin in combination with other chemotherapy and maintained at FlO 2 concentrations greater than 50% perioperatively. Hemolytic Uremic Syndrome (HUS) This serious complication of chemotherapy, consisting primarily of microangiopathic hemolytic anemia (hematocrit ≤ 25%), thrombocytopenia (≤ 100,000/mm 3), and irreversible renal failure (serum creatinine ≥ 1.6 mg/dL) has been reported in patients receiving systemic mitomycin. Microangiopathic hemolysis with fragmented red blood cells on peripheral blood smears has occurred in 98% of patients with the syndrome. Other less frequent complications of the syndrome may include pulmonary edema (65%), neurologic abnormalities (16%), and hypertension. Exacerbation of the symptoms associated with HUS has been reported in some patients receiving blood product transfusions. A high mortality rate (52%) has been associated with this syndrome. The syndrome may occur at any time during systemic therapy with mitomycin as a single agent or in combination with other cytotoxic drugs. Less frequently, HUS has also been reported in patients receiving combinations of cytotoxic drugs not including mitomycin. Of 83 patients studied, 72 developed the syndrome at total doses exceeding 60 mg of mitomycin. Consequently, patients receiving ≥ 60 mg of mitomycin should be monitored closely for unexplained anemia with fragmented cells on peripheral blood smear, thrombocytopenia, and decreased renal function. The incidence of the syndrome has not been defined. Therapy for the syndrome is investigational. Cardiac Toxicity Congestive heart failure, often treated effectively with diuretics and cardiac glycosides, has rarely been reported. Almost all patients who experienced this side effect had received prior doxorubicin therapy. Acute Side Effects Due to Mitomycin were fever, anorexia, nausea, and vomiting. They occurred in about 14% of 1,281 patients. Other Headache, blurring of vision, confusion, drowsiness, syncope, fatigue, edema, thrombophlebitis, hematemesis, diarrhea, and pain. These did not appear to be dose related and were not unequivocally drug related. They may have been due to the primary or metastatic disease processes. Malaise and asthenia have been reported as part of postmarketing surveillance. Bladder fibrosis/contraction has been reported with intravesical administration (see PRECAUTIONS).