mitomycin
Pharmacologic class: Antitumor antibiotic
Therapeutic class: Antineoplastic
Pregnancy risk category C
FDA Box Warning
• Give under supervision of physician experienced in cancer chemotherapy, in facility with adequate diagnostic and treatment resources.
• Most common and severe toxic effect is bone marrow suppression.
• Some patients receiving systemic drug have experienced hemolytic uremic syndrome, a serious complication consisting primarily of microangiopathic hemolytic anemia, thrombocytopenia, and irreversible renal failure. Syndrome may arise at any time during systemic therapy, but most cases occur at doses of 60 mg or higher. Blood product transfusion may exacerbate symptoms.
Action
Selectively inhibits DNA synthesis by causing cross-linking of DNA strands and suppressing RNA and protein synthesis, resulting in cell death
Availability
Injection: 5-mg, 20-mg, and 40-mg vials
Indications and dosages
➣ Disseminated adenocarcinoma of stomach or pancreas (given with other chemotherapeutic agents); palliative treatment when other therapies fail
Adults: 20 mg/m2 I.V. as a single dose. Repeat cycle q 6 to 8 weeks, adjusting dosage if necessary.
Dosage adjustment
• Reduced white blood cell or platelet count
Contraindications
• Hypersensitivity to drug
• Thrombocytopenia, coagulation disorders, increased bleeding tendency
Precautions
Use cautiously in:
• active infections, decreased bone marrow reserve, impaired hepatic function
• history of pulmonary disorders
• elderly patients
• pregnant or breastfeeding patients.
Administration
☞ Follow facility policy for handling, administering, and disposing of mutagenic, teratogenic, and carcinogenic drugs.
• Reconstitute 5-mg vial with 10 ml of sterile water. Shake, let mixture stand, and administer by direct I.V. injection through Y-tube or three-way stopcock. Infuse over 5 to 10 minutes through line with running infusion of normal saline solution or dextrose 5% in water.
☞ Avoid extravasation and contact with skin, mucous membranes, and eyes.
Adverse reactions
GI: nausea, vomiting, anorexia, mouth ulcers, stomatitis
GU: renal failure, hemolytic uremic syndrome
Hematologic: anemia, leukopenia, thrombocytopenia
Respiratory: pulmonary toxicity, interstitial pneumonitis
Skin: reversible alopecia; pruritus; desquamation; phlebitis, necrosis, and sloughing with I.V. site extravasation
Other: fever
Interactions
Drug-drug. Live-virus vaccines: decreased antibody response to vaccine, increased risk of adverse reactions
Other antineoplastics: additive bone marrow depression
Vinca alkaloids: respiratory toxicity
Patient monitoring
☞ Closely monitor CBC with white cell differential and platelet count. Stay alert for evidence of blood dyscrasias.
• Assess kidney function tests. Measure fluid intake and output and evaluate fluid balance.
☞ Watch for signs and symptoms of hemolytic uremic syndrome (irritability, fatigue, pallor, and decreased urinary output).
☞ Closely monitor I.V. site and skin integrity to prevent extravasation.
☞ Assess respiratory status carefully to detect severe pulmonary problems.
Patient teaching
☞ Teach patient to recognize and immediately report signs and symptoms of hemolytic uremic syndrome, blood dyscrasias, and renal failure.
☞ Instruct patient to report cough or shortness of breath, even if it occurs several months after therapy ends.
• Advise patient to limit exposure to infections and to avoid live vaccines.
• Tell patient drug may cause hair loss. Discuss options for dealing with this problem.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.