MITOMYCIN

MITOMYCIN
(mye-toe-mye'sin)
Mutamycin, Mytozytrex
Classifications: antineoplastic; antibiotic;
Therapeutic: antineoplastic; antibiotic
Prototype: Doxorubicin
Pregnancy Category: X

Availability

5 mg, 20 mg, 40 mg injection

Action

Potent antibiotic antineoplastic compound. Effective in certain tumors unresponsive to surgery, radiation, or other chemotherapeutic agents. Action mechanism unclear but reportedly combines with DNA, thereby interfering with cellular and enzymatic RNA and protein synthesis.

Therapeutic Effect

Highly destructive to rapidly proliferating cells and slowly developing carcinomas.

Uses

In combination with other chemotherapeutic agents in palliative, adjunctive treatment of disseminated adenocarcinoma of breast, pancreas, or stomach, squamous cell carcinoma of head, neck, lung, and cervix. Not recommended to replace surgery or radiotherapy or as a single primary therapeutic agent.

Contraindications

Hypersensitivity or idiosyncrasy reaction; severe bone marrow suppression; thrombocytopenia; coagulation disorders or bleeding tendencies; pregnancy (category X), lactation.

Cautious Use

Renal impairment; myelosuppression; pulmonary disease or respiratory insufficiency.

Route & Dosage

Cancer
Adult/Child: IV 10–20 mg/m²/d as a single dose q6–8wk, additional doses based on hematologic response

Renal Impairment
Cl_cr <10 mL/min: use 75% of dose

Administration

Intravenous

Note: Verify correct IV concentration and rate of infusion/injection for administration to children with physician.

PREPARE: Direct: Dilute each 5 mg with 10 mL sterile water for injection. Shake to dissolve. If product does not clear immediately, allow to stand at room temperature until solution is obtained. Reconstituted solution is purple. IV Infusion: May be further diluted to concentrations of 20–40 mcg in D5W, NS, or RL.

ADMINISTER: Direct: Give reconstituted solution over 5–10 min or longer. IV Infusion: ??Give over 10 min or longer as determined by total volume of solution. ??D5W IV solutions must be infused within 3 h of preparation (see STORAGE).??Monitor IV site closely. Avoid extravasation to prevent extreme tissue reaction (cellulitis) to the toxic drug.

INCOMPATIBILITIES Solution/additive: dextrose-containing solutions, bleomycin. Y-site: Aztreonam, cefepime, etoposide, filgrastim, gemcitabine, piperacillin/tazobactam, sargramostim, topotecan, vinorelbine.

Store drug reconstituted with sterile water for injection (0.5 mg/mL) for 14 d refrigerated or 7 d at room temperature.
Drug diluted in D5W (20–40 mcg/mL) is stable at room temperature for 3 h.

Adverse Effects (≥1%)

CNS: Paresthesias. GI: Stomatitis, nausea, vomiting, anorexia, hematemesis, diarrhea. Hematologic: Bone marrow toxicity (thrombocytopenia, leukopenia occurring 4–8 wk after treatment onset), thrombophlebitis, anemia. Respiratory: Acute bronchospasm, hemoptysis, dyspnea, nonproductive cough, pneumonia, interstitial pneumonitis. Skin: Desquamation; induration, pain, necrosis, cellulitis at injection site; reversible alopecia, purple discoloration of nail beds. Body as a Whole: Pain, headache, fatigue, edema. Urogenital: Hemolytic uremic syndrome, renal toxicity.

Pharmacokinetics

Metabolism: Metabolized rapidly in liver. Elimination: In urine. Half-Life: 23–78 min.

Nursing Implications

Assessment & Drug Effects

Lab tests: Perform WBC with differential, platelet count, PT, INR, aPTT, Hgb, Hct, and serum creatinine frequently during and for at least 7 wk after treatment.
Do not administer if serum creatinine is >1.7 mg/dL or if platelet count falls below 150,000/mm³ and WBC is down to 4000/mm³ or if prothrombin or bleeding times are prolonged.
Monitor I&O ratio and pattern. Report any sign of impaired kidney function: Change in ratio, dysuria, hematuria, oliguria, frequency, urgency. Keep patient well hydrated (at least 2000–2500 mL orally daily if tolerated). Drug is nephrotoxic.
Observe closely for signs of infection. Monitor body temperature frequently.
Inspect oral cavity daily for signs of stomatitis or superinfection (see Appendix F).

Patient & Family Education

Report respiratory distress to physician immediately.
Report signs of common cold to physician immediately.
Understand that hair loss is reversible after cessation of treatment.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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