CYCLOPHOSPHAMIDE
(sye-kloe-foss'fa-mide)
Cytoxan, Neosar, Procytox 
Classifications: antineoplastic; alkylating agent
Pregnancy Category: C

Availability

25 mg, 50 mg tablets; 100 mg, 200 mg, 500 mg, 1 g, 2 g vials

Actions

Cell-cycle-nonspecific alkylating agent chemically related to the nitrogen mustards. Action mechanism unknown but thought to be the result of cross-linkage of DNA strands, thereby blocking synthesis of DNA, RNA, and protein. Associated with increased risk of secondary malignancies that may be detected several years after cyclophosphamide has been discontinued.

Therapeutic Effects

Has pronounced immunosuppressive activity and is a highly toxic drug; thus therapeutic effects are usually accompanied by some evidence of toxicity.

Uses

As single agent or in combination with other chemotherapeutic agents in treatment of malignant lymphoma, multiple myeloma, leukemias, mycosis fungoides (advanced disease), neuroblastoma, adenocarcinoma of ovary, carcinoma of breast, or malignant neoplasms of lung.

Unlabeled Uses

To prevent rejection in homotransplantation; to treat severe rheumatoid arthritis, multiple sclerosis, systemic lupus erythematosus, Wegener's granulomatosis, nephrotic syndrome.

Contraindications

Men and women in childbearing years; serious infections (including chickenpox, herpes zoster); live virus vaccines; myelosuppression; pregnancy (category C), lactation.

Cautious Use

History of radiation or cytotoxic drug therapy; hepatic and renal impairment, recent history of steroid therapy; bone marrow infiltration with tumor cells; history of urate calculi and gout; patients with leukopenia, thrombocytopenia.

Route & Dosage

Neoplasm
Adult: PO Initial: 1–5 mg/kg/d; Maintenance: 1–5 mg/kg q7–10d. IV Initial: 40–50 mg/kg in divided doses over 2–5 d up to 100 mg/kg; Maintenance: 10– 15 mg/kg q7–10d or 3–5 mg twice weekly
Child: PO Initial: 2–8 mg/kg or 60–250 mg/m2Maintenance: 2–5 mg/kg or 50–150 mg/m2 twice weekly. IV Initial: 2–8 mg/kg or 60–250 mg/m2

Rheumatoid Arthritis
Adult/Child: PO 1.5–2.5 mg/kg/d in combination with other agents IV 0.5–1 g/m2 monthly times 6 mo then q 2–3 mo in combination with other agents

Administration

Oral
Intravenous

PREPARE: Direct: Add 5 mL sterile water for injection or bacteriostatic water for injection (paraben-preserved only) to each 100 mg and shake gently to dissolve.  Intermittent: May be further diluted with 100–250 mL D5W, NS, D5/NS, RL, or other compatible solution.  

ADMINISTER: Direct/Intermittent: Give each 100 mg or fraction thereof over 10–15 min.  

INCOMPATIBILITIES Y-site: Amphotericin B, cholesteryl complex.

Adverse Effects (1%)

Body as a Whole: Transient dizziness, fatigue, facial flushing, diaphoresis, drug fever, anaphylaxis, secondary neoplasia. GI: Nausea, vomiting, mucositis, anorexia, hepatotoxicity, diarrhea. Hematologic: Leukopenia, neutropenia, acute myeloid leukemia, anemia, thrombophlebitis, interference with normal healing. Metabolic: Severe hyperkalemia, SIADH, hyponatremia, weight gain (but without edema) or weight loss, hyperuricemia. Respiratory: Pulmonary emboli and edema, pneumonitis, interstitial pulmonary fibrosis. Skin: Alopecia (reversible), transverse ridging of nails, pigmentation of nail beds and skin (reversible), nonspecific dermatitis, toxic epidermal necrolysis, Stevens-Johnson syndrome. Urogenital: Sterile hemorrhagic and nonhemorrhagic cystitis, bladder fibrosis, nephrotoxicity.

Diagnostic Test Interference

Cyclophosphamide suppresses positive reactions to Candida, mumps, trichophytons, and tuberculin PPD skin tests. Papanicolaou (PAP) smear may be falsely positive.

Interactions

Drug: Succinylcholine, prolonged neuromuscular blocking activity; doxorubicin may increase cardiac toxicity.

Pharmacokinetics

Absorption: Readily absorbed from GI tract. Peak: 1 h PO. Distribution: Widely distributed, including brain, breast milk; crosses placenta. Metabolism: Metabolized in liver. Elimination: Excreted in urine as active metabolites and unchanged drug. Half-Life: 4–6 h.

Nursing Implications

Assessment & Drug Effects

Patient & Family Education


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