Cyclophosphamide
CYTOXAN
What it isAlkylating prodrug used for malignancy, vasculitis, and organ-threatening autoimmune disease.
Why this oneIts unusual reach spans curative chemotherapy and rapid control of severe autoimmune disease.
What limits it⚑ Acrolein causes hemorrhagic cystitis; urotoxic regimens require mesna and hydration. Cumulative exposure risks infertility and bladder cancer.
FDA-approved for
- cancer (1959)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Malignant diseases (initial & maintenance) | Adults & pediatrics | 1–5 mg/kg QD | ||
| Minimal change nephrotic syndrome | Pediatrics | 2 mg/kg QD × 8–12 wk | cumulative 168 mg/kg |
Renal Monitor for toxicity in moderate–severe renal impairment (CrCl 10–24 mL/min); increased plasma levels/toxicity expected
Hepatic Severe hepatic impairment: reduced conversion to active metabolite, potentially reduced efficacy
Treatment beyond 90 days increases probability of sterility in males
Instructions
- Take in the morning with adequate fluids to force diuresis (reduce urinary tract toxicity)
- Swallow whole; do not chew or crush
- Cytotoxic drug — avoid exposure to broken tablets
Contraindications
- Urinary outflow obstruction
Cautions
- Myelosuppression, immunosuppression, bone marrow failure and serious/fatal infections
- Hemorrhagic cystitis and urinary/renal toxicity
- Cardiotoxicity (myocarditis, arrhythmias, CHF)
- Pulmonary toxicity (pneumonitis, fibrosis)
- Secondary malignancies
- Veno-occlusive liver disease
- Embryo-fetal toxicity
- Impaired fertility
- Hyponatremia / SIADH-like syndrome
Adverse reactions
- Neutropenia, febrile neutropenia
- Fever
- Alopecia
- Nausea, vomiting, diarrhea
Pregnancy Can cause fetal harm (malformations, miscarriage, growth retardation); use effective contraception
Lactation Do not breastfeed during treatment and for 1 week after last dose
NO BOXED WARNINGS
Principal riskHemorrhagic cystitis; mesna and hydration are mandatory
Cost, est. cash$50–$10,000/month or cycle
Generic entry1982
Classes and tags
Clinical profile
Legacy pregnancy categoryD
Defining liabilityMyelosuppression, hemorrhagic cystitis, infertility, malignancy and organ toxicity.
Active metabolites
Mechanism of action: Cyclophosphamide ballicule
Open Cyclophosphamide in the interactive console ↗
Memory aids: mascots and interaction avatars
DNA alkylator → phosphoramide mustard
acrolein → hemorrhagic cystitis (prevent with mesna)
