Live Vaccines
Contraindicated
Database
Profound immunosuppression — disseminated vaccine infection
Avoid live vaccines during and after therapy
Source: Kimi deep-research + Cla
Drug reference
Cyclophosphamide
Nitrogen-mustard alkylating agent (oxazaphosphorine) · Antineoplastic
Also known as Cytoxan, Neosar, Endoxan, Genoxal, Revimmune
START
Regimen-specific; ensure hydration ± mesna for IV pulse/high dose; e.g. lupus nephritis 500–1000 mg/m² IV monthly
TYPICAL MAX
Regimen-defined (e.g. 50 mg/kg/day transplant)
STOP IF
Haemorrhagic cystitis, severe myelosuppression/infection, anaphylaxis
WATCH
CBC, urinalysis/haematuria, sodium (SIADH), hydration, infection; fertility counselling
CDSCO approvedSchedule HATC L01AA01
KDIGO 2024 + manufacturer label
- ONSET
- 2h · metabolite activation
- PEAK
- 3h · active metabolite peak
- t½
- 6h · parent t½
- DURATION
- 2w · pulse interval (illustrative)
EXCRETION
Hepatic activation; renal parent + metabolites
route + CYP
INTERACTIONS
12 major
incl. contraindicated
PREGNANCY
Avoid — teratogenic/embryotoxic; effective contraception both sexes; avoid 1st trimester especially
FDA category + note
Top interactionssee all 12 →
- Live VaccinesContraindicatedDatabaseKimi deep-research + Cla
- AdalimumabSevereDatabaseDDInter
- BaricitinibSevereDatabaseDDInter
- CertolizumabSevereDatabaseDDInter
Available in India
50 branded formulations. Look up specific brands in the Drugs workspace.
Mechanism
Prodrug activated by hepatic CYP (mainly CYP2B6) to 4-hydroxycyclophosphamide/aldophosphamide → phosphoramide mustard, which crosslinks DNA (N7-guanine) inhibiting replication; acrolein by-product causes urothelial toxicity. Also potent immunosuppressant.
Indications
Lymphomas, leukaemias, multiple myelomaBreast, ovarian and other solid tumours (regimen-dependent)Severe autoimmune disease (e.g. lupus nephritis, ANCA vasculitis)Conditioning for haematopoietic stem-cell transplant
Dosing
- Adult
- Highly regimen-specific. Oral 1–5 mg/kg/day; IV pulses 500–1000 mg/m² (e.g. monthly in vasculitis/lupus); transplant conditioning up to 50 mg/kg/day ×4. Always with hydration ± mesna for higher doses.
- Pediatric
- Protocol-specific (oncology/rheumatology specialist).
- Renal adjustment
- Reduce dose in significant renal impairment (active metabolites accumulate); ~25% reduction CrCl <10 / dialysis.
- Hepatic adjustment
- Severe hepatic impairment may impair activation/clearance — caution, consider reduction.
- Geriatric
- Greater myelosuppression/toxicity; reduce/monitor.
- Max dose
- Regimen-defined (e.g. 50 mg/kg/day transplant); no universal ceiling
Pharmacokinetics
Onset
Counts nadir ~day 7–14
Peak effect
Active metabolite within hours
Duration
Cycle/pulse-based
Half-life
Parent ~3–12 h
Bioavailability
Oral >75%
Protein binding
Parent low; metabolites ~50%
Metabolism
Hepatic CYP2B6/3A4 activation; aldehyde dehydrogenase detox
Excretion
Renal (parent + metabolites)
Contraindications
- Severe hypersensitivity to cyclophosphamide
- Active severe infection / severe bone-marrow failure
- Urinary outflow obstruction; active haemorrhagic cystitis
Side effects
Common
Myelosuppression (dose-limiting)Nausea/vomitingAlopeciaAmenorrhoea/azoospermia
Serious
- Haemorrhagic cystitis (acrolein) — prevent with hydration/mesna
- Secondary malignancy (bladder cancer, leukaemia)
- Infertility/gonadal failure
- Cardiotoxicity (high-dose), pulmonary fibrosis
- SIADH/hyponatraemia; severe immunosuppression/opportunistic infection
- Anaphylaxis
Pregnancy & lactation
Pregnancy
Avoid — teratogenic/embryotoxic; effective contraception both sexes; avoid 1st trimester especially
Lactation
Contraindicated — excreted in milk, infant toxicity
Drug interactions
Adalimumab
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Baricitinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Certolizumab
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Cidofovir
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Cladribine
Severe
Database
Drug interaction classified as: synergy.
Source: DDInter
Clozapine
Severe
Database
Additive agranulocytosis risk
Avoid combination; monitor ANC
Source: Kimi deep-research + Cla
Deferiprone
Severe
Database
Clinical effect not specified
Source: DDInter
Fingolimod
Severe
Database
Clinical effect not specified
Source: DDInter
Golimumab
Severe
Database
Clinical effect not specified
Source: DDInter
Infliximab
Severe
Database
.
Source: DDInter
Inotersen
Severe
Database
Clinical effect not specified
Source: DDInter
Related guidelines
Ask House about Cyclophosphamide
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19