Brivudine
Contraindicated
Database
Irreversible DPD inhibition → fatal 5-FU accumulation
Absolute avoidance; ≥4-week interval
Source: Kimi deep-research + Cla
Drug reference
5-Fluorouracil
Antimetabolite (fluoropyrimidine) · Antineoplastic
Also known as Fluorouracil, 5-FU, Adrucil, Efudex, Carac
START
Regimen-specific (e.g. FOLFOX bolus 400 mg/m² + 2400 mg/m² 46-h infusion with leucovorin); consider DPYD genotyping
TYPICAL MAX
Regimen-defined (per m²)
STOP IF
DPD deficiency, severe diarrhoea/mucositis, cardiac ischaemia, hyperammonaemic encephalopathy
WATCH
CBC, mucositis/diarrhoea grading, cardiac symptoms during infusion, DPYD status, hydration
CDSCO approvedSchedule HJan AushadhiNPPA price-controlledATC L01BC02
KDIGO 2024 + manufacturer label
- ONSET
- 3min · absorption onset
- PEAK
- 18min · plasma Cmax (rapid)
- t½
- 15min · plasma t½ (~15 min)
- DURATION
- 1.9d · infusional schedule
EXCRETION
DPD catabolism (CO2 expired); minor renal
route + CYP
INTERACTIONS
4 major
incl. contraindicated
PREGNANCY
Avoid — teratogenic/embryotoxic; effective contraception both sexes during and after
FDA category + note
Top interactionssee all 6 →
- BrivudineContraindicatedDatabaseKimi deep-research + Cla
- Live VaccinesContraindicatedDatabaseKimi deep-research + Cla
- PhenytoinSevereDatabaseKimi deep-research + Cla
- WarfarinSevereDatabaseKimi deep-research + Cla
Available in India
24 branded formulations. Look up specific brands in the Drugs workspace.
Jan Aushadhi — generic available at GoI pharmacies
Mechanism
As FdUMP irreversibly inhibits thymidylate synthase (with folate cofactor), depleting dTMP and blocking DNA synthesis; FUTP incorporation into RNA disrupts processing — S-phase cytotoxicity. Catabolised by DPD.
Indications
Colorectal, gastric, pancreatic, breast and head-and-neck cancers (regimen-dependent)Topical actinic keratosis / superficial basal cell carcinoma (topical formulation)
Dosing
- Adult
- Regimen-specific IV: e.g. bolus 400 mg/m² + infusion 2400 mg/m² over 46 h (FOLFOX/FOLFIRI) with leucovorin; varies widely. Topical 5% for actinic keratosis.
- Pediatric
- Not established.
- Renal adjustment
- No formal IV adjustment, but caution in significant impairment; monitor toxicity.
- Hepatic adjustment
- Bilirubin >5 mg/dL: avoid/withhold; caution in hepatic dysfunction.
- Geriatric
- Greater toxicity (diarrhoea, mucositis, myelosuppression); monitor/reduce.
- Max dose
- Regimen-defined (per m²)
Pharmacokinetics
Onset
Counts nadir ~day 9–14
Peak effect
Plasma minutes (rapid)
Duration
Infusion/cycle-based
Half-life
~8–20 min (parent); active anabolites longer intracellularly
Bioavailability
IV (oral erratic — use capecitabine)
Protein binding
Low (~10%)
Metabolism
~80% catabolised by DPD (liver) to inactive metabolites
Excretion
Mainly metabolic (CO2 expired); ~small renal unchanged
Contraindications
- Complete dihydropyrimidine dehydrogenase (DPD) deficiency
- Severe bone-marrow suppression / serious infection
- Poor nutritional state / severe debilitation
- Pregnancy; severe hypersensitivity to fluorouracil
Side effects
Common
MyelosuppressionMucositis/stomatitis, diarrhoeaNausea/vomitingHand–foot syndrome (infusional)Alopecia, photosensitivity
Serious
- Severe diarrhoea/dehydration, neutropenic sepsis
- Cardiotoxicity (coronary vasospasm, ischaemia, arrhythmia)
- Severe mucositis
- Hyperammonaemic encephalopathy
- DPD-deficiency life-threatening toxicity; leukoencephalopathy
Pregnancy & lactation
Pregnancy
Avoid — teratogenic/embryotoxic; effective contraception both sexes during and after
Lactation
Contraindicated — discontinue breastfeeding
Drug interactions
Live Vaccines
Contraindicated
Database
Immunosuppression — disseminated infection
Avoid live vaccines
Source: Kimi deep-research + Cla
Phenytoin
Severe
Database
Raised phenytoin levels → toxicity
Monitor phenytoin levels
Source: Kimi deep-research + Cla
Warfarin
Severe
Database
Potentiated anticoagulation → bleeding
Frequent INR; consider LMWH
Source: Kimi deep-research + Cla
Oxaliplatin
Moderate
Textbook
Enhanced anticancer efficacy.
Used in combination regimens.
Source: KDT 7e · p862
Leucovorin
Moderate
Database
Potentiates thymidylate synthase inhibition (and toxicity)
Use only in defined regimens; monitor mucositis/diarrhoea
Source: Kimi deep-research + Cla
Related guidelines
Ask House about 5-Fluorouracil
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: KD Tripathi 7e, Goodman & Gilman 14e, Harrison 22e·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19