Antimetabolite chemotherapy
Fluorouracil (5-FU)
Brand names: Efudix, Adrucil
Adult dose
Dose: Topical (Efudix) for actinic keratosis: apply OD–BD for 3–4 weeks. Systemic IV: specialist only — refer to BNF/SmPC
Route: Topical/IV
Frequency: varies
Clinical pearls
- DPD testing mandatory before systemic 5-FU/capecitabine
- Topical effective for actinic keratosis, Bowen's
Contraindications
- DPD deficiency (systemic)
- Pregnancy/breastfeeding
- Severe myelosuppression
Side effects
- Topical: erythema, erosion, photosensitivity
- Systemic: severe myelosuppression, mucositis, hand-foot syndrome, cardiotoxicity
- Severe toxicity in DPD deficiency
Interactions
- Brivudine/sorivudine (avoid — fatal toxicity)
- Warfarin (raised INR)
- Phenytoin
Monitoring
- FBC
- DPD status (systemic)
- Cardiac symptoms
Reference: BNF; NICE TA516 (DPD); MHRA; https://bnf.nice.org.uk/drugs/fluorouracil/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- Body Surface Area (Mosteller) · Anthropometry
- CRASH Score — Chemotherapy Risk Assessment Scale for High-Age · Oncogeriatrics
- CARG — Cancer and Aging Research Group Chemotherapy Toxicity Score · Oncogeriatrics
- MASCC Risk Index for Febrile Neutropenia · Febrile Neutropenia
- ECOG / WHO Performance Status · Performance Status
- Karnofsky Performance Status Scale · Performance Status
Pathways
- Acute Myeloid Leukaemia Presentation · BSH; NICE — NG146
- Tumour Lysis Syndrome · Cairo-Bishop; BSH; NICE — Best Practice
- Suspicious Pigmented Lesion — Melanoma Pathway · NICE NG14 2015 / BAD
- Cellulitis and Erysipelas · NICE NG141 2019 / CREST
- Psoriasis — Severity Assessment and Step-Up Therapy · NICE NG153 2019 / BAD
- Atopic Eczema — Assessment and Step-Up Therapy · NICE NG95 2023