Oral fluoropyrimidine + thymidine phosphorylase inhibitor

Trifluridine with tipiracil (Specialist drug)

Brand names: Lonsurf

Trifluridine with tipiracil is an oral cytotoxic combination used under specialist supervision for refractory metastatic colorectal cancer and metastatic gastric cancer.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Trifluridine is incorporated into DNA to disrupt its function, while tipiracil inhibits thymidine phosphorylase to prevent trifluridine breakdown and maintain its levels.

Prescribing in practice

Myelosuppression, particularly neutropenia, is the principal toxicity and requires blood count checks before and during each cycle.
It is a specialist oral chemotherapy and dosing is by body surface area as detailed in the SPC.
Gastrointestinal toxicity and fatigue are common and may require dose modification.

Monitoring

Monitor full blood count before each cycle and as clinically indicated during treatment.

Counselling the patient

Report fever or signs of infection promptly during the low-blood-count period.
Handle the tablets as directed and follow safe handling advice for cytotoxic medicines.
Effective contraception is advised during and after treatment.

Evidence & guidelines

Benefit in refractory colorectal cancer is established by the RECOURSE trial and supported by NICE guidance.

Reference: NICE TA405/TA669; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways