A strong four-drug infusion used when someone is fit enough to tolerate it. It's effective but demanding — expect low blood counts (often with a white-cell booster), diarrhea, and nerve tingling.
5-FU + leucovorin + irinotecan + oxaliplatin every 2 weeks — an intensive four-drug regimen. It combines irinotecan's diarrhea, oxaliplatin's cold-triggered/cumulative neuropathy, and significant blood-count drops; growth-factor support is common.
Get help straight away — this is true on any regimen, on any day.
A temperature of 100.4°F (38°C) or higher during treatment can mean a
serious infection while your blood counts are low. Call your team or go to the ER — do not
wait it out.
Also urgent: trouble breathing or chest pain · swelling of the face, lips or throat ·
new confusion or fainting · shaking chills · not being able to keep fluids down.
This is standing guidance shown to everyone. Nothing on this page is based on anything
about you, and nobody is monitoring you.
Timed to the cycle
Day 1 is the day of your infusion. These are the effects a retrievable
document ties to a day range for this regimen — not a prediction about you.
Diarrhea
Typically around days 5–11
Both an early (during-infusion) and a late (~day 5) diarrhea can occur. Start loperamide at the first loose stool and hydrate; report escalation promptly.
Call your team urgently: More than 6 stools above normal, diarrhea with fever, or any with lightheadedness — call urgently.
severe in 12.7% · Timing from the manufacturer’s prescribing information · from Irinotecan, Fluorouracil
Neutropenia
Typically around days 8–27
A drop in infection-fighting white cells — the most common serious effect. A white-cell booster (G-CSF) is often added to reduce risk.
Call your team urgently: A temperature of 100.4°F (38.0°C) or higher — an emergency.
severe in 45.7% · Timing from a drug-monograph reference · from Irinotecan, Oxaliplatin, Fluorouracil
Febrile neutropenia
Typically around days 8–27
Fever occurring while white cells are low — a medical emergency needing immediate antibiotics.
Call your team urgently: Fever with feeling unwell — go to the ER and say you're on chemotherapy.
severe in 5.4% · Timing from a drug-monograph reference · from Irinotecan, Oxaliplatin, Fluorouracil
Thrombocytopenia
Typically around days 8–27
A drop in platelets (which help blood clot). Watch for easy bruising or bleeding.
Call your team: Bleeding that won't stop, or black/tarry stools.
severe in 9.1% · Timing from a drug-monograph reference · from Oxaliplatin
Not tied to a cycle day
These build with the number of doses, or are measured from when treatment started, so a cycle day would be the wrong shape for them. Each keeps the timing its own source states.
Peripheral neuropathy (cumulative)
acute cold-triggered + cumulative over cycles
Cold-triggered tingling early on, and a cumulative numbness/tingling that builds with cycles. Avoid cold in the first days after each cycle; your team tracks it.
Call your team: Numbness that makes it hard to button clothes, walk, or feel the floor.
severe in 9% · from Oxaliplatin
Fatigue
Significant tiredness is common with this intensive regimen. Pace activities, rest, and accept help.
severe in 23.6% · from Irinotecan, Oxaliplatin, Fluorouracil
S2. Irinotecan (Camptosar) FDA prescribing information — FDA label
S3. Oxaliplatin (Eloxatin) FDA prescribing information — FDA label
Timing windows on this page rest on:
BC Cancer Drug Manual — irinotecan — “350 mg/m2 q3wk: nadir 8-9 days; 125 mg/m2 weekly: nadir 15-27 days” source
Camptosar (irinotecan) FDA prescribing information — “the median time to the onset of late diarrhea was 5 days with 3-week dosing and 11 days with weekly dosing” source
A window appears here only where a retrievable document ties it to a drug in
this regimen. Where nothing could be found, the window was removed rather than estimated —
so a missing time is an honest gap, not an oversight.