What CAPOX is
CAPOX (also called XELOX, after the brand Xeloda) combines two drugs: oxaliplatin, given into a vein in the day unit, and capecitabine, a chemotherapy in tablet form that the body converts into 5-fluorouracil. It is as effective as FOLFOX both after surgery and in metastatic disease, with the advantage of needing no infusion pump or central line, and the disadvantage of more hand-foot syndrome and of placing the responsibility for taking the medication correctly on you.
What the cycle looks like
Each cycle lasts 21 days:
- Day 1: intravenous oxaliplatin (about 2 hours) in the day unit.
- Days 1 to 14: capecitabine at home, morning and evening.
- Days 15 to 21: rest, no tablets.
In adjuvant treatment (after surgery) it is 4 cycles (3 months) or 8 cycles (6 months) depending on risk; in metastatic disease, for as long as it works and is tolerated, often with bevacizumab.
How to take capecitabine
- Two doses a day, about 12 hours apart (for example, 8 am and 8 pm).
- Within 30 minutes after a meal (breakfast and dinner). With water. Not on an empty stomach.
- Swallow whole: do not crush, split or chew. If you cannot swallow them, tell your team; there are alternatives, but do not improvise.
- The dose usually combines 500 mg and 150 mg tablets. Use a pill organiser or a tick sheet: it is easy to get wrong.
- If you miss a dose: skip it and take the next one at the usual time. Never double the dose.
- If you vomit after taking it, do not repeat the dose; note it down and mention it.
- Wash your hands after handling the tablets; people living with you should not touch them without gloves if they are broken or damaged.
Before starting: the DPD test
Capecitabine is cleared by the enzyme DPD. A small percentage of people are deficient, and in them the drug can be very toxic. The European Medicines Agency recommends testing the DPYD gene before the first dose; in Spain this is routine practice. If nobody has mentioned it, ask.
Important interactions
- Oral anticoagulants (acenocoumarol/Sintrom, warfarin): capecitabine increases their effect and the risk of bleeding. The INR must be checked far more often, or the anticoagulant changed. This is the most dangerous interaction.
- Allopurinol (for uric acid): may reduce the effectiveness of capecitabine; it is usually replaced.
- Phenytoin (anti-epileptic): its levels may rise; monitoring is needed.
- Antacids containing aluminium or magnesium: separate them from capecitabine by at least 2 hours.
- Folic acid and vitamin supplements containing folate: may increase toxicity; check first.
Always bring the full list of what you take to your appointment, including herbal products.
Side effects
| Effect | What you will notice | What to do |
|---|---|---|
| Hand-foot syndrome | Redness, tingling, dryness and pain on palms and soles; at higher grades, blisters and cracks | Urea-based moisturiser several times a day from the start, avoid friction and heat, comfortable shoes. If it hurts or limits your activities, report it: treatment is paused or the dose lowered, and it recovers. |
| Diarrhoea | Loose stools | Loperamide as prescribed, fluids. With 4 or more stools above your usual per day, night-time diarrhoea or blood: stop capecitabine and call. |
| Mouth sores | Ulcers in the mouth | Alcohol-free mouthwash, soft toothbrush. If they stop you eating, report it. |
| Nausea | Mainly in the first days after oxaliplatin | Scheduled anti-sickness drugs. |
| Cold-triggered neuropathy (oxaliplatin) | Tingling with cold in the first days; cumulative over cycles | Avoid cold; report as soon as it becomes persistent. See the neuropathy guide. |
| Low white cells | Not noticeable unless there is fever | Fever ≥ 38 °C: emergency department. |
| Chest pain | Rare: coronary spasm caused by capecitabine | Stop taking it and go to the emergency department. |
When to stop taking it and call
Stop the tablets and contact your team (or the emergency department) if you have: fever of 38 °C or more; severe diarrhoea; vomiting that prevents you drinking or taking medication; mouth sores that stop you eating; pain or blisters on hands or feet that stop you walking or holding objects; chest pain. Do not "hold on until the next cycle": stopping for a few days in time prevents serious toxicity and does not reduce effectiveness.
What to ask at your appointment
- Have I had the DPD test?
- How many tablets of each strength do I take at each dose? Can you give me a written sheet?
- Do any of my regular medicines interact (anticoagulants, allopurinol, antacids)?
- At how many stools, or what grade of hand-foot syndrome, should I stop and call? Which number?
- CAPOX or FOLFOX? Why in my case, and how many cycles?
