Nausea and Vomiting During Chemotherapy: Why You Shouldn’t Put Up With It

Nausea and vomiting during chemotherapy are common, but in most cases they can be managed. The risk of vomiting is known in advance for every regimen, and prevention is chosen to match it: usually a combination of several drugs started before the chemotherapy is given. If you still feel sick, that’s a reason to tell your doctor and adjust the plan — not to put up with it.

Types of nausea during chemotherapy

Doctors distinguish several types of nausea and vomiting, because they are prevented and treated differently.

A word about delayed nausea in particular. Patients often ask me: “I was fine on the day of the drip, but on day three I felt awful — is that normal?” Yes, it happens, and that’s exactly why anti-sickness medicines are sometimes prescribed not only on the day of treatment but for several days afterwards.

Anticipatory nausea is more common in people whose nausea was poorly controlled in earlier cycles. That’s another reason not to put up with it from the very first cycle.

What determines the risk: how emetogenic the regimen is

Emetogenicity is a drug’s ability to cause vomiting. It is measured by the proportion of patients who would vomit without prevention. RUSSCO guidelines define four levels:

Highly emetogenic treatments include, for example, cisplatin and the AC regimen (an anthracycline + cyclophosphamide) in women with breast cancer. If a regimen includes several drugs, NCCN sets the level according to the most emetogenic one.

These percentages are the risk without prevention. With the right medicines, the real picture for most patients is quite different.

Besides the regimen, personal risk factors are taken into account. In RUSSCO guidelines these are female sex, age under 55, nausea and vomiting in the past (including during pregnancy), fear of treatment, and no history of heavy drinking. Tell your doctor if any of these apply to you: prevention may be stepped up from the first cycle.

How nausea is prevented: what the guidelines say

Prevention is given before chemotherapy and on a schedule, not “if you feel sick”. NCCN states plainly that nausea and vomiting are much harder to stop once they have started.

Modern regimens use several classes of drugs (the doses and specific drugs are chosen by your doctor):

• 5-HT3 receptor antagonists — one of the main classes; they work best when taken on schedule before and during chemotherapy;
• NK1 receptor antagonists — especially useful against delayed nausea;
• dexamethasone — a steroid that is usually combined with other anti-sickness medicines;
• olanzapine — helps especially in combination with other anti-sickness medicines; it can cause drowsiness;
• for anxiety-related and anticipatory nausea, benzodiazepines are sometimes added.

How they are combined depending on the risk:

• High risk. In the 2023 update of the MASCC/ESMO guidelines, olanzapine became a standard part of a four-drug regimen: NK1 antagonist + 5-HT3 antagonist + dexamethasone + olanzapine. After the AC regimen, according to these guidelines, dexamethasone is not needed beyond day one. RUSSCO also describes a combination of 2–4 drugs per cycle for at least 3 days.
• Moderate risk. The basis is a 5-HT3 antagonist and dexamethasone. With additional risk factors, a three-drug regimen with olanzapine or an NK1 antagonist is possible (RUSSCO).
• Low risk. A single drug, or monitoring and treatment if nausea appears.
• Minimal risk. Without risk factors, prevention is usually not needed.

NCCN states that after highly emetogenic chemotherapy prevention continues for at least 3 days, and after moderately emetogenic chemotherapy for at least 2 days. Your doctor may prescribe differently — follow their plan.

A couple of practical details from the American Cancer Society. Dexamethasone is best taken with food and in the first half of the day: this means less stomach irritation and fewer sleep problems. NK1 antagonists are better at preventing nausea than treating it once it has started — which is why they’re given in advance. Some drugs are prescribed “as needed” — at the first signs of nausea; ask which of yours are like this.

If prevention hasn’t worked. Nausea that occurs despite the right regimen is called breakthrough nausea. The American Cancer Society describes the options like this: the doctor can switch the drug, add another one or change the way it’s given. If nausea recurs with every cycle, the prevention plan is reviewed before the next treatment. For that your doctor needs feedback from you: which days were bad, how many times you vomited, whether you could keep fluids down.

If your discharge instructions don’t make it clear what to take and when, take a photo of the plan and check with the nurse or doctor before you go home. I’ve written separately about how a course of chemotherapy works.

What you can do yourself: non-drug measures

Non-drug measures don’t replace tablets, but they help. Here is what NCCN and the American Cancer Society suggest:

• eat little and often, and don’t let your stomach get empty;
• sip fluids throughout the day; cool, clear drinks are usually easier to tolerate;
• choose food that is cool or at room temperature — it smells less;
• avoid strong food and drink smells, and air the room;
• after vomiting, wait until it stops, rinse your mouth and start with small sips of fluid.

There is a separate article on food during this time: what to eat during chemotherapy.

Relaxation techniques — breathing exercises, progressive muscle relaxation, meditation — help reduce nausea, according to the American Cancer Society. For anticipatory nausea, RUSSCO mentions psychotherapy, systematic desensitisation and other non-drug methods.

Ginger and acupressure. There is research on ginger, but, as the American Cancer Society notes, it’s hard to tell from it how much is needed and in what form, and supplements can have side effects. Acupressure helps some people. What I usually say is this: you can try them, but not instead of anti-sickness medicines — and check any supplements with your doctor first.

Why you shouldn’t put up with it

Sometimes patients don’t mention nausea because they’re afraid treatment will be stopped, or they think it’s a “normal price to pay”. That’s a mistake, for several reasons.

Vomiting leads to dehydration and weight loss. Uncontrolled nausea in the first cycle raises the risk of anticipatory nausea in later ones. And most importantly — if the current plan isn’t working, it can almost always be strengthened or changed. NCCN advises reporting side effects rather than trying to tough them out.

If nausea stops you eating and drinking and your anti-sickness medicines aren’t helping, that’s not something to “put up with until the next cycle” — it’s a reason to call your care team today.

When to call your doctor urgently

Contact your oncologist or your clinic’s out-of-hours line if:

• you can’t keep fluids down;
• vomiting has lasted 24 hours or longer;
• you vomit 4–5 times in 24 hours (the NCCN threshold);
• you can’t take your prescribed medicines, or the anti-sickness medicines aren’t working;
• your urine has become dark, or you’re passing noticeably less;
• your abdomen is bloated, painful or swollen before episodes of vomiting;
• you suspect vomit may have got into your airways.

Call your local emergency number (911 in the US, 999 in the UK, 112 in the EU) if:

• there is blood in your vomit, or it looks like coffee grounds;
• you develop marked weakness, dizziness or confusion.

If you develop a temperature along with nausea, read my article on fever during chemotherapy: it is a separate emergency.

Questions to ask your oncologist

• What is the risk of nausea with my regimen — high, moderate or low?
• Which anti-sickness medicines have I been prescribed, and on which days and at what times should I take them?
• What should I take if nausea starts anyway?
• At what point should I call you, and on which number — including at night and at weekends?
• Can my prevention plan be changed if it didn’t work this cycle?

If nausea comes back cycle after cycle and the plan isn’t being changed, I’ll look at your situation in a consultation during treatment and suggest what to discuss with your doctor.

Sources

1. Практические рекомендации по профилактике и лечению тошноты и рвоты у онкологических больных (Practice guidelines for the prevention and treatment of nausea and vomiting in cancer patients) — Russian Society of Clinical Oncology (RUSSCO), 2023 (revised 2024)
2. 2023 updated MASCC/ESMO consensus recommendations: prevention of nausea and vomiting following high-emetic-risk antineoplastic agents — MASCC/ESMO, Supportive Care in Cancer, 2023
3. 2023 MASCC and ESMO guideline update for the prevention of chemotherapy- and radiotherapy-induced nausea and vomiting — ESMO, ESMO Open, 2024
4. NCCN Guidelines for Patients: Nausea and Vomiting — NCCN, 2022
5. Managing Nausea and Vomiting at Home — American Cancer Society
6. What Are Nausea and Vomiting? — American Cancer Society