Frequently Asked Questions

Q1. Which patients are most susceptible to chemotherapy-induced nausea and vomiting?

A. Chemotherapy-induced nausea and vomiting (CINV) is a serious side effect of cancer therapy and occurs in up to 80% of patients.¹

People can vary in their susceptibility to CINV. Those affected more often include women, people under 50 years of age, people with anxiety and those with a known history of nausea and vomiting, for example, motion sickness or morning sickness during pregnancy.^2,3 Susceptibility also increases with repeated exposure to the cytotoxic drug² and patients with poor control of CINV during past chemotherapy cycles are likely to experience it in subsequent cycles.¹

Q2. What is the impact of chemotherapy-induced nausea and vomiting on patients?

A. Chemotherapy-induced nausea and vomiting (CINV) is one of the most distressing acute side effects of cancer treatment. It can have a significant impact on a patient’s quality of life and can also result in the following:¹

• Deterioration of physical and mental status.
• Serious metabolic derangements.
• Electrolyte imbalances and/or dehydration.
• Nutritional depletion and anorexia.
• Oesophageal tears.
• Fractures.
• Wound dehiscence.
• Withdrawal from potentially useful and curative antineoplastic treatment.
• Degeneration of self-care and functional ability.

It is very important to prevent and control nausea and vomiting in patients with cancer so that they can continue treatment and perform activities of daily life.⁴

Q3. What is the difference between nausea and vomiting?

A. Nausea is the subjective phenomenon of an unpleasant, wave-like sensation experienced in the back of the throat and/or the epigastrium that may culminate in vomiting (emesis).¹ Vomiting is the forceful expulsion of the contents of the stomach, duodenum, or jejunum through the oral cavity.¹

Q4. What causes chemotherapy-induced nausea and vomiting?

A. Acute and delayed CINV have different nechanisms, both involving peripheral and central nervous system (CNS) pathways.

Acute CINV - Free radicals generated by toxic chemotherapeutic agents stimulate enterochromaffin cells in the gastrointestinal tract, causing the release of serotonin.

Serotonin then binds to intestinal vagal afferent nerves via 5-HT₃ receptors, which trigger the vomiting reflex via the nucleus of the solitary tract (NTS) and chemoreceptor trigger zone (CTZ) in the CNS.

Delayed CINV - In delayed CINV, chemotherapy drugs trigger the release of substance P from neurons in the central and peripheral nervous systems, which then binds to neurokinin-1 (NK1) receptors, mainly in the NTS to induce vomiting. 5-HT₃ receptor signaling may also play a role in delayed CINV, but to a lesser extent than in acute CINV.

In both acute and delayed CINV, coordination of nausea and vomiting occurs in the vomiting center in the medulla oblongata via signals from the NTS, CTZ, or afferent vagal nerves.⁵

Q5. How is chemotherapy-induced nausea and vomiting treated?

A. There is no published NICE guidance on the treatment of chemotherapy-induced nausea and vomiting.²

Local chemotherapy antiemetic treatment protocols can vary but are often based on MASCC/ESMO antiemetic guidelines, the American Society of Clinical Oncology (ASCO) antiemetic guidelines and the National Comprehensive- Cancer Network (NCCN) antiemetic guidelines.²

The goal of each antiemetic therapy is to abolish nausea and vomiting.⁶ Blocking the receptors involved in the emesis pathway at the gastrointestinal tract, chemoreceptor trigger zone and can target CINV at multiple levels.⁷

To prevent acute nausea and vomiting following chemotherapy of high emetic risk, a three-drug regimen including single doses of a 5-HT₃ receptor antagonist, dexamethasone and aprepitant given before chemotherapy is recommended (ESMO/MASCC).⁶

Q6. Do all chemotherapy regimens cause chemotherapy-induced nausea and vomiting?

A. Chemotherapy regimens vary in the extent to which they cause nausea and vomiting (usually classed as having a minimal, low, moderate or high degree of emetogenicity).² For example, the Multinational Association for Supportive Care in Cancer (MASCC) and the European Society of Medical Oncology (ESMO) antiemetic guidelines classify the following (if given intravenously) as moderately emetogenic: cyclophosphamide (at doses of less than 1500 mg/m2), doxorubicin, epirubicin, carboplatin and as highly emetogenic: cisplatin and cyclophosphamide (at doses of 1500 mg/m2 or more).²

Nausea and vomiting symptoms may be acute (occurring within 24 hours of treatment), delayed (first occurring more than 24 hours after treatment) or anticipatory (occurring prior to subsequent doses).²

Q7. What is the non-drug treatment of nausea and vomiting?

A. Other ways to prevent nausea and vomiting are complementary therapies. They can be used alongside standard therapies, most often to prevent or reduce side effects. Some types of complementary therapy used to treat nausea and vomiting are:⁸

• Relaxation techniques – breathing exercises, meditation or tensing and relaxing the muscles.
• Hypnosis – trance-like state of deep relaxation guided by a trained specialist.
• Music therapy.
• Acupuncture and acupressure – using needles (acupuncture) or pressure (acupressure) for healing.