Causes of Nausea and Vomiting

Nausea and vomiting in the person with cancer can be caused by a number of different factors:

• chemotherapy
• radiation therapy
• the cancer itself
• certain medicines
• bowel obstruction, anxiety, infections, and other diseases or illnesses

The information in this guideline is about the nausea and vomiting caused by chemotherapy (chemotherapy-related nausea and vomiting) or radiation therapy (radiation therapy-related nausea and vomiting). Patients who are going to be treated for cancer should discuss what treatments are available to prevent nausea and vomiting with their health care team before they have nausea and vomiting.

How Does Nausea and Vomiting Occur?

It is thought that vomiting is controlled by the vomiting center located in the brain. Less is known about how nausea occurs. When chemotherapy is given, a message is sent to the brain either through 1 of 2 ways:

• stimulation of a specific area of the brain
• stimulation of certain parts of the esophagus, stomach, small intestine, and large intestine

Chemotherapy medicines are thought to cause vomiting through both mechanisms.

Factors Affecting Nausea and Vomiting

In patients receiving chemotherapy, nausea and vomiting is influenced by a number of factors, including:

• types of chemotherapy agents used
  
• dose of the drugs (high doses of chemotherapy are more likely to cause nausea and vomiting)
  
• when and how often the drug is given; for example, if a chemotherapy drug that causes nausea and vomiting is given in frequent intervals, there is less time for the person to recover from the nausea and vomiting before the next treatment is given
  
• how the drugs are given; for example, a chemotherapy drug that is given into the vein (intravenous, or by IV) may cause nausea and vomiting to occur faster than a drug that is given by mouth, because the drug given by IV is absorbed more quickly
  
• individual differences; for example, not every person has the same reaction to a particular dose or type of chemotherapy

INTRODUCTION

TYPES OF NAUSEA AND VOMITING

For more information on these treatment guidelines, or on cancer in general, call the NCCN at 1-888-909-NCCN or the American Cancer Society at 1-800-ACS-2345. Or you can visit these organizations’ web sites at www.cancer.org (ACS) and www.nccn.org (NCCN).

© 2007 by the National Comprehensive Cancer Network (NCCN) and the American Cancer Society (ACS). All rights reserved. The information herein may not be reproduced in any form for commercial purposes or downloaded and stored in any information-retrieval system without the express written permission of the NCCN and the ACS. Single copies of each page may be printed out for personal, noncommercial use only.