CHEMOTHERAPY-INDUCED NAUSEA AND VOMITING (CINV)
The first thought that often comes to mind when treatment with chemotherapy is discussed is the frightening prospect of overwhelming nausea and vomiting. CINV is frequently portrayed inaccurately in the media, in movies and on television as an unavoidable and uncontrollable side effect of receiving chemotherapy.
Taking control over this symptom requires knowledge and effective communication with your healthcare team as you participate in decisions about how your CINV will be managed.
The following facts will empower you take control over CINV:
1) Not all chemotherapy drugs cause nausea and vomiting.
2) Effective drugs are available to prevent and manage nausea.
3) Drugs to manage CINV work in different ways, so if one
medication is not effective, there are many other options.
4) It is possible to predict the degree of CINV each chemotherapy drug will produce and to select medications to prevent nausea based on the specific treatment regimen.
5) Individual personal risk factors may increase the likelihood of CINV, making it even more important to design an anti-nausea strategy just for you.
6) There are non-drug strategies proven to prevent or control CINV.
Managing CINV is invaluable to your successful journey through the cancer treatment process. Although not a life-threatening side effect, CINV can lead to dehydration and nutritional problems, as well as anxiety and depression.
Nausea can affect your ability to spend time with supportive family and friends. Poorly controlled nausea or vomiting after a chemotherapy treatment may make you dread or even avoid future treatments. The American Cancer Society estimates that 70-80% of individuals receiving chemotherapy will experience some nausea.
What Is Chemotherapy-induced Nausea and Vomiting (CINV)?
Chemotherapy-induced nausea and vomiting, or CINV, is nausea and vomiting that results specifically from treatment with chemotherapy drugs. There can be other causes of nausea or vomiting that are associated with cancer or its treatment. Some examples are treatment with radiation, an obstruction in the intestine caused by a tumor, side effects of pain medications, constipation or imbalances in electrolytes (minerals and salts that keep the body chemistry in equilibrium).
Information about nausea is sent to the vomiting center in the brain from several different parts of the body including the stomach, small intestine, inner ear and the cerebral cortex – the part of the brain responsible for memory, fear and anticipation. Several different chemicals (neurotransmitters) carry information about nausea to the vomiting center, which determines the body’s response.
Nausea is defined as an unpleasant feeling in the back of your throat and stomach that may lead to vomiting. Nausea is often associated with other symptoms – a rapid heart rate, sweating, dizziness and increased saliva.
For many people, nausea is worse than vomiting.
Vomiting occurs when the muscles of your stomach and chest contract to force the contents of your stomach out through your mouth. Most people feel better after vomiting.
Dry heaves (also called retching or gagging) refers to repeated contractions of the chest and stomach muscles that do not result in vomiting. This often makes people feel worse.
Chemotherapy-induced nausea and vomiting can be divided into different categories depending primarily on time and treatment factors – when does it occur; how long does it last or how successfully can it be treated.
Anticipatory nausea and vomiting occurs before treatment and is the result of a previous negative experience with chemotherapy when nausea was poorly controlled. It is a learned or conditioned response. Anticipatory nausea and vomiting can also occur in the individual who is convinced they will be nauseated, based on everything they have heard or read about chemotherapy.
Prevention of CINV with aggressive treatment before therapy eliminates the source of anticipatory nausea and vomiting.
Acute nausea and vomiting occurs within minutes or hours after receiving a chemotherapy drug known to cause nausea. It lasts up to 24 hours.
Delayed nausea and vomiting occurs at least 24 hours after treatment and may last as long as six days. There are a few specific chemotherapy drugs associated with delayed nausea and vomiting. For those drugs, it is important to continue anti-nausea medications for several days after treatment.
Refractory nausea and vomiting is resistant to treatment. Several drug therapies in addition to non-drug strategies may be required to control this type of nausea and vomiting.
Risk Factors for Chemotherapy-Induced Nausea and Vomiting:
One of the most important things to remember is that not all chemotherapy causes nausea and vomiting. Drugs are divided into different categories, depending upon how likely they are to cause CINV if effective anti-nausea medication is not prescribed – this characteristic is called emetogenicity.
The dose level of the drug, frequency of treatment and route (intravenous or oral) is also taken into consideration in calculating risk of CINV. Some drugs will cause nausea in >90% of people who receive it without effective anti-nausea medication (high risk); other drugs will cause nausea in <10% of individuals (low or minimal risk).
A list of common chemotherapy agents and how likely they are to cause nausea and vomiting can be found at:
http://www.cancer.org/docroot/MBC/content/MBC2XNauseaandVomiting.asp
Research has determined that certain characteristics can put individuals are at greater risk for developing CINV. This includes:
Female sex
Age less than 50
History of morning sickness during pregnancy or motion (car) sickness
Anxiety
Little or no alcohol use
People who feel warm or hot during treatment or experience metallic tastes during chemotherapy may also be at greater risk for CINV.
Be knowledgeable about your personal risk factors for CINV and the risk associated with your specific chemotherapy regimen when you discuss plans for preventing or managing nausea and vomiting with your health care provider.
Prevention and Treatment of Chemotherapy-Induced Nausea and Vomiting
Being Patient Active means working with your health care team to make decisions about managing your side effects. Before you begin chemotherapy, you should discuss an anti-nausea medication plan to prevent CINV tailored specifically for you that includes:
The risk of CINV with your specific chemotherapy regimen
The impact of your personal risk factors for CINV
information about the effectiveness of anti-nausea medications you have taken in the past
How and when to take your anti-nausea medication
How long to continue taking your anti-nausea medications
side effects to expect
What to do if the anti-nausea medication is not effective
other non-drug strategies that may be helpful, including resources available at your cancer center
When to call your physician
In the past 20 years, dramatic progress has occurred in the development of drugs to prevent or treat nausea. These drugs are called anti-nausea medications or anti-emetics. Because there are several different areas of the body that can stimulate the vomiting center and different chemical transmitters carrying information about nausea, drugs in different categories work in different ways. They can often be given effectively in combination because they each combat the problem of CINV with a different approach.
The goal of CINV management is prevention.
Some important points to remember:
You will be given medication to prevent nausea before treatment.
Since the effects of the chemotherapy continue after administration, you will also be given anti-nausea drugs to take after your treatment.
You may be given more than one drug for nausea. This is because some anti-emetics work better when given together.
Anti-nausea medications are typically given on a regular ‘around the clock’ schedule. If your medication is on a regular schedule, do NOT wait until you are nauseated to take it. Remember the goal is prevention.
Ask your doctor or nurse when you should stop taking the medication so you do not stop taking it too soon.
This table is a general list of drugs currently available and their side effects.
Other non-drug strategies can be effective in managing CINV.
Consider:
Fresh air with a fan or open window
Moderate or light exercise
Music therapy
Acupressure with a seasickness band, available at your local drug store
Distraction – watching television, talking with friends
Self-hypnosis, guided imagery, muscle relaxation. A trained therapist can help you learn these techniques. Your local Wellness Community Center may be able to assist.
Nutrition can also play a part in helping to prevent nausea or in managing nausea if it occurs.
Eat lightly before your chemotherapy treatment (some people prefer to wait until after treatment to eat).
Avoid strong odors (cold or room temperature foods have less odor)
Eat small, frequent meals. If you have little appetite, limit the amount of fluids you have with meals.
Crackers, toast and gelatin are bland and should not upset your stomach.
Ice chips or small bites of popsicles may make you feel better.
Avoid spicy, fatty or fried foods and carbonated beverages.
Avoid your favorite foods when you are experiencing nausea.
Don’t force yourself to eat if you are nauseated
Ginger – some studies indicate that ginger capsules can be effective as treatment for nausea.
If you are too tired or nauseated to cook or shop, ask family, friends or neighbors to help. Your health care team may also be able to suggest other resources.
When To Call Your Physician
If your anti-nausea medication is not effective, call your doctor or nurse and ask for a different medication. Prolonged vomiting can lead to serious dehydration and other problems. Phone your health care team if:
Vomiting lasts for more than 24 hours
Vomiting occurs 3 times an hour for more than 3 hours
Vomiting looks like blood or coffee grounds
Some of the vomited material is inhaled or goes in the lungs
Unable to take 4 cups of fluid or ice chips per day
Unable to take in solid food for 2 days
Unable to take medications
Urine becomes dark yellow
Confusion, dizziness or light-headedness occurs
Additional Resources
1) National Cancer Institute
http://www.cancer.gov
2) National Center for Complementary and Alternative Medicine
http://www.nccam.nih.gov
3) American Cancer Society
http://www.cancer.org
4) Cancer Care: Professional Support for People Affected by Cancer
http://www.cancercare.org
5) Cancer Nausea
http://www.cancernausea.com