Skip to content
My WebMD Sign In, Sign Up

Cancer Health Center

Font Size

Nausea and Vomiting (PDQ®): Supportive care - Health Professional Information [NCI] - Anticipatory Nausea and Vomiting (Emesis)

Prevalence

The prevalence of anticipatory nausea and vomiting (emesis) (ANV) has varied, owing to changing definitions and assessment methods.[1] However, anticipatory nausea appears to occur in approximately 29% of patients receiving chemotherapy (about one of three patients), while anticipatory vomiting appears to occur in 11% of patients (about one of ten patients).[2] With the introduction of new pharmacologic agents (5-HT3 receptor antagonists), it was anticipated that the prevalence of ANV might decline; however, studies have shown mixed results. One study found a lower incidence of ANV,[3] and three studies found comparable incidence rates.[2,4,5] It appears that the 5-HT3 agents reduce postchemotherapy vomiting but not postchemotherapy nausea,[2,5] and the resulting impact on ANV is unclear.

Recommended Related to Cancer

About This PDQ Summary

Purpose of This Summary This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about liver (hepatocellular) cancer screening. It is intended as a resource to inform and assist clinicians who care for cancer patients. It does not provide formal guidelines or recommendations for making health care decisions. Reviewers and Updates This summary is reviewed regularly and updated as necessary by the PDQ Screening and...

Read the About This PDQ Summary article > >

Classical Conditioning

Although other theoretical mechanisms have been proposed,[6] ANV appears to be best explained by classical conditioning (also known as Pavlovian or respondent conditioning).[7] In classical conditioning, a previously neutral stimulus (e.g., smells of the chemotherapy environment) elicits a conditioned response (e.g., ANV) after a number of prior pairings or learning trials. In cancer chemotherapy, the first few chemotherapy infusions are the learning trials. The chemotherapy drugs are the unconditioned stimuli that elicit postchemotherapy nausea and vomiting (N&V) (in some patients). The drugs are paired with a variety of other neutral, environmental stimuli (e.g., smells of the setting, oncology nurse, chemotherapy room). These previously neutral stimuli then become conditioned stimuli and elicit ANV in future chemotherapy cycles. ANV is not an indication of psychopathology but is rather a learned response that, in other life situations (e.g., food poisoning), results in adaptive avoidance. A variety of correlational studies provide empirical support for classical conditioning. For example, the prevalence of ANV prior to any chemotherapy is very rare, and few patients ever experience ANV without prior postchemotherapy nausea.[8] Also, most studies have found (1) a higher probability of ANV with increasing numbers of chemotherapy infusions and (2) the intensity of ANV increasing as patients get closer to the actual time of their infusion.[9] In one experimental study, it was shown that a novel beverage could become a conditioned stimulus to nausea when paired with several chemotherapy treatments.[10]

Variables Correlated with ANV

Many variables have been investigated as potential factors that correlate with the incidence of ANV in hopes of developing a list of risk factors. There is currently no agreement on which factors predict ANV. A patient with fewer than three of the first eight characteristics listed below, however, is unlikely to develop ANV, and screening following the first chemotherapy infusion could identify those patients at increased risk.[11]

Variables Found to Correlate With ANV

  1. Age younger than 50 years.
  2. N&V after last chemotherapy session.
  3. Posttreatment nausea described as moderate, severe, or intolerable.
  4. Posttreatment vomiting described as moderate, severe, or intolerable.
  5. Feeling warm or hot all over after last chemotherapy session.
  6. Susceptibility to motion sickness.
  7. Sweating after last chemotherapy session.
  8. Generalized weakness after last chemotherapy session.
  9. Female gender.
  10. High-state anxiety (anxiety reactive to specific situations).[12,13]
  11. Greater reactivity of the autonomic nervous system and slower reaction time.[14]
  12. Patient expectations of chemotherapy-related nausea before beginning treatment.[15,16]
  13. Percentage of infusions of chemotherapy followed by nausea.[17]
  14. Postchemotherapy dizziness.
  15. Lightheadedness.
  16. Longer latency of onset of posttreatment N&V.[18]
  17. Emetogenic potential of various chemotherapeutic agents. Patients receiving drugs with a moderate to severe potential for posttreatment N&V are more likely to develop ANV.[12]
  18. Morning sickness during pregnancy.
1|2

WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
Next Article:

Today on WebMD

Building a Support System
Blog
cancer fighting foods
SLIDESHOW
 
precancerous lesions slideshow
SLIDESHOW
quit smoking tips
SLIDESHOW
 
Jennifer Goodman Linn self-portrait
Blog
what is your cancer risk
HEALTH CHECK
 
colorectal cancer treatment advances
Video
breast cancer overview slideshow
SLIDESHOW
 
prostate cancer overview
SLIDESHOW
lung cancer overview slideshow
SLIDESHOW
 
ovarian cancer overview slideshow
SLIDESHOW
Actor Michael Douglas
Article