Intro / Side Effects / Nausea & Vomiting

Radiation therapy directed at specific sites in the body including the gastrointestinal tract, liver, or brain can also cause nausea and vomiting. They may also arise when patients develop fluid or electrolyte imbalances such as hypercalcemia, dehydration, or retain too much fluid in the body's tissues; when a tumor is growing in the gastrointestinal tract, liver, or brain; and for other reasons.

Nausea, an unpleasant, wavelike feeling in the stomach and throat that may or may not result in vomiting, is controlled by the part of the central nervous system that governs involuntary functions. Many patients say that nausea is far more unpleasant than vomiting.

Treatment-related nausea and vomiting are classified as one of three types: anticipatory, acute, or delayed.

• Anticipatory nausea and vomiting occurs before or during chemotherapy or radiation therapy among individuals who experienced severe symptoms with previous treatment sessions. Anticipatory nausea and vomiting is triggered by specific odors, tastes, or objects that a patient associates with treatment, not by the actual presence of chemical agents in the blood.
  
  
• Acute nausea and vomiting occurs within 24 hours after cancer treatment.
  
  
• Delayed nausea and vomiting occurs more than 24 hours after cancer treatment and may continue for several days. It can cause serious problems such as dehydration and may result in hospitalization.
  
  

If nausea and vomiting are not controlled, the consequences can be severe: the patient may lose his or her appetite and become undernourished. Uncontrolled vomiting can lead to esophageal damage, broken bones, or the reopening of surgical wounds.

Fortunately, in most patients, nausea and vomiting can now be prevented or controlled. A class of drugs called antiemetics � medicines that prevent or control nausea and vomiting � are designed to accomplish this.