What causes nausea in breast cancer patients?
The drugs used to destroy cancer cells are also toxic to healthy cells in the digestive tract. Chemo also causes chemicals to be released in the digestive tract that eventually stimulate the portion of the brain that controls vomiting and nausea.
Other causes of nausea during breast cancer treatment include radiation therapy and other medications. Sometimes the cancer itself will make the patient nauseated, and cancer-related fatigue can also cause nausea.
In addition, constipation -- a common side effect of breast cancer treatment -- can contribute to nausea by slowing down digestion so that food moves sluggishly through the body. To reduce constipation, it helps to take in ample dietary fiber and use laxatives if necessary.
Prevention strategies for nausea
The first step to preventing nausea, says Redwing Keyssar, palliative care program coordinator for Seniors-at-Home, a program of Jewish Family and Children's Services in the San Francisco Bay Area, is to take the threat of nausea seriously. If the doctor says that a chemotherapy drug is likely to cause nausea, listen to the warning and take preventive steps.
It's common for patients to wait until they feel really nauseated before starting to treat it, says Keyssar, b ut that approach often backfires. "Once the place in the brain that controls vomiting is activated, it's hard to stop," she says.
If you or the person in your care isn't keen on taking medication for symptoms that haven't appeared yet, remember that nausea is one of the reasons some patients don't want to continue cancer treatment. That's one reason doctors make it a priority to try to control nausea before it starts.
Certain chemotherapy drugs used for breast cancer are more likely to cause nausea and vomiting than others. These include:
- Epirubicin (Ellence)
- Doxorubicin (Adriamycin)
- Docetaxel (Taxotere)
- Carmustine (BiCNU)
- Cyclophosphamide (Cytoxan)
- Methotrexate (Mexate)
A chemotherapy regimen that includes one of these drugs is more like to trigger nausea and vomiting after treatment. Many other chemotherapy drugs also cause nausea when given at high doses, so find out what drug is being administered and whether the dosage is high or low.
Most people undergoing chemotherapy are prescribed drugs to prevent nausea and vomiting. Known as antiemetics, these drugs work by regulating the chemicals in the brain that control nausea. Some are given orally and some intravenously, and they're used alone or in combination.
Doctors usually begin treatment with antiemetics before chemotherapy begins, and the treatment helps to keep nausea at bay for several hours or days. Even so, it's important to take a proactive approach with antiemetics because once nausea and vomiting begin, they're much more difficult to control.
Commonly used antiemetics include:
- Ondansetron (Zofran)
- Dolasetron (Anzemet)
- Granisetron (Kytril)
- Aprepitant (Emend 09)
- Palonosetron (Aloxi)
- Dexamethasone (Decadron)
- Dronabinol (Marinol)
- Metoclopramide (Reglan)
Anxiety also plays an important role in triggering nausea, Keyssar says. Experts don't know why, but people with high levels of anxiety tend to experience more nausea. And, ironically, the worry itself can make nausea more likely. To prevent this from happening, ask the doctor about medications such as lorazepam (Ativan) to treat anxiety, Keyssar says.
Another way to prevent nausea from hitting as severely after chemo: Eat a light meal a couple of hours before each treatment.
Treatment for nausea
In addition to treatment with antiemetics before chemotherapy, many medications -- including those mentioned above -- are available to help control vomiting and nausea on an ongoing basis. Keep in mind that if the first medication your doctor tries isn't effective, it doesn't mean another one won't work. Every patient's response is individual, and finding a solution is often a process of trial and error.
Likewise, one medication may work for a while and then mysteriously lose its effectiveness. Doctors have an arsenal of medications to chose from, so don't hesitate to call and request a switch.
Another option is to combine drug-based antinausea treatment with alternative approaches. In recent years, many breast cancer patients have found that simultaneous treatment by an herbalist specializing in Chinese herbal medicine (CHM) can make a big difference in reducing nausea and vomiting and strengthening the body to withstand chemotherapy. Acupunture has been shown to be effective.
With the recent publication of a study in the Annals of Oncology showing a significant reduction in nausea among patients treated with CHM, many leading cancer centers are starting to incorporate this alternative treatment.
If this approach sounds appealing, ask the doctor about additional treatment by a CHM practitioner or look for a clinic specializing in such a program, which can coordinate communication between the CHM specialist and your doctor.
Many cancer patients have found that smoking marijuana reduces nausea and stimulates appetite. It's currently legal in eight states for this specific purpose, although there are conflicts between national and state laws, and the issue is complex. For more information, contact the National Organization for Reform of Marijuana Laws ( NORML)
Coping with nausea
In addition to medication, you're probably going to have to take other steps to help control nausea. Luckily, there are many little ways to make a big difference.
Eat small meals. Eat many small meals throughout the day rather than three large ones can do a lot to conrol nausea.
Keep lots of snacks available. High-carbohydrate foods like crackers and toast help settle the stomach and move through the digestive system quickly. Keep snacks next to the bed so you or the person in your care can have a few bites before getting up. Keep jars of candy, nuts, dried fruit, small crackers, and other snacks around the house.
Avoid unpleasant smells. Scents can be powerful nausea triggers for someone undergoing chemotherapy. Take steps to avoid strong odors -- move the garbage can to the garage, put the cat litter downstairs, park the car at the curb, so exhaust fumes don't fill the garage.
Take particular care to avoid food-related smells before meals, which can set off a wave of nausea. Avoid food with a strong smell, such as fish, and serve or eat meals cool or at room temperature when possible, since hot food tends to have a stronger odor.
Try enhancing the taste of food -- without odors -- by seasoning with salt, lemon juice, and condiments like catsup, pickles, and olives.
Encourage rest after meals. Activity slows digestion, which tends to increase nausea. One good strategy: Take a rest after eating, either sitting up or with back and shoulders raised on pillows. Avoid lying flat on your back, as this can cause heartburn and nausea. Loosen clothing and keep the room cool, with plenty of fresh air.
Offer plenty of liquids. Drinking lots of water helps prevent nausea, but other liquids are good too. Flat ginger ale is popular with cancer patients, as is cold ginger and peppermint tea, as well as other types of herbal teas. Ice chips are popular, but if they get boring, frozen fruit ice pops work well.
Prevent sour mouth. A dry, sour taste in the mouth is a common side effect of breast cancer treatment, and it can also trigger nausea. Many patients find that it helps to rinse their mouth out with water as often as possible, particularly before meals. Chewing on peppermint candy, lemon drops, or ginger candy also helps.
Try distraction after meals. Thinking about something else can help prevent nausea from occurring after meals. Get out a board game or watch a movie. Many people also find that relaxation techniques such as guided meditation help reduce nausea.
The main thing to keep in mind about breast cancer-related nausea is that it's an ever-evolving process that you have to take day by day. Some days will be bad days, when your main focus will be keeping as comfortable as possible. Other days will be good days, when you can take advantage of feeling better to eat well and build up strength.