What causes nausea in cancer patients?
Chemotherapy is the number one cause of nausea in 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 cancer treatment include radiation therapy and other medications. Sometimes the cancer itself will make the patient nauseated, particularly if it's a cancer of the digestive system. Cancer-related fatigue is another cause of nausea.
In addition, constipation -- a common side effect of cancer treatment -- can contribute to nausea by slowing down digestion so that the food moves sluggishly through the body. Patients can help reduce constipation by taking in ample dietary fiber and using laxatives if necessary.
Prevention strategies for chemo-related 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 the person you're caring for isn't keen on taking medication for symptoms that haven't appeared yet, explain -- or better yet, have his doctor explain -- that nausea is one of the reasons some patients don't want to continue cancer treatment, so doctors make it a priority to try to control nausea before it starts.
Certain chemotherapy drugs are more likely to cause nausea and vomiting than others. These include:
- Carmustine (BiCNU)
- Cisplatin (Platinol)
- Cyclophosphamide (Cytoxan)
- Dacarbazine (DTIC-Dome)
- Mechlorethamine (Mustargen)
- Streptozocin (Zanosar)
If the chemotherapy regimen includes one of these drugs, he's likely to suffer from nausea and vomiting after treatment. Many other chemotherapy drugs also cause nausea when given at high doses, so find out what drug he's taking and whether the dosage is high or low, so you can anticipate whether he's likely to experience nau sea.
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.
Usually, the doctor will begin treatment with antiemetics before chemotherapy begins, and the treatment will continue for several hours or days after each dose of chemo. 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)
- Lorazepam (Ativan)
Anxiety can also play a key 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, if someone is worried about feeling nauseated, the worry itself can make nausea more likely. To prevent this from happening, ask the doctor about medication 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.
Medications and herbs to control nausea during chemo
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 the 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. The doctor has 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 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.
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 his 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 .
Practical ways to avoid nausea in cancer patients
In addition to medication, there are other ways to avoid or reduce nausea. Even little changes can make a big difference. Try these:
Serve small meals. Prepare food in small, easy-to-serve portions, and suggest that the person you're caring for eat many small meals throughout the day rather than three large ones.
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 he can have a few bites before getting up. Keep jars of nuts, dried fruit, small crackers, and other snacks around the house, and encourage him to eat a handful whenever he can manage it.
Protect the patient from 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 he doesn't have to smell exhaust in the garage.
Ta ke particular care to avoid food-related smells before meals, which can set off a wave of nausea that will keep him from eating. Have him stay out of the kitchen while food is being prepared, and if possible, have him sit outside in the fresh air. Avoid food with a strong smell, such as fish, and serve 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. It can help to take a rest after eating, either sitting up or with his back and shoulders raised on pillows. He shouldn't lie flat on his back, as this can cause heartburn and nausea. Loosen his 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 or other types of herbal teas. Ice chips are popular, but if they get boring, offer frozen fruit ice pops.
Prevent sour mouth. A dry, sour taste in the mouth is a common side effect of cancer treatment, and it can also trigger nausea. Encourage the person in your care to rinse his mouth out with water as often as possible, particularly before meals. Chewing on peppermint candy, lemon drops, or ginger candy also helps.
Distract him after meals . Thinking about something else can help prevent nausea from occurring after meals. Get out a board game or watch a movie together. Relaxation techniques such as guided meditation help reduce nausea as well.
The main thing to keep in mind about 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 the patient as comfortable as possible. Other days will be good days, when you can take advantage of his feeling better to help him eat well and build up his strength. He'll probably appreciate anything you can do to help him weather the ups and downs.