Worried About Nausea? Read This.

Antiemetics help patients avoid a much-feared side effect: chemotherapy-induced nausea and vomiting.

By Kari Bohlke, ScD

Nausea and vomiting are among the most feared side effects of chemotherapy. Without effective prevention, these symptoms can have a dramatic impact on quality of life and physical and emotional well-being. The good news is, new, more effective antiemetic (antivomiting) drugs are now available for chemotherapy-induced nausea and vomiting (CINV), offering patients welcome relief.

Understanding CINV

Though many newly diagnosed patients might assume that they will face nausea if their treatment includes chemotherapy, the fact is that the likelihood of CINV varies widely among patients and depends on several factors. The type of chemotherapy that you receive will be the most important factor because some chemotherapy drugs are much more likely than others to cause nausea and vomiting.1 Cisplatin, for example, is considered highly emetogenic (vomit-inducing) and will cause vomiting in most patients without preventive antiemetic treatment. The need for preventive antiemetic therapy, therefore, and the specific approach that will be used, will vary depending on patients’ specific chemotherapy regimens.

Depending on when a patient is generally affected by CINV, the condition is classified as acute (occurring within 24 hours of chemotherapy) or delayed (occurring more than 24 hours after chemotherapy).1 The timing of CINV varies by drug, and an understanding of the expected timing is important in selecting the best antiemetic treatment.

A third category of CINV is anticipatory nausea and vomiting. This most often occurs when a patient has previously experienced CINV and expects to experience it again. Patients with anticipatory nausea and vomiting may find that their nausea begins even before they arrive at the clinic to receive their chemotherapy. Antiemetic drugs appear to have limited effectiveness against anticipatory nausea and vomiting, but behavioral interventions such as progressive muscle relaxation training have shown promise in managing the condition. Because it is generally a learned response, the best approach to avoiding anticipatory nausea and vomiting is to achieve the best possible control of CINV during all cycles of chemotherapy, starting with the first.

Antiemetic Therapy

Antiemetic therapy often starts before chemotherapy begins, and it continues for as long as the risk of nausea persists. Several different types of antiemetic therapy are available, and each type targets a different pathway involved in nausea and vomiting. To achieve the most complete control of CINV, patients may receive a combination of different types of antiemetic drugs.

Some of the more common antiemetic medications are the following:1

• 5-HT3 receptor antagonists. This class of drugs provided a major breakthrough in the prevention of acute CINV. Drugs in this class include Anzemet® (dolasetron), Kytril® (granisetron) and Sancuso® (granisetron transdermal system), Zofran® (ondansetron), and Aloxi® (palonosetron).
• NK-1 receptor antagonist. Emend® (aprepitant) is the first of a newer class of drugs known as NK-1 receptor antagonists. It has been shown to add to the activity of 5-HT3 receptor antagonists and dexamethasone and is effective against both acute and delayed CINV.
• Corticosteroids. Dexamethasone is often used alone or in combination with other antiemetic drugs for the prevention of both acute and delayed CINV.

The choice of which drugs to use (if any) and when to use them will depend on the type, dosages, and schedule of the chemotherapy you receive.

Other Ways to Feel Better

In addition to taking any medications your doctor prescribes, the National Cancer Institute recommends the following steps for reducing chemotherapy-induced nausea and vomiting:

Stay away from some foods.

• Avoid greasy, fried, salty, sweet, or spicy foods if you feel sick after eating them.
• If the smell of food bothers you, ask others to cook for you. Then let the food cool before you eat it.

Have enough to eat and drink.

• Take small sips of water during the day if you find it hard to drink a full glass at one time.
• Eat five or six small meals during the day instead of three big meals.

On days you get treatment:

• Talk with your nurse to learn about ways to relax if you feel sick before treatment.
• Learn the best time for you to eat and drink. Some people feel better when they eat a little just before treatment. Others feel better when they have nothing to eat or drink before treatment.
• After treatment, wait at least one hour before you eat or drink.

Foods and drinks that are easy on the stomach include clear broths, clear sodas, water, crackers, noodles, oatmeal, white toast, white rice, boiled potatoes without the skin, broiled or baked chicken without the skin, bananas, popsicles, and canned fruit.

Take Action

It’s important for patients to understand that tremendous advances have been made in managing the side effects of cancer treatment. Side effects such as chemotherapy-induced nausea can now be prevented or reduced in many cases. Talk with your healthcare team about the possible side effects of all your cancer treatments, and find out what steps you can take before, during, or after cancer treatment to prevent or manage these side effects.

Pill? IV? Patch? Patients Have Options.

Antiemetics have commonly been given orally (by mouth) or intravenously (into a vein). A more recent option is a patch that sticks to the skin and delivers a steady dose of granisetron over a several-day period. Research suggests that the Sancuso® patch is as effective as oral granisetron.

Does Marijuana Relieve Nausea and Vomiting?

Marijuana is derived from the Cannabis sativa plant, which contains substances known as cannabinoids that act on specific receptors in the brain. Early research on cannabinoids (given orally) suggested that they provide some relief against chemotherapy-induced nausea and vomiting. Since that time more-effective antiemetic drugs have been developed and are the preferred initial choice for prevention of CINV. Cannabinoids may provide a benefit, however, when other antiemetic treatments fail. Two drugs that contain synthetic cannabinoids—Marinol® (dronabinol) and Cesamet® (nabilone)—have been approved for this purpose.

Ginger Supplements May Provide Benefit

A study presented at the 2009 annual meeting of the American Society of Clinical Oncology evaluated the addition of ginger supplements to standard antiemetic therapy. Patients who received the ginger supplements reported less nausea than patients who received placebo supplements. The researchers cautioned, however, that patients should speak with their doctor before taking ginger or any other supplement.

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