Dry Mouth

Also called: xerostomia

People with cancer can develop mouth (oral) problems from their cancer treatments. Mouth problems are often a result of inflammation and destruction of normal cells and glands in the mouth.

Dry mouth can cause difficulty with chewing, swallowing and talking. Xerostomia refers to a dry mouth because of a decrease in the quality and amount of saliva. Saliva helps break down food and helps digestion. Saliva also helps prevent infection in the mouth and tooth decay by decreasing acid and cleaning teeth and gums. With less saliva, the mouth cannot clean itself properly and minerals from the teeth can be lost.

If dry mouth as a result of cancer treatment is severe enough, it can interfere with a person's ability to maintain good nutrition. There are steps the healthcare team takes to check for, prevent and control a dry mouth. A registered dietitian can also give suggestions on how to cope with a dry mouth when it affects eating and how to maintain nutrition.

Causes

• The most common cause of xerostomia is radiation therapy to the head, neck or mouth area. Radiation can affect the production and flow of saliva from the salivary glands, resulting in a dry mouth.
• If salivary glands are removed during surgery for salivary gland or oral cancer, this can also cause a dry mouth.
• Some drugs, such as antihistamines (allergy medicines) or opioids, can also cause a dry mouth.

Symptoms

• sticky, dry feeling in the mouth and/or throat
• thick, stringy saliva
• a sore or burning feeling in the mouth
• dry, cracked lips and tongue
• increased thirst
• changes in taste, swallowing, and speech
• problems with dentures

Dry mouth occurs within the first 2 to 3 weeks of radiation treatment to the head and neck area and can become worse over time. A dry mouth may be temporary or in some cases it can become a long-term problem. This depends on the dose of radiation used and the number of salivary glands radiated. The salivary glands may recover partially, often within the first year after radiation therapy. A complete recovery and return to normal functioning is unlikely.

Management

• Sip water frequently or suck on ice chips. Carry a water bottle, so it is convenient for frequent sipping. Sip on juices and other fluids throughout the day. Avoid foods and liquids that contain a lot of sugar or are acidic, as they can contribute to tooth decay.
• Limit drinks with caffeine, such as coffee, tea and some soft drinks. Caffeine can dry out the mouth.
• Rinse the mouth with water before eating.
• Sip water or a sugarless drink during meals. This will make chewing and swallowing easier.
• Sip on club soda to help loosen thick saliva.
• Suck on sugarless hard candy or chew sugarless gum to stimulate salivary glands.
• Eat soft foods that are cool or at room temperature. It may be helpful to blend foods into a purée.
• Use butter, margarine, cream, milk, broth, soup, gravy or sauces to help moisten foods and make them easier to chew and swallow. Have gravy prepared and ready to add to meat, potatoes and vegetables.
• Dunk or soak dry foods in liquids.
• Limit salty or spicy foods.
• Avoid alcohol and tobacco.
• Continue good dental hygiene and mouth care during and after cancer treatment to help reduce problems, such as cavities:
  • Clean the mouth and teeth often (at least 4 times a day) using a soft-bristle toothbrush.
  • A fluoride toothpaste, rinse or gel may be recommended.
  • Rinse the mouth after meals and before bed with a solution of salt or baking soda and water. There are many different recipes for mouth rinses, so check with the healthcare team to see what they recommend and the amounts of salt or baking soda to use as these can vary among cancer treatment centres. A combination of salt and baking soda may also be used. Baking soda may help to thin saliva and decrease the acid effect of xerostomia, but this last effect may also promote bacteria growth.
  • Do not use mouthwashes that contain alcohol. These dry the mouth even more.
  • Avoid lemon glycerine swabs, which dry the mouth.
• A saliva substitute (artificial saliva) may be recommended. Artificial saliva products are available, such as mouth rinses, sprays or gels. Ask the healthcare team about other products to moisten the mouth. Sometimes a medication called pilocarpine (Salagen), which stimulates the salivary glands to make saliva, may be prescribed.
• Keep lips moist with a water-based lip balm and ask the healthcare team about other types of lip balms or moisturizers that are good to use.
• A room humidifier may help relieve dryness.
• Have regular dental checkups and talk to the dentist about other ways to help care for your teeth, mouth and gums and prevent tooth decay.