Dry Mouth (Xerostomia)

OncoLink
Last Modified: September 17, 2012

Dry mouth is most commonly caused by radiation therapy given to the head and neck region of the body. During radiation therapy, saliva production is actually increased due to irritation caused by the radiation or the chemotherapy (if administered). Patients receiving radiation to the head and neck may experience a change in the production and quality of saliva in the major and minor salivary glands. During treatment the saliva tends to be thicker, often described by patients as "ropey" and difficult to mobilize. After treatment, the excessive saliva dissipates and the mouth becomes dry. This can be a temporary side effect, resolving completely or partially over the year after treatment, or result in a permanent loss of saliva production.

Dry mouth may affect speech, taste sensation, ability to swallow, and the use of dentures. Patients may complain of a sore or burning sensation, cracked lips, and fissures in the corners of the lips. There is also an increased risk of cavities, periodontal disease and ultimately, tooth loss due to less saliva. Normal saliva contains enzymes that protect the teeth and gums from bacteria, keeping them healthy.

Can Dry Mouth Be Prevented?

There are medications and techniques aimed at preventing or reducing xerostomia.

IMRT (intensity modulated radiation therapy)may reduce the extent and permanence of xerostomia. With IMRT, the salivary gland on the side opposite of the cancer receives a lower dose of radiation; therefore salivary function may recover after 6 to 12 months following the completion of treatment. This is dependent upon the dose as well as the percentage of the salivary gland that receives radiation therapy.

Amifostine, a radiation protector of normal tissues, has been shown to protect the salivary glands when given daily with radiation therapy, although logistics and side effects have limited its use in practice. Furthermore, it is not clear what benefit Amifostine adds when modern radiation techniques such as IMRT are utilized since treatment with Intensity Modulated Radiation Therapy (IMRT) or Proton therapy may allow the radiation oncologist to spare the salivary glands from getting significant radiation dose. This may prevent dry mouth in the future. There is also some concern that Amofostine may be a radioprotectant. Meaning it may protect the tissues in the treatment area from the radiation, meaning the cancer cells would not receive the treatment.

If you are getting radiation therapy to the head and neck region, you should discuss these options with your radiation oncologist.

What Can I Do If I have Dry Mouth?

If you have developed xerostomia, there are management strategies that can effectively deal with your dry mouth and prevent cavities and periodontal disease. Try to follow these simple guidelines:

Perform oral hygiene at least four times per day (after each meal and before bedtime).
Floss once a day
The mouth (oral cavity) should be rinsed immediately after meals.
Dentures need to be brushed and rinsed after meals.
Only use toothpaste with fluoride when brushing.
Keep water handy to keep the mouth moist at all times. Sip water or spray it in the mouth regularly.
Apply prescription strength fluoride gel at bedtime unless you do not have any teeth.
Rinse with salt and baking soda solution 4-6 times a day (½ tsp. salt, ½ tsp. baking soda, and 8 oz of water).
Chew sugar free gum/suck on sugar free hard candy or drink diet ginger ale to stimulate saliva production.
Avoid liquids and foods with high sugar content.
Limit coffee, tea and alcohol as these will make dry mouth worse. Caffeine products such as coffee, tea and colas also act as diuretics.
Avoid dry foods, such as bread, dry meat, toast, crackers, and snack foods that are dry and salty.
Add sauces or gravies to food to make them more moist.
Avoid rinses containing alcohol.
Avoid antihistamines, which can dry the area further.
Use moisturizer regularly on the lips
Salivary substitutes or artificial saliva preparations may relieve discomfort by temporarily wetting the mouth and replacing some of the constituents of saliva.
Oral pilocarpine (Salagen) is the only drug approved by the FDA to stimulate saliva secretion from the remaining salivary glands. It is not a drug for everyone with dry mouth, and it can only be obtained with a prescription from your doctor.
Biotene® products (mouthwash, toothpaste, chewing gum that has the pH of saliva) are available without a prescription and can be effective for treating dry mouth.
Use a cool mist room humidifier at night in the bedroom to provide humidity, especially in winter months when the house is heated.
See your dentist every 3 months for cleaning and a dental health check up.
Acupuncture may increase saliva production for people that have some saliva