Dry Mouth - Xerostomia

Prevention and management of cancer treatment related dry mouth.

by Dr. C.H. Weaver M.D. 3/2019

Dry mouth is a side effect of some cancer treatments. It may be a direct or indirect result of treatment. Saliva is necessary for taste, swallowing and speech. Therefore, a dry mouth can significantly impact daily activities and quality of life. Dry mouth treatment consists of symptomatic relief through stimulation of salivary flow, oral aids to decrease discomfort or intervention with medications.

Which treatments are likely to cause a dry mouth?

The most common therapy for cancer that causes a dry mouth is radiation therapy for head and neck cancers. The radiation damages the primary salivary glands in the mouth that generate saliva and produce a “wet” feeling, reducing their production of saliva.

Mouth sores are a side effect of many chemotherapy drugs, and this condition is sometimes called mucositis. Once you have mouth sores, you may also develop symptoms of a dry mouth. Most chemotherapy drugs can cause mouth sores, but this side effect is more frequent in patients who have been treated with the chemotherapy agents listed at the end of the article. Learn about Mucositis

What are the symptoms of a dry mouth?

  • A small amount of thick or stringy saliva
  • A sore or burning feeling (especially on the tongue)
  • Changes in the surface of the tongue
  • Taste changes
  • Cracked lips
  • Cuts or cracks at the corners of the mouth
  • Changes in your ability to articulate or speak clearly
  • Difficulty wearing dentures

In addition to aiding in taste, swallowing and speech, saliva is also important for protecting your teeth against tooth decay. Eating sugary foods leaves acid in your mouth, which causes minerals to be lost from your teeth, leading to tooth decay. Saliva protects your teeth by neutralizing this acid.

Because saliva is a lubricant, it also acts to protect the cells that line your mouth. Without enough lubricant, the lining of your mouth becomes more susceptible to damage. Simply brushing your teeth or eating certain foods can damage the lining of your mouth. Once you get a small cut, it may not heal normally and can develop into a mouth sore that can be very uncomfortable and may make it difficult to eat.

What is the treatment for a dry mouth?

Treatment for a dry mouth is aimed at either relieving symptoms or preventing the damage before it happens.

Symptom relief

Oral aids: Your doctor may recommend one of the following to relieve your dry mouth symptoms:(1)

  • Sipping water
  • Gargling with a salt and soda mouthwash
  • Biotene mouthwash or spray
  • Artificial saliva spray

Pilocarpine (SalagenÒ) tablets: The drug pilocarpine stimulates salivary flow from the minor salivary glands that are known to be rich in mucin, a component of saliva that acts as a lubricant and protects the lining of the mouth and throat. Pilocarpine appears to be moderately effective in relieving symptoms of a dry mouth. In head and neck cancer patients who received radiation therapy, patients who received pilocarpine used significantly less artificial saliva, hard candy and water for relief of dry mouth symptoms compared to patients on placebo. Furthermore, the patients who received pilocarpine used significantly less artificial saliva, hard candy and water for relief of dry mouth symptoms compared to patients on placebo. In another study, pilocarpine preserved salivary function, but patients still reported difficulties with swallowing (75%), activity (80%), hyposalivation (64%), and taste (81%).(2,3)

Prevention

Amifostine (Ethyol®): Ethyol® is a drug that protects against the damage of radiation. Clinical trials have demonstrated that Ethyol® can reduce dry mouth and may prevent mouth sores. In patients with head and neck cancer that received radiation therapy, 51% of patients receiving Ethyol® experienced a dry mouth compared to 78% of patients receiving radiation therapy without Ethyol®. One year following completion of radiation therapy, only 35% of patients who had received Ethyol® were still experiencing symptoms of a dry mouth, whereas 57% of patients who had received radiation therapy alone were still experiencing symptoms.(4)

Cryotherapy (ice chips): Symptomatic relief from dry mouth can be achieved by sucking ice chips when the chemotherapy drug is most concentrated in the body. This technique, called cryotherapy, works by decreasing blood flow to the cells in the mouth, reducing exposure to the drug and decreasing the risk of developing mouth sores. Furthermore, according to a recent Cochran review, sucking ice is the only measure proven to prevent mouth sores.(5)

Acupuncture is part of a complete medical system developed in China over 3,000 years ago known as Traditional Chinese Medicine (TCM). In the world view of TCM, all life is permeated by a universal force known as qi (pronounced “chee”). The human body contains meridians, energy pathways along which qi flows, and when energy becomes blocked at any location along one or more meridians, illness or disease results. Acupuncture needles are placed at specific points on a meridian, stimulating the points to release stagnant energy.

According to TCM, this returns energy flow to the meridian, restoring balance to the patient on physical, emotional, mental and spiritual levels. Acupuncture has become increasing popular as a complementary medicine in the United States and several formal clinical trials of acupuncture were initiated as a result of a 1997 Consensus Conference convened by the National Institutes of Health. In some instances, acupuncture has yielded positive results. Some of these studies have suggested that acupuncture palliates patients with xerostomia after radiation therapy.

Researchers at the Naval Medical Center in San Diego and the University of California, San Diego conducted a clinical trial of 50 head and neck cancer patients receiving acupuncture for radiation therapy-induced xerostomia. In their protocol, eight needles were placed per treatment, three in each ear and one in the radial aspect of each middle finger. Concurrently, patients were given a piece of sugar-free candy or a lozenge. The needles were placed by certified physician acupuncturists in sessions lasting from 30-60 minutes. Treatments were repeated one week apart, at which time patients completed a Xerostomia Inventory (XI) to quantify perceived benefit. Patients underwent a total of 318 treatments, averaging five but ranging from 2 to 15. The average follow-up after first treatment was 224 days.

A palliative response, defined as an improvement of 10% or more over the baseline XI, occurred in 70% of patients. Nearly half of the patients reported significant palliative improvement on their XI. Duration of effect for 26% of the patients exceeded three months. No adverse events were linked to the acupuncture sessions.

These results suggest that acupuncture may reduce the severity of xerostomia in head and neck cancer patients that received radiation therapy. These researchers suggest that a regimen of three to four weekly treatments, followed by monthly sessions, may produce optimal results, although some patients achieve lasting response without further therapy. The researchers also acknowledge the need for a controlled, randomized trial to verify these findings. Individuals experiencing xerostomia may wish to speak with their physician regarding the risks and benefits of acupuncture or about participating in a clinical trial.(6) Learn More About Acupuncture

What else can I do?

If you are suffering from a dry mouth, it is very important to maintain good oral hygiene in order to prevent infection or tooth decay. Try to maintain the following:

  • Gently brush your teeth 2-3 times per day. Use a soft bristle brush and warm water to avoid damaging your gums.
  • Rinse 4-6 times per day with a solution of salt and baking soda. Avoid mouthwashes that contain alcohol.
  • Avoid foods and liquids that contain a lot of sugar. Having a dry mouth increases your susceptibility to cavities and sugar causes tooth decay.

Also, try these tips:

  • Drink plenty of water.
  • Eat moist foods with extra sauces, gravies, butter or margarine.
  • Suck on hard candy or try chewing gum.
  • Eat frozen desserts (such as frozen grapes and ice pops) or ice chips.
  • Use a straw to drink liquids.(7)

These Topics May Also be of Interest

Chemotherapy Agents More Commonly Associated with a Dry Mouth

  • Alkeran® (melphalan)
  • hydroxyurea
  • bleomycin
  • paclitaxel
  • busulfan
  • Purinethol® (mercaptopurine)
  • cytarabine
  • mechlorethamine
  • Camptosar® (irinotecan)
  • methotrexate
  • dactinomycin
  • Mutamycin® (mitomycin)
  • daunorubicin
  • Navelbine® (vinorelbine)
  • doxorubicin
  • Novantrone® (mitoxantrone)
  • etoposide
  • Taxotere® (docetaxel)
  • floxuridine
  • Thioguanine® (6-thioguanine)
  • 5-FU
  • Velban® (vinblastine)

References:

  1. Oneschuk D, Hanson J, Bruera E. A survey of mouth pain and dryness in patients with advanced cancer. Support Care Cancer. 2000 Sep;8(5):372-6.
  2. LeVeque FG, Montgomery M, Potter D, et al. A multicenter, randomized, double-blind placebo-controlled, dose-titration study of oral pilocarpine for treatment of radiation-induced xerostomia in head and neck cancer patients. J Clin Oncol 1993; 11: 1124-31.
  3. Fisher J, Scott C, Scarantino CW, et al. Phase III quality-of-life study results: impact on patients’ quality of life to reducing xerostomia after radiotherapy for head-and-neck cancer-RTOG 97-09. Int J Radiat Oncol Biol Phys. 2003 Jul 1;56(3):832-6.
  4. Brizel DM, Wasserman TH, Henke M, et al. Phase III Randomized Trial of Amifostine as a Radioprotector in Head and Neck Cancer. Journal of Clinical Oncology 200;18:3339-3345.
  5. Clarkson JE, Worthington HV, Eden OB, et al. Prevention of Oral Mucositis or Oral Candidisis for Patients with Cancer Receiving Chemotherapy (Excluding Head and Neck Cancer). Cochrane Database Sys Rev. 2000;(2):CD000978.
  6. Cancer, Vol 94, Issue 4, pp 1151-1156, 2002
  7. Overview of nutrition in cancer care: Nutrition suggestions for symptoms relief. http://www.cancer.gov/cancerinfo/pdq/supportivecare/nutrition/patient/#Section_42 accessed 1/14/04.
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