Managing the Symptoms of Dry Mouth

Stuart A. Kay, DDS

Many home parenteral and enteral nutrition (HPEN) consumers complain of dry mouth, or xerostomia. Dry mouth appears to be an indirect consequence of HPEN, a consequence of the underlying condition that leads to HPEN therapy, and/or a side effect of medications HPEN consumers may take. Although xerostomia may not be the most significant problem related to parenteral and enteral nutrition, it can go a long way to diminishing quality of life. Moreover, there are important consequences of dry mouth that can negatively impact both oral and systemic health.

I know. For six months HPN became the central focus of my life as my physicians struggled to close multiple draining enterocutaneous fistulae resulting from a lifetime of Crohn’s disease and numerous post-surgical complications. Prior to HPN I had a relatively mild dry mouth, but it became far worse during this six-month period—whether due to HPN or to not eating, I’ll never know. Although as a practicing oral surgeon I had treated many patients suffering from dry mouth, it wasn’t until I became the patient that I began to understand what dry mouth really meant to my patients, and how much they suffered as a consequence of too little saliva.

Let’s take a close look at the many aspects of dry mouth, with the ultimate goal of developing some useful strategies to alleviate many of its symptoms. First, we need some background information on saliva.   

Saliva Plays Important Role

Although saliva is 99 percent water, it has a number of other components that play important roles. Electrolytes contribute to the buffering capacity of saliva and help in the remineralization of tooth enamel; enzymes start digestion of starch and fat before food is swallowed and kill bacteria; mucin proteins assist with lubricating oral soft tissues (i.e., lips, tongue, and cheeks); and opiorphin is a natural pain-killing substance.

Saliva is produced by the parotid, sublingual, and submandibular glands, as well as hundreds of minor salivary glands found in the palate, lips, and other structures of the mouth. Normal daily output of saliva is approximately 1 liter per day, with salivary flow fluctuating by as much as 50 percent with our daily rhythms. The quantity and quality of our saliva are in part dependent upon normal nerve functioning. When we’re calm, our parasympathetic nervous system induces more watery secretions. When we’re under acute anxiety or stress, sympathetic nerve stimulation produces a sparser, thicker salivary flow, leading to sensations of dryness.

Functions of Saliva

  • Saliva is necessary for a healthy and normal mouth. Saliva serves multiple functions in addition to those mentioned above:

  • Saliva helps maintain a neutral oral pH, thereby neutralizing potentially damaging acidic foods and liquids.

  • Salivary lubrication of our oral tissues keeps them intact, thereby protecting these tissues from bacterial invasion and infection.

  • Minerals in saliva can repair microscopic tooth decay. In addition, the mechanical action of saliva is important in helping wash food and debris away from our teeth and gums, a function important in preventing decay and periodontal/gum disease.

  • Saliva facilitates swallowing by lubricating our food. Further, in making our food soluble, it makes it available to the taste buds located in the back of our tongue. It is an important factor in our ability to taste normally.

  • Normal salivary lubrication facilitates speech.

  • Saliva decreases the amount of plaque (thin bacterial film) on our teeth, thereby reducing the risk of periodontal disease.

  • Proper salivary flow reduces the risk of fungal overgrowth in our mouths. Specifically, saliva helps prevent the development of oral candidiasis.

Common Signs and Symptoms

We all know what a parched mouth feels like. Clearly it’s an uncomfortable, unpleasant sensation. There are, however, very specific signs and symptoms that correlate with hyposalivation (a decrease in or lack of salivary flow). Here are some of the more common signs and symptoms of too little saliva:

  • A sticky, dry feeling in the mouth or throat

  • Trouble chewing, swallowing, or speaking

  • Burning sensation of the tongue, lips, or cheeks

  • A sensation of a loss of or altered taste

  • Saliva that seems thick and stringy

  • Bad breath

  • A rough, dry tongue; tongue often feels cracked or excessively fissured

  • Cracked lips, often with sores or split skin at the corners of the mouth

  • Increased and persistent plaque on the teeth; teeth feel “slimy” and unclean

  • An increase in tooth decay, especially along the gum line

  • Evidence of the fungus Candida albicans (thrush) in the mouth or throat (manifestations include excessive redness of oral tissues; white, curdlike patches that stick to the tongue and cheeks and result in bleeding if rubbed off; inflamed and often painful fissures at the corners of the mouth)

Causes of Dry Mouth

Many articles, and even some textbooks, examine the myriad causes of dry mouth. Here we’ll look at some of the major underlying reasons for dry mouth, with a special emphasis on how PEN may indirectly contribute to the problem.

Lack of Chewing

In preparing for this article I had a conversation with Dr. Leo Sreebny, one of the world’s foremost experts on dry mouth. After learning who would be reading this article, Dr. Sreebny immediately yelled into the phone, “Chew…tell them to chew.” According to Dr. Sreebny, chewing is critical to stimulating normal salivary flow. Chewing, whether you swallow or not, initiates reflexes that lead to salivation. No chewing leads to minimal, if any salivary flow.

Medications

Dry mouth is a common and significant side effect of over eighteen hundred drugs, both prescribed and over-the-counter, in more than eighty drug classes. According to Dr. Sreebny, this is the number one cause of xerostomia in the world today. As a general rule, the greater the number of drugs being taken, the greater the risk of developing dry mouth. Common classes of medications that frequently result in dry mouth symptoms include antihistamines and other anti-allergy medications, decongestants, cardiovascular drugs for hypertension, antidepressants, sedatives, painkillers, antacids, anti-Parkinson’s medications, muscle relaxants, and antiemetics.

Medication-induced dry mouth may result from neural effects to the salivary glands which are generally reversible. Although eliminating the offending medication will likely improve salivary flow, stopping an offending medication is often not possible. We’ll examine other strategies that may be effective when we look at solutions to dry mouth.

Systemic Disease

A number of systemic diseases are associated with dry mouth, Sjögren’s syndrome being perhaps the most notable. Primary Sjögren’s syndrome (pronounced “showgren’s”) is limited to the eyes and salivary glands, producing both dry eyes and dry mouth. Secondary Sjögren’s syndrome is associated with autoimmune or connective tissue diseases, i.e. rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis (scleroderma). Other autoimmune diseases associated with dry mouth are fibromyalgia, chronic fatigue syndrome, and Raynaud’s phenomenon. In addition, the following are frequently associated with complaints of dry mouth: chronic active hepatitis, HIV, AIDS, bone marrow transplantation, renal dialysis, diabetes (especially when poorly controlled), graft-versus-host disease, vasculitis, and primary biliary cirrhosis.

Radiation Therapy

Cancer of the head and neck regions, including the oral cavity, nose, sinuses, “throat” (larynx and pharynx), and esophagus is often treated with radiation therapy. Radiation therapy can injure both major and minor salivary glands. As a consequence, the salivary glands atrophy, resulting in varying degrees of either temporary or permanent dry mouth.

Dehydration

Fluid loss is often an everyday struggle for many Oley Foundation members. Even though I am no longer on HPN, fluid loss through my ostomy continues to be part of my reality, a part that needs my careful attention. Dehydration, of course, is the inevitable result of poorly managed fluid loss, with all of its signs, symptoms, and systemic effects. Dry mouth will almost always be one of the signs of dehydration. Happily, adequate hydration will quickly reverse this cause of dry mouth.

Depression and Stress

To be human is to experience anxiety, stress, and depression. Add the need to manage daily HPEN, as well as our individual health problems, and stress can easily become a frequent companion. One of the consequences of chronic or acute stress and depression is dry mouth. Although clearly not the most urgent stress-related problem, dry mouth can exacerbate the stress and anxiety we’re already feeling. To make matters worse, many of the medications used to treat anxiety and depression, i.e. selective serotonin reuptake inhibitors (SSRIs), often have dry mouth as a frequent side effect. Developing healthy strategies and coping mechanisms that can reduce our everyday anxieties and stress to manageable levels will not only help elevate our quality of life, but may also help to reduce our sensations of a dry, uncomfortable mouth.

Strategies for Relieving Dry Mouth

For most of us with problems requiring HPEN, the causes of dry mouth are numerous and complex. Solving one reason alone for dry mouth is unlikely to eliminate the problem. As with many chronic health problems, managing rather than curing the problem of dry mouth is generally more realistic. Happily for most of us, strategies exist that can reduce this unpleasant problem so it no longer interferes with our quality of life.

Medications

As noted earlier, the medications we’re on are often a major cause of dry mouth. The greater the number of these drugs taken per day, the greater the oral dryness. Given these facts, what strategies are available to help diminish the negative impact medications may have on our oral tissues?

First attempt to identify what drugs may be causing oral dryness. Your physician may be able to help identify the offending medication. The following Web site will also help you identify most medications that produce a dry mouth: www.drymouth.info/consumer/SearchForDrugs.asp. Discuss with your physician possible substitutions that may have less of an oral drying effect.

Many of us have several medical caregivers, who each prescribe different medications. Make sure all your caregivers are aware of all the medications you’re taking. It may be possible to eliminate some of the medications you’re now on. Remember, the greater the number of medications, the more severe the oral drying.

In general, the intensity of oral dryness is directly related to the level of the offending drugs in the blood. The higher the blood level, the more severe the dryness. Changing the way a medication is taken may reduce the level of oral dryness. For example, dividing a prescribed dose into smaller, more frequently taken doses may reduce the dryness. It’s important, however, that you first consult your physician and discuss whether you can change the dosing pattern.

The degree to which we experience oral dryness often varies throughout the day. You may find some relief by altering your drug-dosing schedule so that those times when your mouth is most dry do not coincide with taking the offending medication.

Instituting some of these strategies will likely not eliminate oral dryness altogether, and in some cases will not help at all. However, it is likely one or more of these suggestions will lead to fewer symptoms of dry mouth. It’s worth a try.

Lack of Chewing

Remember Dr. Sreebny’s admonition to chew? Chewing is critical to stimulating normal salivary flow. No matter what the primary cause of your dry mouth is, lack of chewing will guarantee a dry mouth. Note that I did not say “eating.” It is not necessary for you to swallow food in order for chewing to be effective. Eating may not be possible if your bowel is obstructed or you cannot swallow, but chewing usually is.

The easiest and most convenient way to chew is to chew pleasant-tasting, long-lasting gum. Let’s take a closer look at some of the basics of gum and gum chewing.

First and foremost choose a sugar-free gum. Gums that contain sugar, usually in the form of sucrose, have several negative effects: (a) They produce an acidic pH to the saliva, which in turn tends to erode tooth enamel and ultimately leads to tooth decay; (b) Sucrose increases the population of decay-producing bacteria in the mouth, especially Streptococcus mutans.

There is some evidence that cinnamon-flavored gum may have an antibacterial effect, thus reducing the potential for dental decay and possibly even periodontal disease.

Gum with the natural sugar substitute xylitol may be the most appropriate product for those with dry mouth. Xylitol is a natural sweetener found in many fruits and vegetables. It is most often extracted from birch trees, corncobs, or other natural sources. Xylitol does not require insulin to be properly metabolized and can serve as a sugar-free sweetener for diabetics. Xylitol does not support bacterial growth, thus one of its primary benefits is decreasing the incidence of dental decay. Xylitol also reduces plaque formation, making plaque on teeth less adhesive; it neutralizes plaque acids and stimulates salivary flow; and it assists in the remineralization of tooth enamel.

In order to obtain the oral benefits of xylitol, including its salivary-stimulating effects, six to ten pieces of gum should be chewed daily, and each for a lengthy period of time. On average there is 1 gram of xylitol in a piece of gum, leading to a maximum of 10 grams of xylitol per day. At high doses, i.e. 45 grams per day for children and approximately 100 grams per day for adults, xylitol may cause diarrhea. There is no need to ingest these doses to obtain xylitol’s oral benefits. [Editor’s note: It is uncertain what amount of xylitol or sorbitol may cause or exacerbate diarrhea in consumers with short bowel syndrome.]

The following gums contain xylitol: Zapp! Gum; Epic Xylitol Gum; Spry Gum with 100% Xylitol; Ricochet Gum by Emerald Forest; Trident® Sugarless Gum with Xylitol (and sorbitol); Biotène® Dry Mouth Gum (also contains sorbitol). The best way to purchase some of these products may be online. You can also obtain detailed information on the ingredients in each piece of gum if you go online. Sorbitol, another sugar substitute often found in gum, has a similar benefit and similar potential to cause bloating, flatulence, and diarrhea if taken in large amounts.

Oral Hygiene

Regardless of the reasons for dry mouth, or its severity, there are a number of local procedures we can do to reduce our dry mouth symptoms, as well as to diminish or eliminate some of the negative consequence of oral dryness. Some of these simple oral hygiene strategies can help improve our everyday quality of life.

Toothbrushing and flossing: As discussed earlier, lack of proper salivation predisposes us to increased incidence of decay and periodontal disease. Without adequate amounts of saliva, sticky, bacterial-laden plaque tends to remain on our teeth. Toothbrushing and flossing therefore become especially important in the presence of oral dryness.

You should brush and floss several times each day. However, lack of adequate salivation tends to desiccate our oral tissues, making them unusually susceptible to local trauma, including toothbrushing. Use only very soft-bristled toothbrushes in order to avoid cutting and abrading fragile gums and adjacent tissues. In addition, avoid using excessive pressure when brushing. A light, gentle touch, even with the softest bristled toothbrush, will adequately remove debris and harmful plaque from teeth.

Toothpastes and mouthrinses: Using toothpastes and mouthrinses specially designed for people with increased oral dryness will avoid burning cracked, dried, sensitive lips, gums, and cheeks. Avoid products containing alcohol. Alcohol, especially in mouthrinses, will further desiccate already sensitive oral soft tissues, making them more prone to cracking, abrasions, and increased sensitivity. In addition, dry mouth toothpastes and mouthrinses should contain no sodium lauryl sulfate, a commonly used ingredient that can cause apthous ulcers (canker sores), further damaging already fragile oral soft tissues.

The following toothpastes are recommended for people with dry mouth: Orajel® Dry Mouth Moisturizing Toothpaste; Tom’s of Maine® Clean and Gentle Care SLS-Free Anticavity plus Dry Mouth Soother Toothpaste; and Biotène Dry Mouth Toothpaste. I have personally been using Biotène Dry Mouth Toothpaste for many years. It contains xylitol but not sodium lauryl sulfate, and also contains an enzyme system that may mimic the effects of naturally occurring salivary enzymes.

Rinsing multiple times daily with properly designed mouthwashes is important for removing food and other oral debris that normally would be eliminated by proper salivary flow. These mouthrinses are recommended for people with dry mouth (none listed contain alcohol): Biotène Mouthwash with Xylitol (contains the same enzyme system as the toothpaste); Oasis® Moisturizing Mouthwash; Tom’s of Maine Cleansing Mouthwash; and Crest Pro-Health™.

Tongue cleaning: Lack of normal salivary flow severely compromises our ability to flush away oral debris and bacteria that accumulate on both teeth and oral soft tissues. In particular, the entire surface of our tongue, especially in the posterior regions, becomes impregnated with billions of odor-producing bacteria. Many of these anaerobic bacteria (do not need oxygen to thrive) produce volatile sulfur compounds, giving our breaths a rotten-egg odor. It is critical to clean the surface of the tongue, especially after awakening. Since most of the odor-producing bacteria lodge in the crevices at the back of the tongue, make a special effort to carefully clean this back region.

There are several methods to effective tongue cleaning: (1) You can brush your tongue with a toothbrush. While this maneuver can be effective, it’s difficult to thoroughly clean your tongue with the soft toothbrushes required in oral dryness. (2) You can scrape the surface of your tongue with the edge of a spoon. This technique is often more effective than using a soft-bristled toothbrush. Rinse the spoon clean of debris after each scraping before continuing. (3) Use a professionally designed tongue cleaner or scraper. Using a specially designed tongue cleaner is by far the best method to clean your tongue. I have been using inexpensive, plastic tongue scrapers for years. They’re effective and work well.

Perhaps the best strategy is to ask your dentist for particular tongue cleaner/scraper suggestions. Then ask for a lesson on the best way to use the cleaner. The tongue cleaners I have been using for more than a decade are the BreathRx® Gentle Tongue Scrapers from Discus Dental. Only dental professionals can order products from Discus Dental, so you may want to ask your dentist to help you purchase the scrapers. However, there are many other equally effective tongue cleaner/scrapers that you can purchase directly. Just go online, search for “tongue cleaner/scraper,” and you’ll be on your way to a cleaner, more pleasant-smelling tongue.

Saliva Substitutes/Oral Lubricants: Despite all these efforts, our mouths may remain uncomfortably dry. Over-the-counter saliva substitutes and oral lubricants may help ameliorate the distressing sensations of oral dryness. Formulated either as solutions, sprays, or gels, the primary purpose of these products is to coat dry oral tissues with lubricants that may make chewing, swallowing, and speaking easier and more comfortable. Effectiveness varies from individual to individual, but some degree of relief from dry tissues can be expected.

Saliva substitutes are designed to mimic the chemical and physical characteristics of saliva. They normally contain a mixture of buffering agents, ions, cellulose derivatives designed to lubricate and increase viscosity, and flavoring agents. Generally lacking are antibacterial and digestive enzymes and other proteins found in saliva.

Saliva substitutes are designed to be used frequently, and unless otherwise indicated, can be safely swallowed. Oral Balance®, a gel, claims to provide hours of relief, although most saliva substitutes provide only short periods of lubrication. Some examples of over-the-counter saliva substitutes you may want to try include: Oral Balance Gel with Xylitol (Biotène); Salivart® (spray formulation); Mouth Kote® (spray formulation); Moi-Stir® (spray formulation); and Thayers® Dry Mouth Spray. You may need to sample a number of these products until you find one that works best for you.

Conclusion

My hope in writing this overview of dry mouth (xerostomia) was to help improve, even if only slightly, the lives of Oley Foundation members on HPEN. Although I’ve tried to be as comprehensive as possible, in reality this document represents only a first step in helping you manage one small challenge among the many you face. It’s sometimes said that within each challenge lies a solution ready to be discovered and implemented. In this case, learning to more effectively manage your dry mouth symptoms may, in a small way, help you live a freer, happier, and more comfortable life.

Useful Web Sites for People with Dry Mouth

Drymouth.info
www.drymouth.info/consumer/default.asp

NIH Clinical Symptom Research: Dry Mouth & Salivary Dysfunction
http://symptomresearch.nih.gov/chapter_27/index.htm

Biotène
www.Biotene.com

Mayo Clinic
www.mayoclinic.com/health/dry-mouth/HA00034

Sjögrens Syndrome Foundation
www.sjogrens.org/

Consumer Guide to Dentistry
www.yourdentistryguide.com/dry-mouth/