THE CE ANSWER SHEET APPEARS ON PAGE 37 tion of saliva.9 the higher centers of the brain that control the salivary centers, thereby dimin- ishing reflex activity. Mucinous saliva makes the mouth feel sticky, and, for some individuals, the oral cavity may feel dry. An example of this sensation is the dry mouth that is perceived while feeling anxious, nervous or frightened.7,8 Symptoms of drug-induced xerostomia vary with the type of medication Drugs alter the autonomic nervous system and production and secre- Cholinergic drugs bind to muscarinic receptors in the parasym- used.8 pathetic nervous system to stimulate salivary flow and are approved by the U.S. Food and Drug Administration (FDA) for the treatment of Sjögren’s syn- drome and post-radiation of head and neck cancers. Examples include pilo- carpine and cevimeline.10 Affected patients may complain of xerostomia symptoms, as these drugs significantly reduce the volume of serous saliva. It is important to note that most patients do not complain of xerostomia — which is the perception of dry mouth — until half of the normal salivary flow is lost.11 medications that oppose the normal effects of the parasympathetic nervous sys- tem.9 Patients who have lost significant parotid flow often complain of feeling parched, and clinicians may notice intra- oral signs that include enamel demineralization and/or caries, increased biofilm, gingival disease, food packing, poor oral cleansing and halitosis. Medications that oppose the parasympathetic nervous system are used to treat a variety of systemic conditions and include antihypertensives, antidepressants and drugs for treating chronic obstructive pulmonary disease, notably emphysema. Drugs that alter the sympathetic nervous system — including ampheta- mines used for the treatment of attention deficit disorder/attention deficit hyperactivity disorder — are taken by patients of all ages, including children. These individuals may exhibit ropey saliva and/or complain of a “sticky” feel- ing in the oral cavity. Other sympathomimetics include decongestants, appetite suppressants and bronchodilators.7,8,12,13 In addition, drugs may produce symptoms of xerostomia through other mechanisms that are not neutrally mediated. Diuretics contribute to a sys- temic loss of water, resulting in dehydration without any alteration in salivary flow rates. Some drugs produce vasoconstriction of salivary gland vessels. Inhaled medications have been reported to produce the sensation of dry mouth without actually altering salivary flow rates. Many drugs have been reported in the literature as contributing to xerostomia without adequate research to determine if or how salivary flow rates are affected.8 CONSEQUENCES OF CHRONIC XEROSTOMIA Due to the loss of natural salivary immunoglobulins, patients with chronic xerostomia are at high risk for a variety of oral infections, including bacterial (e.g., caries and gingival disease), fungal and viral infections.14 Changes in the chemical composition of saliva include a drop in oral pH due to the loss of buffering by sodium bicarbonate, causing an acid shift that promotes dem- ineralization and caries. The acidity of residual saliva and biofilm also con- tributes to dentinal hypersensitivity. In addition, changes in salivary proteins decrease efficacy of the breakdown of the food bolus during chewing, which may contribute to digestive complaints. Inadequate lubrication leads to oral trauma from foods, oral appliances and prosthetics. Loss of lubrication con- tributes to difficulty with chewing and swallowing, which increases aspiration and choking risks. Clinicians have likely observed that many of their patients take medications for gastroesophageal reflux disease that may be related to chronic xerostomia. Given the large number of individuals affected by xeros- tomia, it is not surprising that proton pump inhibitors (e.g., omeprazole and DecisionsInDentistry.com esomeprazole) are among the most commonly prescribed medications in the United States.15 Conversely, many patients use anticholinergic The systemic azole antifungals include fluconazole, itraconazole and ketoconazole. In 2013, the FDA changed the approval status of ketocona- zole for the treatment of Candidiasis, as the drug is associated with risks for liver injury, adrenal insufficiency and serious drug interactions.17 Recurrent fungal infections may be observed in patients with xerostomia, who may present with a pseudomembranous appearance (i.e., bright red with overlying white pseudomembrane), hyperkeratotic denture stomatitis and/or symptomatic geographic tongue. Angular chelitis is frequently observed, espe- cially in patients with loss of vertical dimension. Intraoral fungal infections are associated with use of steroid inhalers. Recently, the threat level for Candida has been moved up to “serious” by the CDC due to its emergence as a resistant organism.16 Widespread use of systemic azole antifungals has been attributed to promoting resistance. Although systemic antifungal agents are anecdotally preferred by patients, compatibility must be checked with concurrent use of other medications due to the risk for drug interactions and growing concerns for promoting resistance. Topical agents, such as nystatin, should be used for the treatment of oral fungal infections. The systemic azole antifungals should be reserved for exten- sive mucocutaneous infections. Compliance with topical agents is often poor due to the frequency of application and duration of treatment, so the need for therapy must be reinforced. Dentures and oral appliances must be treated as well, and toothbrushes and lip balms/lipsticks disposed, to reduce risk for rein- fection. Twice-daily use of an antiseptic mouthrinse has been shown to reduce denture stomatitis (with the dentures out), as both chlorhexidine and essential oil mouthrinse have been shown to kill seven species of Candida.18 INTERVENTIONS Numerous interventions exist to assist patients with restoring comfort and func- tion, and to reduce adverse oral sequelae associated with chronic xerostomia. Patients should be encouraged to remain hydrated. While salivary replacement agents help temporarily replenish moisture and provide lubrication, not all agents are the same, and clinicians are discouraged from using a “one-size-fits- all” approach with product recommendations. For example, many agents con- tain carboxymethylcellulose to simulate the viscosity of natural saliva, as well as glycerin, which coats the tissues and creates a “slippery” feeling, reducing friction. However, patients who complain of sticky, mucinous saliva may not tolerate these products well, and may prefer products without glycerin. Salivary replacement agents are available in a variety of forms, including lozenges, sprays, rinses and gum. Their effects are short-lived and typically last for only a few hours. To date, the quality of the evidence supporting the efficacy of these products is weak.19 Compliance is problematic for patients who must apply them frequently throughout the day. Further, salivary replacement agents often contain a sugar alcohol, such as xylitol, as a sweetener and anticaries agent. Given that these agents must be used fre- quently and are ingested, dose-control is an important consideration, as the sugar alcohols cannot be metabolized, resulting in adverse digestive effects. ANN ESHENAUR SPOLARICH, RDH, PhD, is a professor, course director of clinical medicine and pharmacology, and director of research at the Arizona School of Dentistry and Oral Health, A.T. Still University in Mesa. She can be reached at [email protected]. The author has no commercial conflicts of interest to disclose. December 2017 • Decisions IN DENTISTRY 31
