Medication-induced xerostomia and caries risk

According to the American Dental Association (ADA), estimates on the prevalence of xerostomia (dry mouth) vary widely from 0.9% to 64.8% in the general population. Individuals with dry mouth may find it difficult to talk, chew or swallow comfortably, and may experience a loss or change of taste (dysgeusia) and poor oral health. Oral dryness also leads to significant levels of discomfort. Patients may experience a considerable decline in nutrition, wellbeing and quality of life. Here we look at the role of medications, and at the increased caries risk associated with xerostomia.

Causes of Xerostomia and the Role of Medications

There are many reasons why dry mouth may occur, including but not limited to medications, autoimmune diseases (e.g., Sjögren’s syndrome), head and neck radiation, chemotherapy, viral infections (e.g., HIV), end-stage renal disease and other conditions. Dry mouth is also reported in individuals with COVID-19.

Medication-induced xerostomia is the most common cause, with hundreds of prescription and over-the-counter medications known to cause the condition. Examples include diuretics, antiseizure drugs, antihypertensives, antidepressants, anxiolytics, antihistamines, antidiarrheals, pain medications, decongestants and muscle relaxants.

Effect on Oral Health

Dry mouth puts patients at significantly greater risk of dental caries, erosion, and other conditions. As Frank Oppenheim, Chairman of the Department of Periodontology and Oral Biology at Boston University, states: “If saliva were [entirely] water, we would have little stumps of teeth or no teeth at all by age 20. We would have dissolved our teeth away.”

Dental caries can have far-reaching consequences. Not only can this seriously impact the patient’s health, it also places a considerable burden on health systems and economies.

Managing xerostomia and Caries Risk

Early diagnosis and management of xerostomia is essential in helping to improve the patient’s quality of life and preventing complications.

1. Ask and Identify

Patients may complain of xerostomia, while others may not. The many potential causes of xerostomia underscore the importance of a thorough medical history, pro-actively asking patients questions during their appointment, and oral examination. An absence of salivary pooling in the floor of the mouth and/or mirrors sticking to a patient's buccal mucosa are indicative of dry mouth. Other signs that may indicate dry mouth and require further investigation (including different potential causes), are:

• Dry and friable oral mucosa

• Dry and fissured tongue

• Enlarged salivary glands

• Dental caries

• Infections, e.g., oral candidiasis

• Mucositis

• Traumatic mucosal lesions

• Angular cheilitis

2. Collaborate

In identifying the causes of xerostomia and developing a treatment plan, it is important to collaborate with other members of the patient’s healthcare team to help ensure a cohesive and effective approach.

3. Relieve Symptoms

To help your patient find relief from the symptoms of dry mouth, you can offer saliva substitutes, artificial saliva products, and oral moisturizers. An alcohol-free, hydrating mouth rinse such as Colgate Hydris can also be recommended. In addition, patient benefit from oral hygiene, self-care, and dietary advice. Patients should be advised to avoid caffeine, alcohol and smoking, as well as spicy, sugary, sticky or salty foods. Patients can of course also be referred to specialists as indicated. For patients with functional glandular tissue, the FDA has approved a number of sialogogues for this purpose.

4. Protection against Dental Caries

Given the high risk of dental caries in patients with xerostomia, a high-level prescription fluoride like Colgate Duraphat Toothpaste (UK and Australia) which contains 2800 ppm fluoride, or Colgate PreviDent 5000 Dry Mouth (US), can be prescribed for daily use instead of regular toothpaste and will provide added protection against dental caries. Specially formulated for patients with xerostomia, Colgate PreviDent 5000 Dry Mouth contains 1.1% sodium fluoride (5000 ppm fluoride) to guard against dental caries and provide superior remineralization of root caries. It is also sls-free. You may also consider an in-office fluoride therapy like Colgate PreviDent Varnish (Colgate Duraphat Varnish).