Dry Mouth (Xerostomia) in Older Adults
Primary Cause and Initial Action
The most common cause of dry mouth in older adults is medication use, particularly drugs with anticholinergic effects, and the first step is conducting a comprehensive medication review to identify and eliminate or substitute offending agents. 1, 2, 3
Causes of Dry Mouth in Older Adults
Medication-Induced (Most Common)
- Polypharmacy is the leading cause of xerostomia in the elderly population, with anticholinergic medications being the primary culprits 2, 3
- Specific medication classes include:
- Older adults frequently require multiple medications for chronic conditions, and many reduce salivary output 1
Age-Related Changes
- Healthy aging does NOT cause xerostomia - salivary gland function is well preserved in healthy geriatric populations 3, 5
- However, saliva undergoes chemical changes with aging: ptyalin decreases while mucin increases, making saliva thick and viscous 3
- Age-related sarcopenia can affect oral and swallowing muscles, contributing to symptoms 4
Systemic Diseases
- Sjögren's syndrome (autoimmune disease affecting salivary glands) 6, 3
- Diabetes mellitus 3
- Chronic kidney disease (alters salivary composition) 7
- Thyroid dysfunction 3
- Nephritis 3
Other Contributing Factors
- Head and neck radiation therapy (high doses) 6, 8
- Chronic mouth breathing 3
- Dehydration 2
- Alcohol and caffeine intake 2
Clinical Consequences Requiring Intervention
Xerostomia causes significant morbidity affecting quality of life:
- Difficulty chewing, swallowing, tasting, and speaking 6
- Poor diet and malnutrition 6
- Decreased social interaction 6
- Oral discomfort, especially for denture wearers (affects denture retention) 6, 3
- Increased risk of dental caries (particularly root caries in older adults with gingival recession and exposed root surfaces) 1, 6
- Risk of periodontal disease and oral infections 2
- Glossodynia (burning tongue), sialadenitis, cracking and fissuring of oral mucosa, and halitosis 3
Treatment Algorithm
Step 1: Medication Review and Modification
- Conduct immediate medication review to identify drugs with anticholinergic effects 2
- Eliminate or substitute offending medications where clinically appropriate 6, 2
- This is the single most effective intervention when medications are the cause 2, 3
Step 2: Non-Pharmacological Interventions (First-Line)
- Implement good oral hygiene practices including regular brushing and flossing 2
- Use saliva substitutes containing xylitol (such as Biotene products) 6, 2
- Ensure adequate hydration 2, 3
- Reduce alcohol and caffeine intake 2
- Encourage sipping water frequently throughout the day 8
Step 3: Pharmacological Treatment (When Non-Pharmacological Measures Insufficient)
Pilocarpine (cholinergic agonist) is the FDA-approved prescription medication for xerostomia 9, 6, 3
Pilocarpine Dosing:
- For radiation-induced xerostomia: Start 5 mg three times daily; may increase to 10 mg three times daily based on response and tolerability 9
- For Sjögren's syndrome: 5 mg four times daily (20 mg/day) showed statistically significant improvement in global dry mouth symptoms after 6 weeks 9
- Lower doses (2.5 mg three times daily) were comparable to placebo and should not be used 9
Pilocarpine Efficacy:
- Demonstrated statistically significant global improvement in dry mouth symptoms including severity of dry mouth, mouth discomfort, ability to speak without water, ability to sleep without drinking water, ability to swallow food without drinking, and decreased use of saliva substitutes 9
- Greatest improvement noted in patients with no measurable salivary flow at baseline 9
Common Adverse Effects (Dose-Related):
- Sweating (most common cause of discontinuation: 12% at 10 mg three times daily) 9
- Nausea, rhinitis, diarrhea, chills, flushing, urinary frequency, dizziness, and asthenia 9
Special Considerations:
- In elderly females, mean Cmax and AUC are approximately twice that of elderly males, requiring careful dose titration 9
- In patients with mild to moderate hepatic impairment, exposure doubles and peak levels increase by 30%, necessitating dose reduction 9
- No significant pharmacokinetic differences in renal insufficiency 9
Step 4: Preventive Dental Care
- Refer to dentist for ongoing preventive care focused on caries prevention 6, 2
- Fluoride treatments are particularly important given increased caries risk 1, 6
- Regular dental monitoring to detect early complications 8
Critical Pitfalls to Avoid
- Do not assume xerostomia is a normal part of aging - it indicates an underlying cause requiring investigation 3, 5
- Do not ignore medication-induced xerostomia - this is the most modifiable cause and should be addressed first 2, 3
- Do not delay dental referral - chronic xerostomia significantly increases risk of dental caries and periodontal disease 6, 2
- Do not use pilocarpine at subtherapeutic doses (2.5 mg three times daily is ineffective) 9
- Do not overlook systemic diseases like Sjögren's syndrome or diabetes that may require specific management 6, 3
When to Consider Underlying Dysphagia
If dry mouth is accompanied by choking episodes, difficulty swallowing, or unexplained weight loss, consider that reduced salivary clearance from dysphagia may be contributing to symptoms rather than true hyposalivation 1, 7