What is the recommended approach to evaluate and treat xerostomia?

Evaluation and Management of Xerostomia

The evaluation of xerostomia should begin by identifying the underlying cause through medication review and assessment for systemic diseases, followed by objective measurement of salivary flow, with management prioritizing cause-directed interventions (medication adjustment, IMRT for radiation prevention) over symptomatic treatment with salivary stimulants or substitutes. 1, 2

Initial Evaluation

History and Examination

• Conduct a detailed medication review focusing on anticholinergic agents (tricyclic antidepressants, antihistamines, cyclobenzaprine), beta-blockers, SSRIs, opioids, and centrally acting antihypertensives, as these are the most common causes 3, 4
• Screen for systemic diseases including Sjögren's syndrome (affects 0.4% of population, 20:1 female predominance), diabetes, rheumatoid arthritis, and sicca syndrome 3, 5
• Assess for radiation therapy history to the head and neck region, as this causes salivary gland dysfunction and dramatically increases dental caries risk 6
• Measure objective salivary flow rates before initiating treatment, as subjective sensation may not correlate with actual output 3, 7
• Rule out mimicking conditions such as candidiasis, burning mouth syndrome, and dysphagia, which can present similarly 3

Comprehensive Oral Assessment

• Perform complete oral and head and neck examination with radiographs of all teeth to assess for radiation-related caries (can appear within 3 months post-RT), periodontal disease, and periapical pathology 6
• Evaluate risk for dental caries and periodontal disease, as xerostomia dramatically increases these risks through demineralization and microbial changes 6, 2

Prevention Strategies (Radiation-Induced Xerostomia)

Primary Prevention

Use IMRT (Intensity-Modulated Radiation Therapy) preferentially over conventional radiotherapy to spare major salivary glands, reducing mean parotid dose from 62 Gy to 32 Gy 6, 1

• IMRT reduces clinician-rated severe xerostomia at 1 year from 82.1% to 39.3% (P = 0.001) 6, 1
• Grade 2 or worse xerostomia occurs in 38% with IMRT versus 74% with conventional RT (P = 0.003) 6, 1

Pharmacologic Prevention During Radiation

Administer amifostine 200 mg/m² IV over 15 minutes, 30 minutes before each radiation fraction for patients receiving definitive head and neck radiotherapy 1

• Reduces grade 2 or higher acute xerostomia from 78% to 51% (P < 0.0001) 1
• Reduces chronic xerostomia at 1 year from 57% to 34% (P = 0.002) 1
• Monitor blood pressure during infusion as hypotension can occur 1

Critical caveat: Amifostine is a preventive agent used during radiation therapy, not a treatment for established xerostomia 1

Treatment of Established Xerostomia

First-Line: Address Underlying Cause

Review and modify medications with anticholinergic effects in collaboration with prescribing physicians, as this is the most common reversible cause 3, 4

• Elderly patients face substantially higher risk due to polypharmacy combined with age-related decline in salivary flow 3

Optimize hydration by increasing water intake and limiting caffeine 8

Second-Line: Symptomatic Management Based on Residual Function

For Patients WITH Residual Salivary Function

Use salivary stimulants as first-line symptomatic therapy 4

• Pilocarpine is the traditional option, though cevimeline may have better tolerance profile (though less widely available) 1
• Sugar-free chewing gum or xylitol products provide mechanical stimulation and subjective relief 1, 2
• Sugar-free acidic candies or lozenges can stimulate residual function 1

For Patients WITHOUT Measurable Salivary Flow

Use saliva substitutes as the preferred therapeutic approach 1, 4

• Ideal preparations should have neutral pH and contain fluoride and electrolytes to mimic natural saliva 1
• Products like Biotene can provide symptomatic relief 9

Dietary and Lifestyle Modifications

Implement dietary changes by avoiding crunchy, spicy, acidic, or hot foods/drinks that exacerbate discomfort 8

Dental Management and Prevention of Complications

During Cancer Therapy

Manage xerostomia actively while preventing trismus and evaluating for oral candidiasis 6

• Maintain range of motion with tongue blades, gentle stretching, and custom mouth opening devices 6

Post-Treatment Surveillance

Schedule dental recall visits at least every 6 months, or more frequently for patients with xerostomia or new caries lesions 6

Implement aggressive caries prevention with topical fluoride interventions, as radiation-related caries can appear within 3 months of RT 6, 2

Monitor for and treat oral candidiasis as clinically indicated 6

Specialist Referral Criteria

Refer to dental specialist for severe xerostomia to prevent dental caries and receive oral hygiene counseling 8

Immediate dental referral for complicated oral conditions, infections, or signs of oral candidiasis beyond primary care scope 8

Refer to rheumatology when clinical features suggest Sjögren's syndrome for specialized diagnostic workup 8

Automatic referral of head and neck cancer survivors to dental professionals experienced in oncology care due to elevated risk of radiation-induced complications 8

Common Pitfalls to Avoid

• Do not delay treatment while waiting for complete diagnostic workup; initiate symptomatic management early 2
• Do not use salivary stimulants in patients without residual function; they will be ineffective and saliva substitutes should be used instead 1, 4
• Do not overlook medication review as the most common and reversible cause 3, 4
• Do not assume subjective symptoms correlate with objective salivary flow; measure flow rates before treatment decisions 3, 7
• Do not delay dental referral when severe xerostomia is causing functional impairment in eating, speaking, or denture tolerance 8