What medications are used to treat dry mouth (xerostomia)?

Medications to Treat Dry Mouth (Xerostomia)

Treatment Algorithm Based on Salivary Gland Function

The treatment of dry mouth should be guided by baseline salivary gland function measurement, with a stepwise approach starting with non-pharmacological stimulation for mild dysfunction, advancing to pharmacological muscarinic agonists for moderate dysfunction, and using saliva substitutes for severe dysfunction with no salivary output. 1

Step 1: Assess Baseline Salivary Function

• Measure whole salivary flow rates before initiating treatment, as subjective feelings of dryness may not correlate with objective measurements 1, 2
• Rule out conditions unrelated to salivary dysfunction such as candidiasis, burning mouth syndrome, or underlying Sjögren's syndrome 1, 3

Step 2: Non-Pharmacological Stimulation (Mild Dysfunction)

• Use gustatory stimulants including sugar-free acidic candies, lozenges, or xylitol as first-line therapy for patients with measurable salivary flow 1, 2
• Employ mechanical stimulants such as sugar-free chewing gum to stimulate residual gland function 1, 2
• Optimize hydration by increasing water intake throughout the day and limiting caffeine consumption 2, 3
• No evidence suggests one non-pharmacological intervention is superior to another, though all provide some degree of symptomatic relief 1, 2

Step 3: Pharmacological Stimulation (Moderate Dysfunction)

For patients with moderate glandular dysfunction who fail non-pharmacological measures, muscarinic agonists (pilocarpine or cevimeline) should be offered as second-line therapy. 1

Pilocarpine (FDA-Approved)

• Pilocarpine 5 mg orally three to four times daily is the standard dosing regimen, with FDA approval for treating dry mouth from radiation therapy and Sjögren's syndrome 4
• Doses up to 10 mg three times daily may provide additional benefit in some patients, though side effects increase with higher doses 4, 5
• Significant improvements in salivary flow occur within the first dose and are maintained throughout treatment, with 2- to 10-fold increases in mean salivary flow rates compared to placebo 4, 6
• Clinical trials demonstrate 54% of patients experience symptom improvement versus 25% with placebo 6, 5
• Peak therapeutic effects may require continuous treatment for more than 8 weeks 5

Cevimeline

• Cevimeline is another FDA-approved muscarinic agonist with similar efficacy to pilocarpine but may have a better tolerance profile with fewer systemic side effects 1
• The evidence comparing cevimeline directly to pilocarpine is limited to retrospective studies focused on safety rather than efficacy 1

Important Side Effects and Monitoring

• The most common adverse effects are sweating (occurring in over 40% of patients), nausea, rhinitis, diarrhea, chills, flushing, urinary frequency, dizziness, and asthenia 1, 4
• Sweating is the most common reason for treatment discontinuation, occurring in ≤1% at 5 mg three times daily but 12% at 10 mg three times daily 4
• Other cholinergic side effects include bronchoconstriction, which requires careful monitoring especially in elderly patients 2, 7
• Patients with hepatic impairment experience 30% decreased clearance and doubled drug exposure, requiring dose adjustment 4

Step 4: Saliva Substitution (Severe Dysfunction/No Salivary Output)

• Saliva substitutes with neutral pH containing fluoride and electrolytes to mimic natural saliva should be the preferred approach for patients with no measurable salivary output 1, 2
• Available formulations include oral sprays, gels, and rinses that can be applied as needed throughout the day 1, 2, 3
• These products provide temporary symptomatic relief but do not stimulate natural saliva production 2, 8

Essential Supportive Care

Dental Referral

• All patients with moderate to severe dry mouth require dental referral to ensure adequate oral hygiene and protect against dental caries, which is a significant risk with chronic xerostomia 2, 3
• Regular dental monitoring is essential as reduced saliva flow increases risk of dental caries, oral infections, and periodontal disease 3, 8

Dietary Modifications

• Avoid crunchy, spicy, acidic, or hot foods that exacerbate oral discomfort 2, 3
• Use specialized toothpastes and rinses designed for dry mouth that contain fluoride for additional protection 2

Common Pitfalls to Avoid

• Do not prescribe muscarinic agonists to patients with no measurable salivary flow, as they require residual gland function to be effective 1
• Avoid starting with high doses of pilocarpine (10 mg); begin with 5 mg three times daily and titrate only if needed, as side effects increase substantially with higher doses 4, 5
• Do not overlook medication review, as many commonly prescribed drugs (anticholinergics, antidepressants, antihistamines, beta-blockers) contribute to xerostomia 3, 7
• Elderly patients are at substantially higher risk due to polypharmacy and age-related decline in salivary flow, requiring more cautious monitoring 3, 7