What are the causes and treatments of excessive saliva production?

Causes and Treatment of Excessive Saliva Production

Primary Causes

Excessive saliva is most commonly caused by impaired clearance due to dysphagia rather than true overproduction, particularly in neurological conditions, though certain medications—especially cholinergic agents—can genuinely increase salivary secretion. 1

Neurological and Swallowing Disorders

• Dysphagia is the leading cause of apparent hypersalivation, resulting from reduced clearance rather than increased production in conditions like Parkinson's disease, cerebral palsy, and post-stroke states 1, 2, 3
• Neurogenic dysphagia occurs in 25-65% of acute stroke patients, with sialorrhea being a common manifestation 3
• The distinction between true hypersalivation and impaired clearance is critical for appropriate treatment selection 1

Medication-Induced Causes

• Acetylcholinesterase inhibitors (used for Alzheimer's disease) commonly cause increased saliva production through cholinergic overstimulation 1
• Atypical antipsychotics including clozapine, risperidone, quetiapine, and aripiprazole are frequent culprits 4, 5, 6
• Sedatives such as benzodiazepines and neuroleptics carry dose-dependent risk 4
• Other medications include pilocarpine, bethanecol, lithium, and nitrazepam 2, 4

Gastrointestinal Causes

• Gastroesophageal reflux disease (GERD) manifests as "water brash"—a subtle but important cause of increased salivary flow 2
• Esophageal obstruction from foreign bodies, cancer, or strictures 2
• Achalasia and megaesophagus (including Chagas disease from Trypanosoma cruzi) 2

Other Medical Conditions

• Oral and gum diseases, particularly periodontal disease 1
• Infections of the oropharynx 2
• Heavy metal poisoning, Wilson disease, Angelman syndrome 2
• Chronic kidney disease affecting salivary composition 1

Physiological Factors

• Acidic food consumption stimulates saliva production more than sugar or carbohydrate-rich foods 7
• Physical and psychological stressors can impact salivary flow 7
• Mouth piercings can cause increased salivary flow as a complication 7

Treatment Approach

Step 1: Identify and Address Underlying Cause

• Determine if true hypersalivation versus impaired clearance through clinical assessment of swallowing function 1, 2
• Review medication list and consider dose reduction or discontinuation of causative agents when feasible 6
• Treat underlying conditions such as GERD, oral infections, or periodontal disease 2

Step 2: Non-Pharmacological Management

• Increase swallowing frequency with chewing gum as first-line non-drug intervention 6
• For dysphagia-related sialorrhea, implement chin-tuck posture during swallowing, which protects airways and prevents laryngeal penetration 7
• Head rotation maneuvers for hypertonicity or premature upper esophageal sphincter closure 7
• Patient education regarding positioning and oral hygiene 6

Step 3: Pharmacological Treatment

For medication-induced sialorrhea:

• Anticholinergic agents are first-line pharmacological treatment after non-drug measures fail 6

• Glycopyrrolate oral solution is FDA-approved for chronic severe drooling in patients aged 3-16 years with neurological conditions 8

  • Start at 0.02 mg/kg three times daily, titrate every 5-7 days up to maximum 0.1 mg/kg three times daily 8
  • Must be dosed at least one hour before or two hours after meals due to significant food effects reducing bioavailability by 74-78% 8
  • Monitor for constipation within 4-5 days of initiation or dose increase 8
  • Contraindicated in glaucoma, paralytic ileus, myasthenia gravis, and with solid potassium chloride formulations 8
  • Use with caution in renal impairment as drug is largely renally eliminated 8

• Alternative anticholinergics include atropine and scopolamine 6

• Alpha-2-adrenergic agonists (clonidine) as second-line option 6

• Dopamine antagonists (amisulpride) have shown efficacy 6

Step 4: Advanced Interventions

• Botulinum toxin injections into major salivary glands (parotid, submandibular) are highly effective for refractory cases 7, 5, 3
• This is particularly useful for neurogenic sialorrhea in Parkinson's disease, ALS, and post-stroke patients 5, 3
• Injections into the cricopharyngeus muscle may also be beneficial 3

Critical Clinical Considerations

Complications to Monitor

• Aspiration pneumonia is the most serious complication, especially in patients with diminished sensation of salivary flow and hypopharyngeal retention 2, 3
• Mortality rates of 20-24% occur in post-stroke patients with dysphagia requiring tube feeding 3
• Social isolation and decreased quality of life from drooling 2, 3
• Perioral skin maceration and irritation 3

Special Populations

• Pediatric patients: Glycopyrrolate has not been studied in children under 3 years of age 8
• Renal impairment: Use glycopyrrolate with caution due to renal elimination 8
• Pregnancy/lactation: No data available on glycopyrrolate in human milk; consider risk-benefit 8

Common Pitfalls

• Failing to distinguish between true hypersalivation and impaired clearance leads to inappropriate treatment 1, 2
• Not recognizing GERD as a subtle cause of increased salivation 2
• Overlooking medication review as initial intervention 6
• Administering glycopyrrolate with meals, which dramatically reduces efficacy 8
• Not monitoring for constipation after anticholinergic initiation 8