What is the cause of hypersalivation (excessive salivation)?

From the Guidelines

For patients with hypersalivation, botulinum toxin (BT) therapy to salivary glands is suggested for those who have an inadequate response or are intolerant of the side effects of anticholinergic therapy, as per the latest guidelines from 2023 1. Hypersalivation can be managed through various approaches, but the most recent and highest quality study recommends BT therapy for patients with neuromuscular weakness who do not respond to anticholinergic therapy. Some key points to consider when managing hypersalivation include:

• Identifying and treating underlying causes such as medication side effects, neurological conditions, or oral infections
• Using anticholinergic medications as first-line treatments, but being aware of potential side effects such as dry mouth, blurred vision, or constipation
• Considering BT therapy for patients who do not respond to anticholinergic therapy, with doses varying depending on individual studies, as noted in the guidelines 1
• Supportive measures such as using absorbent pads, maintaining good oral hygiene, and practicing swallowing techniques can also be beneficial It is essential to weigh the benefits and risks of each treatment option and consider local expertise when deciding between BT therapy and other treatments like radiation therapy, as suggested by the guidelines 1.

From the FDA Drug Label

Glycopyrrolate is a competitive inhibitor of acetylcholine receptors that are located on certain peripheral tissues, including salivary glands. Glycopyrrolate indirectly reduces the rate of salivation by preventing the stimulation of these receptors. Glycopyrrolate inhibits the action of acetylcholine on salivary glands thereby reducing the extent of salivation.

Glycopyrrolate oral solution is used to treat chronic severe drooling in patients aged 3-16 years with neurologic conditions associated with problem drooling. The drug reduces salivation by inhibiting the action of acetylcholine on salivary glands.

• Hypersalivation is the opposite of the drug's intended effect, which is to reduce salivation.
• The FDA label does not provide information on the treatment of hypersalivation with glycopyrrolate. However, given glycopyrrolate's mechanism of action, it is likely that the drug would be effective in treating hypersalivation by reducing salivation.
• Key points:
  • Glycopyrrolate reduces salivation by inhibiting acetylcholine receptors on salivary glands.
  • The drug is used to treat chronic severe drooling in patients with neurologic conditions.
  • Glycopyrrolate may be effective in treating hypersalivation due to its mechanism of action 2.

From the Research

Definition and Causes of Hypersalivation

• Hypersalivation, also known as sialorrhea or excessive salivation, is a common problem in neurologically impaired children and adults with certain conditions such as Parkinson's disease or those who have had a stroke 3.
• It is most commonly caused by poor oral and facial muscle control, and contributing factors may include hypersecretion of saliva, dental malocclusion, postural problems, and an inability to recognize salivary spill 3.
• Hypersalivation can also be caused by certain medications, such as clozapine, which is used to treat psychiatric disorders 4, 5.

Treatment Options for Hypersalivation

• Treatment of hypersalivation is best managed by a clinical team that includes primary health care providers, speech pathologists, occupational therapists, dentists, orthodontists, neurologists, and otolaryngologists 3.
• Treatment options range from conservative measures such as observation, postural changes, and biofeedback to more aggressive measures such as medication, radiation, and surgical therapy 3.
• Anticholinergic medications, such as glycopyrrolate and scopolamine, are effective in reducing drooling, but their use may be limited by side effects 3, 6, 7.
• The injection of botulinum toxin into the parotid and submandibular glands is a safe and effective treatment for hypersalivation, with effects lasting several months 3, 6, 4, 5.
• Surgical intervention, including salivary gland excision, salivary duct ligation, and duct rerouting, provides a more permanent treatment for significant hypersalivation, but is typically reserved for isolated cases 3, 6, 7.

Diagnostic Tools and Multidisciplinary Approach

• Diagnostic tools such as fiberoptic endoscopic evaluation of swallowing and videofluoroscopic swallowing studies generate important data on therapy selection and control 7.
• Transnasal swallowing endoscopy allows for the evaluation of dysphagia with limited risks and can help judge the effectiveness of therapy options 6.
• A multidisciplinary approach to diagnosis and treatment is recommended, involving a team of healthcare professionals to address the complex needs of patients with hypersalivation 3, 6, 7.