Excessive drooling, called sialorrhea, is a common symptom of Parkinson’s and can cause awkwardness in social situations. It ranges from mild wetting of the pillow during sleep to embarrassing outpourings of saliva during unguarded moments. For example, this can happen when the head is down, the mouth is held open involuntarily (as happens in advanced PD) or when a person is engaged in an activity and is distracted from the need to swallow automatically.
Drooling, along with speech and swallowing issues, is included among non-movement symptoms even though the root cause is motor: decreased coordination, slowness of movement (bradykinesia) and rigidity of the muscles of the mouth and throat.
Parkinson’s causes a reduction in automatic actions, including swallowing, creating an inability to manage the flow of saliva in and around the mouth. In PD, usually the amount of saliva your body produces is normal, but swallowing difficulties – swallowing less often or not completely – lead to saliva pooling in the mouth.
When severe, drooling is an indicator of more serious difficulty with swallowing (also known as dysphagia), which can cause the person to choke on food and liquids and can even lead to aspiration pneumonia.
If you are having problems with drooling, you might consider an appointment with a speech-language pathologist. These professionals can perform a swallow test to diagnose any difficulties and can also give you some strategies to help with drooling.
One trick is to suck on hard candy or chew gum, preferably sugarless. Candy and gum activate the jaw and the automatic swallowing reflex and can help clear saliva, providing temporary relief from drooling.
Another tactic is to wear a sweatband on your wrist. This can be used to discretely wipe the mouth as necessary and is a relatively inconspicuous accessory.
If these lifestyle strategies are not effective, adjusting anti-PD medications may make it easier to swallow. There are also some other prescription medication options:
- Glycopyrrolate and other oral anticholinergic medications (trihexyphenidyl, benztropine, hycosamine): Oral anticholinergic medications, as a class, decrease the production of saliva. Usually this is perceived as a side effect (dry mouth), but in this case it is an advantage. Other anticholinergic side effects may be seen, including drowsiness, confusion, vomiting, dizziness, blurred vision, constipation, flushing, headache and urinary retention. Anticholinergics can also have mental side effects, so their use should be carefully considered.
- Scopolamine patch: This patch offers anticholinergic medicine that slows production of saliva as it is absorbed into the entire bloodstream. The side effects are similar to those seen with use of oral anticholinergic medications.
- 1% atropine eye drops (an anticholinergic): This treatment is given as 1-2 drops under the tongue per day to dry the mouth. Systemic side effects are much less likely with this local treatment.
- Botulinum toxin A: Botulinum toxin weakens muscles. Botulinum toxin A (Botox) is sometimes used to decrease saliva production for people who have issues with drooling; botulinum toxin B (Myobloc) is used to treat dystonia. Injection of botulinum toxin A into the salivary glands of the cheek and jaw decreases production of saliva without side effects, except for thickening of oral mucus secretion. Botox is not always effective, but when it works the benefit can last for several months before it wears off and re-injection is necessary. Botulinum toxin A can be an effective treatment for severe drooling, although pills, the patch and mouth drops should be tried first in the interest of cost saving. Botulinum toxin should probably be avoided when oral secretions are already deep and thick. Botulinum toxin B causes dry mouth when used for dystonia, but it is not approved by the FDA for drooling.