If you have Parkinson's disease you have probably learned to carry around a handkerchief in your pocket so that you can periodically wipe up the spit that seems to regularly leak out of your mouth. Survey studies have recorded the presence of excess saliva or drooling in 70 to 78% of patients with PD. Men drool more than women and it appears to be more embarrassing for men than for women.
Why All the Excess Saliva in Parkinson's Disease?
Scientists have found that the problem is not one of over-production but one of inefficient and infrequent swallowing. In fact, saliva production in PD is typically diminished over normal levels. Persons with PD simply do not swallow as much as other people.
So What Can Be Done?
There are several drug treatments available. Potent drugs knonw as anticholinergics, such as trihexyphenidyl hydrochloride and benzatropine mesilate, are prescribed in an attempt to “dry up” the excess saliva. But this class of drugs often creates troublesome side effects such as constipation, urinary retention, memory impairment, confusion, and even hallucinations, particularly in elderly individuals. Another possibility is to take a drop of 1% atropine ophthalmic solution under the tongue twice daily but this has been tried in only a handful of patients. Injections of botulinum toxin A have also been used to try to eradicate excessive saliva in PD. Although this drug is effective for some people with PD, side effects are again an issue including an excessively dry mouth and dysphagia or trouble swallowing food.
Merello M. Sialorrhoea and drooling in patients with Parkinson's disease: epidemiology and management. Drugs & Aging. 25(12):1007-1019, 2008.