Pilocarpine Treatment of Xerostomia Induced by Psychoactive Medications

To the Editor: Dry mouth (xerostomia) is a frequent complication of psychoactive medications with antimuscarinic and anticholinergic side effects. The lack of saliva is annoying to patients, impairs their ability to masticate and digest food, and is a potential source of dental morbidity, including increased risk for caries and oral infection. Pilocarpine is a cholinergic muscarinic agonist. It has been used to treat xerostomia induced in cancer patients by head and neck radiotherapy (1). It has recently been found to be effective in doses of 20 mg/day in a randomized, placebo-controlled dose-adjustment study in the treatment of dry mouth and dry eyes in patients with Sjogren’s syndrome (2). It has been used to treat dry mouth as a complication of opioid treatment (3). Toxicity has been infrequently reported (4). However, it is contraindicated in patients with angle-closure glaucoma.

We have empirically used pilocarpine in doses of 10–30 mg/day, divided into dosing of two or three times a day. We have used it with our acute psychiatric inpatients, ages 20–69, who complained of dry mouth after they had been started on psychoactive medication. These included atypical antipsychotic agents, particularly clozapine and olanzapine; anticholinergic agents, primarily benztropine; and antidepressants, particularly tricyclic antidepressants and mirtazapine. Substantial relief of dry mouth was achieved in most patients. Side effects were mainly sweating and increased urination. We did not observe any adverse impact on psychiatric symptoms. The patients were generally pleased that their dry mouth symptoms responded rapidly, usually within 1 day, to pilocarpine treatment. Further investigation into the use of pilocarpine for the treatment of xerostomia induced by psychoactive medication seems warranted.