Pilocarpine toxicity and the treatment of xerostomia

Pilocarpine has been used as an ophthalmologic agent for decades; however, toxicity rarely has been reported in the medical literature. Oral pilocarpine tablets, as well as another muscarinic agent (cevimeline), have recently been approved for the treatment of dry mouth (xerostomia). We report a case of unintentional overdose of oral pilocarpine tablets that resulted in bradycardia, mild hypotension, and muscarinic symptoms in a patient with Sjogren's syndrome. The patient's symptoms were relieved with 0.5 mg intravenous atropine and she recovered uneventfully. The case is unique in that it is the first reported ingestion of oral pilocarpine tablets and the first dosing error reported for this indication. In addition, this case underscores the importance of communication between physician and patient and the resulting toxicity related to miscommunication.