Guanfacine for Clozapine-Induced Sialorrhea in Treatment-Resistant Schizophrenia: A Case Report

Clozapine is the gold-standard treatment for treatment-resistant schizophrenia (TRS) but is often limited by adverse effects. Sialorrhea occurs in 30–80% of clozapine users and may cause skin irritation, infections, poor sleep, social isolation, and reduced adherence. First-line treatments include atropine, tropicamide, amitriptyline, and amisulpride. We report the use of guanfacine in a TRS patient with refractory clozapine-induced sialorrhea (CIS). We present a 34-year-old woman with TRS who was successfully managed on clozapine (350 mg/day). However, a few months into therapy, she developed debilitating diurnal and nocturnal sialorrhea. Standard treatments, including sublingual atropine, hyoscine, amitriptyline, and adjunctive amisulpride, failed to alleviate her drooling. Consequently, oral guanfacine at a dose of 1 mg/day (an α2-adrenergic agonist) was initiated. Remarkably, within just 7 days, her sialorrhea completely resolved without any side effects or changes in vital signs. The patient's quality of life and social functioning improved significantly as drooling stopped. She maintained adherence to clozapine, which allowed further improvement in psychotic symptoms. Low-dose guanfacine may be an alternative treatment approach in CIS. The α2-agonistic effect of guanfacine may have been effective in the treatment of sialorrhea. Case-control studies on the efficacy of guanfacine in CIS are needed.