Comparing the Impact of Atropine Drops and Amitriptyline Tablets in Treatment of Clozapine-Induced Sialorrhea: A Randomized Double-Blind Placebo Controlled Clinical Trial

Clozapine is an atypical antipsychotic employed to treat patients with psychotic disorders. It is associated with sialorrhea as a problematic adverse effect in 30-80% of cases. Various medications such as atropine and amitriptyline have been suggested for its treatment. We aimed to compare the effects of atropine drops and amitriptyline tablets in the treatment of clozapine-induced sialorrhea. The present double-blind, randomized clinical trial aimed to evaluate the effect of atropine drops and amitriptyline tablets in reducing clozapine-induced sialorrhea in patients with psychotic disorders. Forty-six patients were treated for 4 weeks in two groups: group “A”(atropine drops and placebo tablets) and group “B” (amitriptyline tablets and placebo drops). Toronto Nocturnal Hypersalivation Scale (TNHS) and Clinical Global Impression (CGI) rating scale were used for measurement of the severity and frequency of sialorrhea and global symptom severity and treatment response, respectively. Kolmogorov–Smirnov, Chi-square and Fisher's exact tests were used for statistical analyses. Demographic information of the two groups had no significant difference (P>0.05). There was no patient with adverse effects that interfered with the study. Mean TNHS and Meier scores in groups “A” and “B” were 3.48±0.21 vs.3.24±0.18, and 1.9±0.07 vs.1.86±0.07, respectively, and the difference was not statistically significant (P=0.35 vs. P=0.67). In patients with clozapine-induced sialorrhea, 1% atropine drops (1.7 mg sublingual drops daily) can be just as effective as amitriptyline tablets (29.08 mg daily, oral) in controlling sialorrhea.