With the recent questions regarding the effectiveness of newer atypical antipsychotic medications in treating schizophrenia, clozapine continues to remain the gold standard for treatment-refractory schizophrenia. However, treatment with clozapine continues to be limited by its many side effects. The second most common side effect, occurring in 31% of clozapine treated patients, is hypersalivation or sialorrhea. Sialorrhea can be profoundly stigmatizing and functionally disabling in certain patients, and may increase discontinuation rates in this high-risk patient population. Several studies have evaluated the efficacy of anticholinergic agents mainly in small, uncontrolled studies or anecdotal reports and are often complicated by difficulties in medication administration and systemic side effects. Open label and case series studies have demonstrated promising results with ipratropium bromide (IPB) treatment of clozapine-induced hypersalivation, acting on anticholinergic receptors with minimal systemic absorption. However, no randomized controlled trials have evaluated IPB in the treatment of this problematic side effect.The primary goals of this study is to determine the efficacy of ipratropium bromide in reducing clozapine-induced hypersalivation, as per the Toronto Nocturnal Hypersalivation Scale, which is a modified hypersalivation scale incorporating the Drooling Severity Scale and the Nocturnal Hypersalivation Rating Scale, and reduced measurements on visual analogue scales for hypersalivation distress and severity. Our hypothesis that Ipratropium bromide use at bedtime will result in a significant reduction in nocturnal clozapine-induced hypersalivation as measured by the Toronto Nocturnal Hypersalivation Scale (TNHS) through its local anticholinergic activity.