Clozapine是治療思覺失調症的藥物，但在臨床使用中，常伴隨一系列不良反應，如口水過多（clozapine-induced sialorrhea, CIS）、心跳加快、發燒，甚至可能引發吸入性肺炎等併發症。同時，當出現CIS時，clozapine的劑量調整速度需謹慎，而延宕治療病情。CIS的非藥物治療如白天咀嚼口香糖增加吞嚥，或是夜間睡覺時墊高枕頭或側躺以減少嗆咳，皆非直接減少唾液分泌，且當患者正處於急性期時，也難以配合；藥物治療中，各醫院存在不同的選擇，缺乏共識。作者根據實證的五大步驟進行，以臨床問題形成PICO，以系統性回顧法於PubMed、Cochrane Library、Embase、華藝線上圖書館之資料庫做搜尋，使用關鍵字 “clozapine” 、“sialorrhea“atropine” 之MeSH term及同義字，並與安慰劑或其他藥物做比較，搜尋2015年至2025 年2月15日以前的中英文文獻。篩選後共有3篇符合，並以Oxford Centre for Evidence-Based Medicine (CEBM) 隨機分派研究之評讀工具分析文章品質，建議等級為grade 2，使用舌下滴劑atropine眼藥水治療可明顯改善CIS症狀及夜間睡眠品質。將此結果應用於臨床實際案例，結果確認早晚使用atropine眼藥水滴於舌下可快速顯著改善CIS，藥物給藥頻率也由一天兩次調整至睡前一次，最終患者精神症狀穩定，順利出院。因此， 對於使用clozapine治療而引起口水過多的患者，建議使用1% atropine眼藥水兩滴滴於舌下改善CIS，以提升患者的服藥遵從性和生活與睡眠品質。

Clozapine is an antipsychotic medication indicated for treatment-resistant schizophrenia; however,its clinical use is frequently associated with a range of adverse effects, including clozapine-induced sialorrhea (CIS), tachycardia, fever, and in severe cases, aspiration pneumonia. Furthermore, manage-ment of CIS poses a particular challenge, as rapid dose adjustments may exacerbate psychiatric insta-bility and delay therapeutic progress. Non-pharmacological treatments for CIS—such as chewing gum during the day to stimulate swallowing, or positional strategies at night to reduce choking—do not di-rectly reduce salivary secretion and may be difficult for patients to adhere to, especially during acute psychotic episodes. Currently, no standardized pharmacological treatment protocol for CIS exists, and treatment approaches vary among institutions. Following the five steps of the evidence-based practice framework, this study formulated a PICO question and conducted a systematic literature review using databases including PubMed, Cochrane Library, Embase, and Airiti Library. The search employed keywords and MeSH terms including “clozapine,” “sialorrhea,” and “atropine,” and included studies comparing atropine to placebo or other treatments published in English or Chinese before February 15, 2025. After screening, three randomized controlled trials met the inclusion criteria. Study quality was appraised using the Oxford Centre for Evidence-Based Medicine (CEBM) critical appraisal tool, with all studies receiving a grade 2 recommendation level. Findings indicate that sublingual adminis-tration of 1% atropine ophthalmic solution significantly improves CIS symptoms and enhances sleep quality. Application of this intervention in a clinical case confirmed its efficacy: twice-daily sublin-gual atropine drops produced rapid symptom relief, which allowed for tapering to once-daily bedtime administration. The patient subsequently achieved psychiatric stabilization and was successfully dis-charged. Based on current evidence, the sublingual use of two drops of 1% atropine ophthalmic solu-tion is recommended for managing CIS. This treatment may improve medication adherence, as well as overall patient quality of life and sleep during clozapine therapy.