{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,22]],"date-time":"2026-08-22T09:31:28Z","timestamp":1787391088057,"version":"build-2736575974"},"reference-count":18,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,7,4]],"date-time":"2026-07-04T00:00:00Z","timestamp":1783123200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmacy"],"abstract":"<jats:p>Clozapine-induced hypersalivation (CIH) affects 30\u201380% of patients on clozapine and is a major contributor of non-adherence. Current managements, largely based on systemic anticholinergics, can worsen other clozapine-related side effects. Here sublingual tropicamide 1% eye drops can be a low-cost alternative worth evaluating. We report a case series of seven patients with schizophrenia treated with sublingual tropicamide 1% ophthalmic solution (4\u20138 drops\/day) for CIH. Treatment response was assessed by patient-reported percentage reduction in salivation. All seven patients reported improvement (25\u201380%). One patient reported a transient bitter taste; no systemic anticholinergic effects occurred. Sublingual tropicamide was associated with patient-reported improvement in CIH and was well tolerated in this small, uncontrolled series. Its short duration of action and local administration may offer practical advantages over systemic anticholinergics, though the mechanism remains unproven. Randomised trials with validated outcome measures are needed to establish its efficacy and safety.<\/jats:p>","DOI":"10.3390\/pharmacy14040101","type":"journal-article","created":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T08:05:38Z","timestamp":1783325138000},"page":"101","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Sublingual Tropicamide Eye Drops for the Management of Clozapine-Induced Hypersalivation: A Case Series of Seven Patients"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5554-2216","authenticated-orcid":false,"given":"Seshadri Sekhar","family":"Chatterjee","sequence":"first","affiliation":[{"name":"Department of Psychiatry, Central Queensland Hospital and Health Service (CQHHS), Rockhampton, QLD 4700, Australia"},{"name":"School of Medicine, The University of Queensland, Rockhampton, QLD 4700, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7329-8264","authenticated-orcid":false,"given":"Soumitra","family":"Das","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, Western Health, Melbourne, VIC 3021, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adesh","family":"Agrawal","sequence":"additional","affiliation":[{"name":"Department of Psychiatry, All India Institute of Medical Sciences (AIIMS), Deoghar 814152, Jharkhand, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"MY20096AH1C","DOI":"10.4088\/JCP.MY20096AH1C","article-title":"Treatment-Resistant Schizophrenia: Definition, Predictors, and Therapy Options","volume":"82","author":"Correll","year":"2021","journal-title":"J. Clin. Psychiatry"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"662","DOI":"10.1345\/aph.19259","article-title":"Clozapine-induced hypersalivation","volume":"34","author":"Davydov","year":"2000","journal-title":"Ann. Pharmacother."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1097\/JCP.0000000000001917","article-title":"Clozapine-Associated Sialorrhea: A Literature Review","volume":"44","author":"Atalay","year":"2024","journal-title":"J. Clin. Psychopharmacol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"458","DOI":"10.1093\/schbul\/sbae065","article-title":"Clozapine Efficacy and Adverse Drug Reactions Among a Nationwide Study of 1021 Australians Prescribed Clozapine: The ClozaGene Study","volume":"51","author":"Lind","year":"2025","journal-title":"Schizophr. Bull."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"377","DOI":"10.1177\/070674370705200607","article-title":"Clozapine-induced hypersalivation: A review of treatment strategies","volume":"52","author":"Sockalingam","year":"2007","journal-title":"Can. J. Psychiatry"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"411","DOI":"10.1358\/dot.2005.41.6.893628","article-title":"Drug-induced sialorrhea","volume":"41","author":"Freudenreich","year":"2005","journal-title":"Drugs Today"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"867","DOI":"10.1002\/med.20158","article-title":"Medicinal chemistry and therapeutic potential of muscarinic M3 antagonists","volume":"29","author":"Peretto","year":"2009","journal-title":"Med. Res. Rev."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"700","DOI":"10.1016\/j.encep.2022.03.013","article-title":"Treatment options for drug-induced sialorrhea: Prescribing guidelines","volume":"48","author":"Cuvelier","year":"2022","journal-title":"L\u2019Enc\u00e9phale"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1097\/YIC.0000000000000251","article-title":"Hyoscine for clozapine-induced hypersalivation: A double-blind, randomized, placebo-controlled cross-over trial","volume":"34","author":"Segev","year":"2019","journal-title":"Int. Clin. Psychopharmacol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1097\/JCP.0000000000001968","article-title":"Comparison of Effectiveness and Tolerability of Clonidine and Trihexyphenidyl in Clozapine-Induced Hypersalivation","volume":"45","author":"Pansawat","year":"2025","journal-title":"J. Clin. Psychopharmacol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1033","DOI":"10.1080\/000486700285","article-title":"Use of atropine eye drops for clozapine induced hypersalivation","volume":"34","author":"Comley","year":"2000","journal-title":"Aust. N. Z. J. Psychiatry"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1016\/j.schres.2016.10.039","article-title":"Sublingual atropine in the treatment of clozapine-induced sialorrhea","volume":"182","author":"Santana","year":"2017","journal-title":"Schizophr. Res."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2905","DOI":"10.1007\/s00213-020-05627-4","article-title":"The effect of sublingual atropine sulfate on clozapine-induced hypersalivation: A multicentre, randomised placebo-controlled trial","volume":"237","author":"Mubaslat","year":"2020","journal-title":"Psychopharmacology"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1007\/s00213-007-0844-6","article-title":"The muscarinic receptor antagonist tropicamide suppresses tremulous jaw movements in a rodent model of parkinsonian tremor: Possible role of M4 receptors","volume":"194","author":"Betz","year":"2007","journal-title":"Psychopharmacology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.jns.2011.05.021","article-title":"A double-blind, placebo-controlled, randomized, crossover pilot study of the safety and efficacy of multiple doses of intra-oral tropicamide films for the short-term relief of sialorrhea symptoms in Parkinson\u2019s disease patients","volume":"310","author":"Lloret","year":"2011","journal-title":"J. Neurol. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"318","DOI":"10.1080\/24750573.2017.1347601","article-title":"Tropicamide ophthalmic solution reduces clozapine-induced sialorrhea: A case report","volume":"27","author":"Kilic","year":"2017","journal-title":"Psychiatry Clin. Psychopharmacol."},{"key":"ref_17","first-page":"138","article-title":"A systematic chart review of pharmacological interventions in patients with clozapine-induced hypersalivation","volume":"268","author":"Mutlu","year":"2023","journal-title":"Schizophr. Res."},{"key":"ref_18","unstructured":"Oxford Health NHS Trust (2023). Clozapine-Induced Hypersalivation Guidelines, Oxford Health NHS Trust. Available online: https:\/\/oxfordhealthformulary.nhs.uk."}],"container-title":["Pharmacy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2226-4787\/14\/4\/101\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,6]],"date-time":"2026-07-06T10:05:11Z","timestamp":1783332311000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2226-4787\/14\/4\/101"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,4]]},"references-count":18,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["pharmacy14040101"],"URL":"https:\/\/doi.org\/10.3390\/pharmacy14040101","relation":{},"ISSN":["2226-4787"],"issn-type":[{"value":"2226-4787","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,4]]}}}