{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,24]],"date-time":"2026-06-24T22:35:59Z","timestamp":1782340559237,"version":"3.54.5"},"reference-count":16,"publisher":"BMJ","issue":"9","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2021,8,29]]},"published-print":{"date-parts":[[2021,9]]},"abstract":"<jats:p>Clozapine is an atypical antipsychotic used in refractory schizophrenia, also efficient in alleviating dyskinesia in Parkinson\u2019s disease. Despite its potency, this drug is associated with severe metabolic side effects, including increased risk for diabetes. We report the case of a 45-year-old overweight woman with Parkinson\u2019s disease who presented with rapid-onset hyperglycaemia within 2\u2009months after starting clozapine for refractory dyskinaesia. She had a history of gestational diabetes. At presentation, her blood glucose level was 505\u2009mg\/dL and glycated haemoglobin 12.4%, with no catabolic symptoms. Clozapine was suspended and metformin was started, but adequate glycaemic control was achieved only with insulin therapy, along with exenatide and empagliflozin afterwards. We assume that clozapine acted as a trigger for rapid deterioration of glycaemic control through direct pathophysiological mechanisms, rather than an indirect slowly evolving weight gain-related metabolic syndrome pathway. Clinicians should be aware of this complication, enabling timely diagnosis and proper treatment.<\/jats:p>","DOI":"10.1136\/bcr-2021-243938","type":"journal-article","created":{"date-parts":[[2021,9,13]],"date-time":"2021-09-13T11:36:36Z","timestamp":1631532996000},"page":"e243938","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":4,"title":["Rapid-onset clozapine-induced hyperglycaemia: pathways of glycaemic dysregulation"],"prefix":"10.1136","volume":"14","author":[{"given":"Mariana","family":"Barbosa","sequence":"first","affiliation":[{"name":"Endocrinology Department, Braga Hospital, Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vera","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Endocrinology Department, Braga Hospital, Braga, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2021,9,13]]},"reference":[{"key":"2025082700142932000_14.9.e243938.1","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1007\/s40263-016-0311-1","article-title":"Worldwide differences in regulations of clozapine use","volume":"30","author":"Nielsen","year":"2016","journal-title":"CNS Drugs"},{"key":"2025082700142932000_14.9.e243938.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.parkreldis.2004.04.007"},{"key":"2025082700142932000_14.9.e243938.3","doi-asserted-by":"crossref","first-page":"1336","DOI":"10.3390\/cells8111336","article-title":"Second-generation antipsychotics and dysregulation of glucose metabolism: beyond weight gain","volume":"8","author":"Grajales","year":"2019","journal-title":"Cells"},{"key":"2025082700142932000_14.9.e243938.4","doi-asserted-by":"crossref","first-page":"323","DOI":"10.9758\/cpn.2016.14.4.323","article-title":"Clozapine monitoring in clinical practice: beyond the mandatory requirement","volume":"14","author":"Kar","year":"2016","journal-title":"Clin Psychopharmacol Neurosci"},{"key":"2025082700142932000_14.9.e243938.5","doi-asserted-by":"publisher","DOI":"10.1176\/appi.ajp.157.6.975"},{"key":"2025082700142932000_14.9.e243938.6","doi-asserted-by":"crossref","first-page":"3663","DOI":"10.1007\/s00213-016-4411-x","article-title":"Diabetic ketoacidosis in patients exposed to antipsychotics: a systematic literature review and analysis of danish adverse drug event reports","volume":"233","author":"Polcwiartek","year":"2016","journal-title":"Psychopharmacology"},{"key":"2025082700142932000_14.9.e243938.7","doi-asserted-by":"publisher","DOI":"10.1080\/10401230701338169"},{"key":"2025082700142932000_14.9.e243938.8","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1192\/bjpo.bp.117.004481","article-title":"Rapid-onset clozapine-induced loss of glycaemic control: case report","volume":"3","author":"Porras-Segovia","year":"2017","journal-title":"BJPsych Open"},{"key":"2025082700142932000_14.9.e243938.9","doi-asserted-by":"crossref","first-page":"e100045","DOI":"10.1136\/gpsych-2018-100045","article-title":"Acute onset clozapine-induced hyperglycaemia: a case report","volume":"32","author":"Kumar","year":"2019","journal-title":"Gen Psychiatr"},{"key":"2025082700142932000_14.9.e243938.10","unstructured":"Melmed S , Polonsky KS , Larsen PR . 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