{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,4]],"date-time":"2025-10-04T01:24:48Z","timestamp":1759541088245,"version":"3.44.0"},"reference-count":10,"publisher":"BMJ","issue":"9","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Case Rep"],"accepted":{"date-parts":[[2025,8,30]]},"published-print":{"date-parts":[[2025,9]]},"abstract":"<jats:p>Tocilizumab, an interleukin-6 (IL-6) receptor antagonist, is widely used for inflammatory diseases such as rheumatoid arthritis and adult-onset Still\u2019s disease (AOSD). While its known side effects include hypersensitivity, neutropenia and liver dysfunction, hypokalaemia is a rare adverse effect. We report a male patient in his early 30s with AOSD who developed severe hypokalaemia (2.0\u2009mmol\/L) and acute flaccid paralysis after his third intravenous tocilizumab infusion. He had no prior neurological or electrolyte disturbances. Electrocardiography showed U waves and mild QT prolongation, while brain and spinal MRI ruled out other causes. Potassium replacement led to full recovery within 24 hours, and his treatment was switched to adalimumab. This case suggests that IL-6 inhibition may disrupt potassium homeostasis, leading to hypokalaemia. Hypokalaemia should be kept in mind in cases of sudden onset of paralysis under tocilizumab treatment.<\/jats:p>","DOI":"10.1136\/bcr-2025-266110","type":"journal-article","created":{"date-parts":[[2025,9,18]],"date-time":"2025-09-18T05:05:18Z","timestamp":1758171918000},"page":"e266110","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":1,"title":["Tocilizumab and electrolyte imbalance: severe hypokalaemia leading to paralysis"],"prefix":"10.1136","volume":"18","author":[{"given":"\u0130rada","family":"\u0130bramkhalilova","sequence":"first","affiliation":[{"name":"Department of Rheumatology, SANKO University, Gaziantep, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fatih","family":"Demir","sequence":"additional","affiliation":[{"name":"Department of Neurology, SANKO University, Gaziantep, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5105-0292","authenticated-orcid":false,"given":"Zeynel Abidin","family":"Sayiner","sequence":"additional","affiliation":[{"name":"Department of Endocrinology and Metabolism, SANKO University, Gaziantep, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bunyamin","family":"Kisacik","sequence":"additional","affiliation":[{"name":"Department of Rheumatology, SANKO University, Gaziantep, Turkey"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2025,9,17]]},"reference":[{"key":"2025091722050944000_18.9.e266110.1","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.ejim.2018.06.008","article-title":"Tocilizumab as an add-on therapy to glucocorticoids during the first 3\u202fmonths of treatment of Giant cell arteritis: A prospective study","volume":"57","author":"Samson","year":"2018","journal-title":"Eur J Intern Med"},{"key":"2025091722050944000_18.9.e266110.2","doi-asserted-by":"crossref","DOI":"10.1186\/s12882-023-03131-3","article-title":"Steroid-induced hypokalemic periodic paralysis: a case report and literature review","volume":"24","author":"Tai","year":"2023","journal-title":"BMC Nephrol"},{"key":"2025091722050944000_18.9.e266110.3","first-page":"59","article-title":"Potassium Disorders: Hypokalemia and Hyperkalemia","volume":"107","author":"Kim","year":"2023","journal-title":"Am Fam Physician"},{"key":"2025091722050944000_18.9.e266110.4","first-page":"424","article-title":"Preliminary criteria for classification of adult Still\u2019s disease","volume":"19","author":"Yamaguchi","year":"1992","journal-title":"J Rheumatol"},{"key":"2025091722050944000_18.9.e266110.5","doi-asserted-by":"publisher","DOI":"10.1111\/j.1472-8206.2010.00859.x"},{"key":"2025091722050944000_18.9.e266110.6","doi-asserted-by":"publisher","DOI":"10.1038\/nrneph.2010.175"},{"key":"2025091722050944000_18.9.e266110.7","doi-asserted-by":"publisher","DOI":"10.1080\/21645515.2017.1316909"},{"key":"2025091722050944000_18.9.e266110.8","doi-asserted-by":"crossref","unstructured":"Alubaidi G , Humadi Y , Hamoodi D , et al . Serum Interleukin-6 is associated with hypocalcemia, hypoferritinemia and hyperkalemia in end-stage renal disease patients. Ital J Med 2022;16. doi:10.4081\/itjm.2022.1550","DOI":"10.4081\/itjm.2022.1550"},{"key":"2025091722050944000_18.9.e266110.9","doi-asserted-by":"crossref","DOI":"10.1002\/rmv.2262","article-title":"Epidemiology, prognosis and management of potassium disorders in Covid-19","volume":"32","author":"Noori","year":"2022","journal-title":"Rev Med Virol"},{"key":"2025091722050944000_18.9.e266110.10","doi-asserted-by":"publisher","DOI":"10.1016\/j.ejim.2007.06.037"}],"container-title":["BMJ Case Reports"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bcr-2025-266110","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,18]],"date-time":"2025-09-18T05:05:20Z","timestamp":1758171920000},"score":1,"resource":{"primary":{"URL":"https:\/\/casereports.bmj.com\/lookup\/doi\/10.1136\/bcr-2025-266110"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9]]},"references-count":10,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9,17]]},"published-print":{"date-parts":[[2025,9]]}},"alternative-id":["10.1136\/bcr-2025-266110"],"URL":"https:\/\/doi.org\/10.1136\/bcr-2025-266110","relation":{},"ISSN":["1757-790X"],"issn-type":[{"type":"electronic","value":"1757-790X"}],"subject":[],"published":{"date-parts":[[2025,9]]}}}