International Medical Case Reports Journal (Jan 2022)
Two Patients with Schizophrenia Treated with Clozapine Developed Neutropenia After Receiving a COVID-19 Vaccine
Abstract
Tetsu Tomita, Yui Sakamoto, Manabu Saito, Kojiro Hashimoto, Yasuki Ono, Kazuhiko Nakamura Department of Neuropsychiatry, Graduate School of Medicine, Hirosaki University, Hirosaki, JapanCorrespondence: Tetsu Tomita, Tel +81-172 39 5066, Fax +81-172 39 5067, Email [email protected]: We observed two cases of patients with schizophrenia who were treated with clozapine (250mg/day and 275mg/day, respectively) and showed neutropenia after receiving a COVID-19 vaccine (BNT162b2).Case Presentation: Case 1 is a twenty-two year old woman with a diagnosis of schizophrenia. She enrolled in Clozaril® Patient Monitoring Service in 2017 and had been taking clozapine for 4 years. She received two doses of a COVID-19 vaccine and developed neutropenia (1850/mm3 (37.9% of white blood cell 4880/mm3)) 6 days after the second vaccination, but her neutropenia self-resolved naturally. Case 2 is a twenty year old woman with a diagnosis of schizophrenia. She enrolled in Clozaril® Patient Monitoring Service in 2020 and had been taking clozapine for 10 months. She received two doses of a COVID-19 vaccine and white blood cell and neutrocyte counts were below (3730/mm3 and 1440/mm3 (38.6%), respectively) the lower limits 3 days after the second vaccination. She had to discontinue clozapine according to the withdrawal definition (her neutrocyte count was < 1500/mm3), and her neutropenia self-resolved naturally.Conclusion: Physicians need to have a strict follow-up protocol in place for patients after vaccination for COVID-19.Keywords: clozapine, COVID-19, vaccine, neutropenia
