Pharmacopsychiatry, Table of Contents Pharmacopsychiatry 2023; 56(05): 204-205DOI: 10.1055/a-2142-8708 Letter to the Editor Valproic Acid Induced Thrombocytopenia in an Elderly Man with Schizoaffective Disorder: A Case Report Yun Tien 1 Psychiatry, Taoyuan Psychiatric Center Ministry of Health and Welfare, Taoyuan, Taiwan › Author Affiliations Recommend Article Abstract Buy Article Key words Key wordsAdverse effects - Schizoaffective disorder - Thrombocytopenia - druginduced Full Text References References 1 Martínez-Lazcano MT, Esplá-González S, Herraiz-Robles P. et al. Use of valproic acid in long stay units of psychiatry. Farm Hosp 2015; 39: 92-101 2 Kishi T, Fujita N, Kawaguchi H. et al. Bone marrow suppression induced by high dose valproic acid. Arch Dis Child 1994; 71: 153-155 3 Rousan TA, Aldoss IT, Cowley BD. et al. Recurrent acute thrombocytopenia in the hospitalized patient: Sepsis, DIC, HIT, or antibiotic-induced thrombocytopenia. Am J Hematol 2010; 85: 71-74 4 Akgun Y, Baykara Y, Langlie J. et al. Valproic acid induced thrombocytopenia and dysmegakaryopoiesis in a pediatric patient. Ann Clin Lab Sci 2022; 52: 843-845 5 Post DS, van der Veer A, Schijns O. et al. Assessment of need for hemostatic evaluation in patients taking valproic acid: A retrospective cross-sectional study. PLoS One 2022; 17: e0264351 6 Allarakhia IN, Garofalo EA, Komarynski MA. et al. Valproic acid and thrombocytopenia in children: A case-controlled retrospective study. Pediatr Neurol 1996; 14: 303-307 7 Nasreddine W, Atweh SF, Beydoun AA. et al. Predicting the occurrence of thrombocytopenia from free valproate levels: A prospective study. Seizure 2022; 94: 33-38 8 McNamara NA, Dang LT, Sturza J. et al. Thrombocytopenia in pediatric patients on concurrent cannabidiol and valproic acid. Epilepsia 2020; 61: e85-e89 9 Kumar R, Vidaurre J, Gedela S. Valproic acid-induced coagulopathy. Pediatr Neurol 2019; 98: 25-30