Clozapine-induced blood dyscrasias in Saudi Arab patients
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Background Clozapine has shown superior efficacy over other antipsychotics. However, its use is complicated by the development of life-threatening hematologic adverse effects. Objectives This paper reports the incidence of clozapine-induced hematologic toxicity in Saudi Arab patients. Setting King Khalid University Hospital, Riyadh, Saudi Arabia. Methods Medical data of Saudi Arab hospitalized patients receiving clozapine was retrospectively reviewed during the period between August 2009 and August 2012. White blood cell (WBC) counts and differentials were recorded in a specific form to watch for any hematologic toxicity. The hematologic toxicities included in this report are: eosinophilia, thrombocytopenia, lymphocytopenia, and agranulocytosis/neutropenia/leukopenia combined. Main outcome measure Complete WBC count. Results During the study period 147 charts were reviewed. The mean age of patients was 38 ± 11.42 years and 52 % were males. During the study period 61 patients (42 %) developed 82 blood dyscrasias. Sixteen patients (10.9 %) developed agranulocytosis, neutropenia and leukopenia combined, while nineteen patients (12.9 %) developed lymphocytopenia, and seven patients (4.8 %) developed thrombocytopenia. Eosinophilia developed in 40 patients (27.2 %). During the first 18 weeks of therapy with clozapine, 21 (26 %) hematologic side effects were developed. Conclusion The data collected in this study does appear to indicate there may be an increased incidence of blood dyscrasias in Saudi Arabs which warrants further, more detailed, study. It would be of concern to psychiatric clinicians if the case of a genetic predisposition to clozapine-induced blood dyscrasias were proven in the future.
KeywordsAgranulocytosis Clozapine Drug reactions Saudi Arabia
The authors are grateful to pharmacist Reem Alharbi for her help in accessing patients’ files.
This research project was supported by a Grant from the “Research Center of the Center for Female Scientific and Medical Colleges”, Deanship of Scientific Research, King Saud University.
Conflicts of interest
The authors have no conflicts of interest to declare.
- 8.Baldessarini RJ, Tarazi FI. Pharmacotherapy of psychosis and mania. In: Brunton L, Lazo J, Parker K, editors. Goodman & Gilman’s the pharmacological basis of therapeutics. 11th ed. New York: McGraw-Hill; 2006.Google Scholar
- 10.BNF 62. British National Formulary. London: BMJ publishing and RPS publishing; 2011.Google Scholar
- 14.Lahdelma L, Ahokas A, Andersson LC, Suvisaari J, Hovatta I, Huttunen MO, et al. Mitchell B. Balter Award. Human leukocyte antigen-A1 predicts a good therapeutic response to clozapine with a low risk of agranulocytosis in patients with schizophrenia. J Clin Psychopharmacol. 2001;21(1):4–7.Google Scholar
- 16.Freudenreich O, McEvoy J. 2012. Guidelines for prescribing clozapine in schizophrenia. [ONLINE] http://www.uptodate.com/contents/guifelines-for-prescribing-clozapine-in-schizophrenia?detectedLanguage=en&source=search_result&search=guidelines+for+prescribing+clozapine&selectedTitle=1~150&provider=noProvider. Accessed 5 March 2014.
- 17.Landaw SA, George JN. 2013. Approach to the adult patient with thrombocytopenia. [ONLINE] http://www.uptodate.com/contents/approach-to-the-adult-patient-with-thrombocytopenia. Accessed 5 March 2014.
- 18.Coates T. 2013. Approach to the patient with lymphocytosis or lymphocytopenia. [ONLINE] http://www.uptodate.com/contents/approach-to-the-patient-with-lymphocytosis-or-lymphocytopenia. Accessed 5 March 2014.
- 19.Weller P. 2013. Approach to the patient with eosinophilia. [ONLINE] http://www.uptodate.com/contents/approach-to-the-patient-with-eosinophilia?detectedLanguage=en&source=search_result&search=approach+to+the+patients+with+eosinophilia&selectedTitle=1~150&provider=noProvider. Accessed 5 March 2014.
- 31.Delilers GL. Blood dyscrasias in clozapine-treated patients in Italy. Haematologica. 2000;85(3):233–7.Google Scholar
- 37.Clozapine. In: DRUGDEX system [CD-ROM]. Volume 159. Truven Health Analytics; 2014 (expires March 2014).Google Scholar
- 39.Honigfeld G. Effects of the clozapine national registry system on incidence of deaths related to agranulocytosis. Psychiatric Serv. 1996;47:52–6.Google Scholar