Lithium and hematopoiesis: understanding the systemic impact of long-term use

• DOI: https://doi.org/10.22533/at.ed.159491241410944

• Palavras-chave: Lithium; Hematological effects; Leukocytosis; Erythropoiesis; Thrombocytopenia.

• Keywords: Lithium; Hematological effects; Leukocytosis; Erythropoiesis; Thrombocytopenia.

• Abstract: INTRODUCTION Lithium is recognized as a critical therapeutic agent in the management of mood disorders, particularly bipolar disorder, due to its significant mood-stabilizing properties. Its pharmacodynamic actions, including modulation of neurotransmitter activity and inhibition of pathways like glycogen synthase kinase-3, are central to its efficacy. However, lithium’s narrow therapeutic window necessitates precise monitoring to avoid systemic toxicity, especially in patients undergoing long-term treatment. Beyond its psychiatric benefits, lithium exerts considerable hematological effects, influencing granulopoiesis, bone marrow function, and the production of white and red blood cells. The introduction emphasizes the need to closely monitor hematological parameters during lithium therapy, particularly in relation to leukocytosis, neutrophilia, platelet dysfunction, and anemia. OBJETIVE To explore and analyze the hematological effects of long-term lithium therapy, particularly its impact on leukocytosis, neutrophilia, platelet function, and red blood cell production, while assessing clinical implications for patients. METHODS This is a narrative review which included studies in the MEDLINE – PubMed (National Library of Medicine, National Institutes of Health), COCHRANE, EMBASE and Google Scholar databases, using as descriptors: “Lithium-induced hematological changes” OR “Mood stabilizers and blood cell alterations” OR “Neutrophilia and leukocytosis in lithium therapy” OR “Platelet dysfunction and lithium therapy” OR “Bone marrow suppression and lithium use” in the last  years. RESULTS AND DISCUSSION Lithium therapy is associated with several hematological changes, the most notable being lithium-induced leukocytosis, which is dose-dependent and occurs primarily through increased neutrophil production. This increase in white blood cell count, while often benign, requires close monitoring in patients with preexisting hematological conditions. In addition to leukocytosis, lithium affects red blood cell production, leading to suppressed erythropoiesis and mild anemia in some patients. The results also indicate that lithium’s impact on platelet function, although debated, may reduce platelet aggregation in certain individuals, heightening the risk of bleeding. Long-term lithium use raises concerns about its effect on hematopoietic stem cell proliferation and the potential dysregulation of bone marrow activity, which could pose long-term risks. Particular attention is given to populations like the elderly and those with renal impairment, who are more susceptible to lithium's hematological side effects. CONCLUSION Lithium’s profound therapeutic role in psychiatric care is tempered by its diverse hematological effects, which require consistent and individualized monitoring. Its ability to induce leukocytosis and other blood cell alterations underscores the importance of regular blood tests to mitigate the risks associated with long-term therapy. Anemia and platelet dysfunction, though less common, present additional challenges that need to be managed through careful dose regulation and monitoring, particularly in patients with preexisting conditions. There are potential long-term concerns, such as bone marrow dysregulation, that warrant further research to fully understand lithium’s impact over extended periods of use. The balance between lithium's therapeutic benefits and its hematological risks is crucial, emphasizing the need for a personalized approach to treatment that adapts to each patient’s unique risk factors and clinical profile.