Abstracts

Rationale: Haematological side effects are among the most commonly reported adverse reactions in patients treated with several of the old antiepileptic drugs (AEDs), i.e.carbamazepine (CBZ), valproate (VPA) and phenytoin. These effects develop insidiously over time, but may have serious consequences for the patient and can even be life-threatening. Little is known about haematological side effects of the newer AEDs. There have been only a few sporadic reports of isolated neutropenia or thrombocytopenia associated with the use of lamotrigine (LTG) and levetiracetam (LEV). The aim of our study was to investigate hematological changes in patients treated with the newer AEDs LEV and LTG, compared to the older AEDs VPA and CBZ. Methods: : In a cross-sectional study of 251 patients with AED monotherapy for at least six months, we assessed the effect of CBZ (n=90; females/males: 29/61), VPA (n=29; females/males: 14/15), LEV (n=52; females/males: 21/31) or LTG (n=80; females/males: 43/37) on hemoglobin (Hb), white blood cells (WBC) and platelets. Additionally, the results were compared to 79 healthy controls (females/males: 43/36). The subjects were between the age of 18 and 45 years old and recruited from hospitals in the South Eastern part of Norway and the Department of Neurology of the University Hospital Innsbruck, Austria. Results: The study showed significantly lower platelets count in both men and women under LEV monotherapy. Among patients on LEV monotherapy, platelets were 14 % lower (40,68 x 1012 / L lower) when compared to the control group (95% CI ranging from 20,2-61,2 x 1012 / L). There was no difference in sex or age. Other changes were small, with a statistically significant higher WBC in women with either CBZ, VPA, LEV or LTG, higher Hb in women with LEV and lower Hb for men treated with CBZ. Conclusions: Both men and women treated with LEV monotherapy have lower platelets count than healthy controls, with no difference in Hb or WBC. The effect of LEV on platelets count has not been described in larger, clinical studies to date. Recent case reports, however, have raised concern of a possible risk for bleeding during LEV treatment due to altered thrombocyte function in selected patients (1,2). The effect of LEV on platelet function should therefore be explored further. 1. Herrman H, Taub ll, Gjerstad L. Levetiracetam-induced thrombocytopathia. North American Regional Epilepsy Meeting, San Diego, USA, Dec 2006. 2. Hacquard M, Richard S, Lacour JC, Lecompt T, Vespignani H. Levetiracetam induced platelet dysfunction. Epilepsy Research 2009; 86: 94-6.