Haematological side effects of antiepileptic drug treatment in patients with epilepsy

Objectives - Little is known about the haematological side effects of the newer antiepileptic drugs (AEDs), but recent case reports have raised concerns regarding the possibility of altered thrombocyte counts or function in some patients during levetiracetam (LEV) treatment. The aim of our study was to investigate haematological changes in patients treated with the newer AEDs, LEV and lamotrigine (LTG), compared with the older AEDs, valproate (VPA) and carbamazepine (CBZ). Methods - This cross-sectional study included 251 patients with epilepsy of both genders, aged 18-45 years, using AED monotherapy: 52 patients on LEV (31 men, 21 women), 80 on LTG (37 men, 43 women), 90 on CBZ (61 men, 29 women), 29 on VPA (15 men, 14 women), and 79 healthy controls (36 men, 43 women). Haemoglobin (Hb), white blood cells (WBC) and platelet (thrombocyte) counts were estimated. The subjects were recruited from hospitals in south-eastern Norway and Innsbruck, Austria. Results - Significantly lower platelet counts were recorded in both men and women on LEV monotherapy. In the LEV group, platelets were 14% lower (40.68 x 10(9)/l lower) than in the control group. There was no difference according to sex or age of the patients. Only minor changes in haematological parameters were observed for the other drugs investigated. Conclusions - Both men and women treated with LEV monotherapy have lower blood platelet counts than healthy controls, with no difference in Hb or WBC. Haematological changes observed with the other AEDs were minor.