Levetiracetam in clinical practice: evaluation of efficacy and tolerability in patients with different epilepsy syndromes

Rationale: The aim of this study is to evaluate efficacy and tolerability of levetiracetam (LEV), as adjunctive therapy or as monotherapy, in patients with different epilepsy syndromes. Methods:We evaluated epileptic patients seen in our outpatients facilities in the last 18 months, including in the study all patients with present or past exposure to LEV, independently from duration of LEV therapy. 83 of these patients had already been described in a preliminary report . Tolerability of LEV therapy was evaluated in all patients; efficacy was evaluated only in patients who had received LEV for at least 6 months after titration. Demographic and clinical data were evaluated retrospectively from clinical charts and patients diaries. 202 patients were included in the study; 91 were males and 111 females, with age 7–93 years. 48 patients were affected by Idiopathic Generalized Epilepsy (IGE), 8 by Symptomatic Generalized Epilepsy (SGE), 2 by Idiopathic Focal Epilepsy (IFE), 57 by Cryptogenic Focal Epilepsy (CFE) and 87 by Symptomatic Focal Epilepsy (SFE). 144 patients were drug resistant and received LEV with the aim of improving seizure control (Drug Resistant group, DR). 35 patients already had complete seizure control with AED therapy, but reported severe adverse effects related to treatment: in these subjects LEV was introduced with the aim of reducing or withdrawing previous AED treatment (Adverse Effects group, AE). In the remaining 23 patients, who were not treated with AEDs, LEV was used as first line drug because of its favorable profile (De Novo group, DN). Patients who received LEV for a minimum of 6 months were considered responders when showing a >50% reduction in seizures frequency and non responders when seizures frequency was unchanged, worsened or showed a reduction <50%. Response to LEV therapy was evaluated separately in DR, AE and DN patients. Moreover, in DR patients response to therapy was evaluated separately according to epilepsy type. Results: 30 patients did not complete 6 months of LEV treatment and dropped out, because of adverse effects in 21 cases and of lack of response in 4; the remaining 5 patients dropped out both because of side effects and lack of response. Of the 172 patients who were treated for at least 6 months, 64% were responders, with 40% seizure free (SF). In particular, in the AE group 97% preserved seizure freedom on LEV treatment; 89% of DN patients were responders to LEV, with 58% SF; in the DR group 52% were responders with 23% SF. When DR patients were divided according to epilepsy type, IGE showed 69% responders (42% SF), SGE had 17% responders and no SF, CFE had 53% responders and 25% SF and SFE had 47% responders and 14% SF. IFE group included only 1 patient who was SF. Conclusions: Our study shows LEV as a well tolerated and effective treatment, both in monotherapy and in add-on, with more than half of DR patients being responders to therapy.