use of Depakine Chronosphere in Russian clinical practice for first line monotherapy for treatment of adult patients with epilepsy Study objective: to get additional Russian data on Depakine Chronosphere efficacy as a first line monotherapy for treatment of adult patients with epilepsy. Methods: the study was short-term open-label, observational, prospective by its design and was conducted very close to the real clinical practice. Duration of the observation was 2 months. 494 patients older than 18 years (mean 30,2±14,1 years) with different forms of epilepsy were enrolled into the study. Symptomatic focal epilepsy forms were diagnosed in 52% of cases, presumably symptomatic – in 16,8% cases, idiopathic generalized epilepsy – in 29,8%, unspecified – in 1,4%. Patients received Depakine Chronosphere in mean day dosage of 18,58 ± 5,53 mg/kg. Drug efficacy was assessed on the basis of changes in number of seizures. Besides of this, subjective assessment of treatment efficacy was performed by physician and patient. Safety was assessed on the basis of adverse events reports by patients during the observation period. Results: more than 90% of all patients had positive effect on treatment with Depakine Chronosphere (epileptic seizures were stopped and their number reduced). Epileptic seizures were completely stopped in 64,4% of patients. The drug was effective in different forms of epilepsy (in partial and as well as in generalized). Depakine Chronosphere showed good tolerability. Adverse events were observed in 15,7% of patients, but only 0,8% of them led to therapy discontinuation . Physicians and patients assessed treatment efficacy as very good and good in more, than 90% of cases. Good efficacy and tolerability of therapy were confirmed by scale of common clinical assessment – 61,1% of patients had significant improvement and absence of the side effects, 17% of patients had significant improvement and nonsignificant side effects. Conclusion: the study demonstrates efficacy and tolerability of Depakine Chronosphere as monotherapy of epilepsy in adults and it can be considered as a first line therapy.