Date: {{$ActivityAssignDate}}

Dear Dr. {{ $doctorName }},

Subject: A survey to assess the usage pattern of Oxcarbazepine in the management of epilepsy in India

Epilepsy is characterized by recurrent seizures caused by abnormal neuronal discharges in the brain. ^{i, ii, iii.} Epilepsy is the third leading contributor to the global burden of disease for neurological disorders the global burden of disease for neurological disorders and affects 65 million people worldwide.^{iv, v} According meta-analysis of international studies, the prevalence of epilepsy is 6.4 cases per 1,000 persons and the annual incidence is 67.8 cases per 100,000 person-years.^vi

t is estimated that there are more than 10 million persons with epilepsy (PWE) in India^vii. Its prevalence is about 1% in our population. The prevalence is higher in the rural (1.9%) compared to urban population (0.6%).^{viii, ix}

Commonly used medications for partial epilepsy include carbamazepine and lamotrigine valproate, topiramate, oxcarbazepine, or gabapentin.^x Recommendations for the treatment of epilepsy in adult and paediatric patients in Belgium: 2020 update mentions carbamazepine, lamotrigine, levetiracetam and oxcarbazepine are recommended as first choice for focal seizure.^xi

Mechanism of action of oxcarbazepine and 10-monohydroxy metabolite MHD is presumably attributed to the blockade of voltage sensitive sodium channels, thus resulting in stabilisation of hyperexcited neural membranes, inhibition of repetitive neuronal firing and diminution of propagation of synaptic impulses. These actions are considered important in the prevention of seizure spread in the intact brain

A prospective, open-label, multicentre study evaluated the efficacy and tolerability of oxcarbazepine as monotherapy in patients with partial seizures who switched from their current antiepileptic drug (AED) monotherapy because of lack of efficacy or poor tolerability showed overall, 52% of patients experienced a ≥ 50% reduction in seizure frequency, 35% had a ≥ 75% reduction, and 18% were seizure-free. The most frequent (>10%) adverse events were dizziness, nausea, headache, somnolence, and fatigue.^xii

This survey has been undertaken to assess the usage pattern of Oxcarbazepine in the management of epilepsy in India.

As you will be spending some extra time to give your feedback on the questionnaire based on your clinical experience, we offer to pay you by cheque a professional fee of Rs {{$contractAmount}}, on receiving the completed Survey Questionnaire Form from you.

We trust you and we are partners in promoting effective drug therapy. In that spirit we hope you will consent to participate in this survey. If you do, please sign and return the enclosed reply along with your visiting card for accuracy of records.

Yours truly,

Mr. Ravisankar Viswanathan

Cluster Head, CNS

Sun Pharma Laboratories Limited

i : National Institute for Clinical Excellence. Technology appraisal 76: newer drugs for epilepsy in adults. London: National Institute of Clinical Excellence, 2004 Mar

ii : National Institute for Clinical Excellence. Technology appraisal 79: newer drugs for epilepsy in children. London: National Institute of Clinical Excellence, 2004 Apr

iii : Proposal for revised classification of epilepsies and epileptic syndromes: commission on Classification and Terminology of the International League Against Epilepsy. Epilepsia 1989; 30 (4): 389-99

iv : Prevalence Collaborators et al. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990‑2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet 388, 1545–1602 (2016)

v : Ngugi, A. K., Bottomley, C., Kleinschmidt, I., Sander, J. W. & Newton, C. R. Estimation of the burden of active and life-time epilepsy: a meta-analytic approach. Epilepsia 51, 883–890 (2010).

vi : Fiest, K. M. et al. Prevalence and incidence of epilepsy: a systematic review and meta-analysis of international studies. Neurology 88, 296–303 (2017)

vii : Leonardi M, Ustun TB. The global burden of epilepsy. Epilepsia 2002; 43(Suppl 6):21-5.

viii : Pahl K, de Boer HM. Epilepsy and rights. Atlas: Epilepsy Care in the World. Geneva: WHO; 2005. p. 72-3.

ix : Lyseng-Williamson KA. Levetiracetam: a review of its use in epilepsy. Drugs. 2011 Mar 5;71 (4):489-514.

x : Patel PR, De Jesus O. Partial Epilepsy. 2023 Feb 12. In: StatPearls [Internet]. Treasure Island (FL) : StatPearls Publishing; 2023 Jan–. PMID: 33232046.

xi : Ngugi, A. K., Bottomley, C., Kleinschmidt, I., Sander, J. W. & Newton, C. R. Estimation of the burden of active and life-time epilepsy: a meta-analytic approach. Epilepsia 51, 883–890 (2010).

xii : Martinez W, Ingenito A, Blakeslee M, Barkley GL, McCague K, D'Souza J. Efficacy, safety, and tolerability of oxcarbazepine monotherapy. Epilepsy Behav. 2006 Nov;9(3):448-56.