Background: Valproic acid (VPA) is a commonly used drug in children in the management of childhood epilepsies. This cross sectional study was conducted to evaluate the prevalence of various haemostatic abnormalities in children on valproate therapy, as there are no previous studies from India.

Methods: Sixty four consecutive children, aged 3-15 years were enrolled after ethics approval between April 2012 and December 2012. Blood sample was collected after obtaining a detailed history and clinical examination for the analysis of haemostatic parameters, liver function test and serum valproate trough level. Platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), clot solubility test (CST), d Dimer, PF3 release with ADP at 0 and 20 minutes were performed. In children with prolonged PF3 release at 20 minutes, platelet aggregation test (PAT) was performed.

Results: Prevalence of thrombocytopenia, platelet dysfunction and elevated d dimer in children on VPA monotherapy were 20.6%, 69.3% and 85.7% respectively. There was a significant negative correlation between VPA level and platelet count. Five children with prolonged PF3 release at 20 minutes were observed to have an unclassified platelet function disorder on PAT. PT was prolonged in only one patient; APTT, TT and CST were normal in all the children.

Conclusion: Qualitative and quantitative platelet dysfunction were prevalent in children on VPA monotherapy but none were symptomatic. It is essential to screen the children on VPA therapy for haemostatic abnormalities during stress, major trauma, infections, surgery, bleeding symptoms and high VPA level.