Introduction: Epilepsy is a chronic neurological disorder characterized by recurrent seizures of cerebral origin which have been known to inflict mankind since ancient times. The seizure nearly always correlates with an abnormal EEG discharge. Epilepsy continues to be one of the commonest disorders seen in neurology clinics all over the world. Hence the antiepileptic drugs are the most abundantly prescribed drugs by the neurologist and phenytoin being the most effective, it is widely prescribed as first line drugs in spite of many newer antiepileptics. Unfortunately phenytoin has a wide spectrum of adverse effects ranging from being reversible effect to severe life threatening conditions. Objective: The objective of the current study is to analyze and evaluate the adverse effects of phenytoin in the Neurology department in a tertiary care teaching hospital in North East India.

Methodology: This study was a prospective observational study on patients in the neurology department. A random once weekly data collection was done for a period of 1 year. Patients of all ages and both sexes were included in the study. Informed consent was obtained verbally from the patient’s legal guardian. Every patient was examined clinically and their side effects were detected. Patient related information and drug related information (like dose, dosage form, route of administration) was recorded on a data collection sheet. The data obtained was analysed and presented with appropriate statistical methods.

Results: Most common adverse effects of phenytoin observed in the study were gum hyperplasia (24%), dermatological changes comprising skin pigmentation, coarsening of facial features and hirsutism, CNS related ataxia, nystagmus and cerebellar involvement (20%).

Keywords: epilepsy, phenytoin, adverse drug effects, prospective study, gum hyperplasia.