Phenytoin induced loss of function and delayed dyskinesia

Abstract

Introduction: Older adults are particularly vulnerable to adverse drug effects. The consequences of this are an increase in the number and severity of adverse drug reactions, which worsens their health and quality of life, thereby increasing the use of health care resources and the costs of care.

Objective: To describe the complications induced by the use of phenytoin in an elderly woman.

Case Report: 84-year-old female patient with a personal history of hypertension, hypothyroidism, vascular epilepsy treated with phenytoin for 24 years. She was brought for consultation due to loss of function and uncontrolled movements of the limbs and mouth. The patient was found to be dependent for basic and instrumental activities of daily living and in a confusional state. Elevated blood phenytoin concentrations were noted. After drug withdrawal and multidisciplinary interventions, significant functional improvement was achieved.

Conclusions: It should be kept in mind that a patient exposed to phenytoin for a long time may eventually present adverse effects. We must be attentive to this in order to make an early diagnosis of possible complications derived from the use of this drug.