Evaluation of frequency, characteristics, and risk factors of neurotoxicity in patients on long-term amiodarone by nerve conduction studies

Abstract

Background: Amiodarone is an iodine-rich drug that is a highly effective and widely used as an antiarrhythmic agent for the treatment of symptomatic supraventricular and ventricular tachyarrhythmias. Amiodarone is associated with many adverse effects that involve different organs. Incidence of neurologic problems like peripheral neuropathy has been reported after long-term usage of amiodarone.
Aim of the Study: The aim of the present study is to evaluate the incidence of neurologic problems like peripheral neuropathy in patients on long-term medication with amiodarone.
Materials and Methods: We carried a retrospective medical record analysis of cardiac patients treated with amiodarone at Prathima Institute of Medical Sciences, Karimnagar, Telangana, from January 1, 2015 to December 31, 2017. 27 patients on long-term amiodarone therapy with neurologic problems were compared with 15 controls without neurological disease. Patients on whom nerve conduction studies and electromyography were performed after admission were selected. All possible neurologic adverse effects that might be attributable to amiodarone were recorded and tabulated.
Results: Neurologic problems included tremor, gait ataxia, peripheral neuropathy, and cognitive impairment. The primary risk factor for amiodarone neurotoxic effects was duration of treatment, not age, drug dose, sex, or indication for therapy.
Conclusion: Amiodarone infrequently causes clinically significant neurologic toxic effects. Substantially higher estimates of neurotoxic effects in the early studies may be related to a much higher daily dose during those times.