Reversible vestibular dysfunction secondary to sotalol use

Excerpt

Cellular responses to stimuli in multiple areas of the human body are dependent on maintenance of normal transmembrane electrical gradients, largely mediated by channels that control intra- and extra-cellular sodium, potassium, and calcium concentrations. Thus, dysfunction of the channels responsible for electrolyte influx and efflux may cause an array of symptoms in otherwise disparate organ systems. For example, patients with cardiac channelopathies such as long QT syndrome have been reported to develop dysfunction of the auditory/vestibular apparatus (Jervell and Lange-Nielsen Syndrome) [1] as well as gastrointestinal symptoms [2]. Thus, it is possible that antiarrhythmics, whose therapeutic effects are realized by direct effects on the function of sodium and potassium channels, may have secondary effects on normal function in other organs. In particular, the potassium channel plays a prominent role in maintaining normal auditory and vestibular function [3]. While sotalol is known to cause lightheadedness in as many as 12%, dizziness in as many as 20% of patients [4], and has been rarely (<1/10,000) associated with vertigo as well [5, 6], pathologic effects on vestibular function have not been reported. We report a case of reversible vestibular dysfunction secondary to sotalol use that, to our knowledge, has not previously been recognized. …