Correspondence (letter to the editor): Amiodarone-Associated Vestibulopathy

The successful review by C. Sommer and colleagues (1) should be supplemented with information about a recently discovered new facet of toxic polyneuropathy as a side effect of amiodarone (2). As has emerged in the past year, this common antiarrhythmic drug is responsible not only for sensorimotor symptoms in polyneuropathy, but also for sensory—and more specifically, vestibular—neuropathy, as it causes a bilateral loss of balance (bilateral vestibulopathy) (3). The clinical appearance of bilateral vestibulopathy is vertigo, gait instability, oscillopsia, and risk of falls. Thus, in one dizziness center, 43% of patients taking amiodarone had bilateral vestibulopathy (2). Further, a recent retrospective multi-center study showed that 12% of patients with “idiopathic” bilateral vestibulopathy were taking amiodarone (3). This phenomenon has not been previously reported in the literature. The probable explanation for this is that the affected patients usually also have sensory polyneuropathy (or other central nervous symptoms), which may also cause gait instability, resulting in the symptoms being attributed to these diseases and the balance function not being examined (4). Today, a wide range of functional tests for the balance system is available, which can quickly and reliably document vestibulopathy as the cause of dizziness and gait instability. Therefore, patients taking amiodarone who present with dizziness and/or gait instability should undergo vestibular function testing. Only then can this side effect be recognized early and be included in the benefit–risk assessment of amiodarone therapy.