Accidental hydroxychloroquine overdose resulting in neurotoxic vestibulopathy

Abstract

Hydroxychloroquine is an oral antimalarial medication commonly used off-label for a variety of rheumatological conditions, including systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome and dermatomyositis. We present a case of a 64-year-old woman who presented with acute onset headache, bilateral tinnitus, and left-sided facial numbness and tingling in the setting of accidentally overdosing on hydroxychloroquine. By the next morning, the patient began to experience worsening in the tingling sensation and it eventually spread to her left arm, thigh and distal extremities. The patient also complained of new onset blurring of her peripheral vision and feeling 'off balance.' Despite a complete neurological and ophthalmological work-up with unremarkable imaging and blood work, the patient has had no improvement in her tinnitus, left-sided paresthesias, visual disturbance or ataxia. This is a unique case of hydroxychloroquine overdose resulting in permanent neurotoxic vestibulopathy.

Keywords: Emergency medicine; Neurological injury; Rheumatology; Sjogren's syndrome.

Figure 1

Image of filled pill box compartments prior to submersion in water.

Figure 2

Image of pill box compartments after falling into water and soaking for an hour.

Figure 3

Image of normal Plaquenil pill on top compared with partially dissolved pill on the bottom.