Closantel Case Study

Abstract Background Closantel is a halogenated salicylanilides with a potent anti parasiticanti-parasitic activity, . although Although Closantel it is widely used in the management of parasitic infestation in animals, but it is contraindicated in humans. Case Report A 34-year-old depressed mood man with a depressed mood was referred with bilateral progressive loss of vision in both eyes 10 days following after the inadvertent ingestion of three 500 mg tablets of Closantel. On fundus examination, left optic disc margin was blurred. His bilateral visual acuity was no light perception (NLP) despite prescribed His bilateral light perception, visual acuity showed no response to I.V. erythropoietin 20000 units daily for three days and 1gr intravenous
On macular optical coherence tomography (OCT), a disruption in the photoreceptor layer in outer retina was seenobserved. Electroretinogram and visual evoked potential tests, showed visual pathway involvement. Conclusion Destruction of neurosensory retina and visual pathways is related to severe visual loss. This case alerts us about the destructive effect of this drug on humans, even in low dosage, that necessitates preventive efforts for this morbid side effect. Introduction Closantel is a halogenated salicylanilides with a potent anti-parasitic activity, which probably acts mainly via energy metabolism pathway by uncoupling oxidative phosphorylation in liver flukes. It is widely used in the management of parasitic infestations in animals, but is contraindicated in humans and in high dose in milk producing animals because of its secretion in milk. In this report, we present a 34-year-old man who was referred to a tertiary referral ophthalmology hospital, with a chief complain of bilateral progressive loss of vision in both eyes after taking Closantel. What is different in this case The novelty of this presentation, is severe visual loss after taking this veterinary
(3) The term “status spongiosis” in animals refers to spongy vacuolation of white matter as seen by light microscopy. Electron microscopy demonstrates intracellular, extracellular and intramyelinic accumulation of fluid.(2) The exact pathogenesis of myelin spongiosis is not well understood. Myelin splitting as a result of some exogenous or endogenous substance intoxication such as nitrobenzene is a well-described condition in sheep and goats.(2, 9, 10) Nitrobenzene which acts by uncoupling of mitochondrial phosphorylation results in similar changes in oligodendrocytes.(11) Closantel is a salicylanilide drug which mainly interrupts oxidative phosphorylation in helminths.(1) Due to the similarity in the mechanism of action, myelin spongiosis might be a possible explanation for Closantel toxicity. Severe reduction in visual acuity was the main presenting picture of our patient. We didn’t observe any accompanied central nervous system symptoms. Brain imaging was normal. Mild