title: Closantel; a veterinary drug with potential severe morbidity in humans.
abstract: BACKGROUND
  Closantel is a halogenated salicylanilide with a potent anti parasitic activity. It is widely used in management of parasitic infestation in animals, but is contraindicated in humans.
  
  
  METHODS
  A 34-year-old man with depression was referred to our center with progressive loss of vision in both eyes 10 days after unintentional 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 IV erythropoietin injections 20,000 units daily for 3 days and 1gr intravenous methylprednisolone acetate for 3 days followed by 1 mg/kg oral prednisolone. On macular optical coherence tomography (OCT), a disruption in outer retina was observed. Electroretinogram and visual evoked potential tests showed visual pathway involvement.
  
  
  CONCLUSIONS
  Destruction of neurosensory retina and visual pathways after accidental Closantel use is related to severe visual loss. This case alerts us about the destructive effect of this drug on humans even in low dosage which necessitates preventive efforts to reduce the chance of this morbid side effect.
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Ali
authors.initials: SA
authors.lastname: Tabatabaei
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran. Soleimani_md@yahoo.com.
authors.forename: Mohammad
authors.identifier: http://orcid.org/0000-0002-6546-3546
authors.initials: M
authors.lastname: Soleimani
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Mansouri
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Mirshahi
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Inanlou
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Abrishami
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ahmad Reza
authors.initials: AR
authors.lastname: Pakrah
authors.affiliation: Eye Research Center, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hamideh
authors.initials: H
authors.lastname: Masarat
mesh_terms: D000328:Adult; D000871:Anthelmintics / Q000506:poisoning*; D006801:Humans; D008297:Male; D012164:Retinal Diseases / Q000139:chemically induced*; D012458:Salicylanilides / Q000506:poisoning*; D019155:Veterinary Drugs / Q000506:poisoning; D014786:Vision Disorders / Q000139:chemically induced*
chemical_list: D000871:Anthelmintics; D012458:Salicylanilides; D019155:Veterinary Drugs; C023342:closantel
keywords: Case; Closantel; Side effect; Visual loss