title: Optic neuritis with concurrent etanercept and isoniazid therapy.
abstract: OBJECTIVE
  To report a case of optic neuritis associated with concurrent etanercept and isoniazid therapy.
  
  
  METHODS
  A 55-year-old man diagnosed as having rheumatoid arthritis had received treatment with nonsteroidal antiinflammatory drugs, sulfasalazine, oral methotrexate, leflunomide, and deflazacort. Four months prior to admission, he had a Disease Activity Score of 6.06; treatment with etanercept was considered. Three months prior to admission, because of evidence of latent tuberculosis, isoniazid 300 mg once daily and pyridoxine 50 mg once daily were prescribed. Treatment with subcutaneous etanercept 25 mg twice weekly was started 5 days after isoniazid was initiated. Two weeks prior to admission, the patient developed blurred vision in his left eye. Ten days later, his vision worsened and he was hospitalized. The visual acuity in both eyes was 0.7, and a campimetric examination was compatible with optic neuritis. Magnetic resonance imaging of the brain revealed lesions suggesting demyelinating lesions. The clinical course was consistent with bilateral optic neuritis. Etanercept was stopped, and isoniazid was replaced with rifampin 600 mg once daily. The patient was treated with intravenous methylprednisolone hemisuccinate 1 g/day for 5 days followed by oral prednisolone, resulting in a minor subjective improvement in left eye visual acuity. He then received oral prednisone for 3 weeks, slowly tapering to discontinuation.
  
  
  CONCLUSIONS
  No physiologic factors could have predisposed this patient to develop optic neuritis. He was not diagnosed with a demyelinating disease or underlying systemic condition. The optic neuritis was unlikely to be an early manifestation of multiple sclerosis based on the clinical course and the negative results of the imaging tests. Furthermore, there was a close temporal correlation between the drug exposure and the onset of symptoms. After discontinuation of etanercept and isoniazid therapy, the patient's general condition improved. Use of the Naranjo probability scale indicated a possible relationship between optic neuritis and combined etanercept-isoniazid therapy.
  
  
  CONCLUSIONS
  Patients initiated on etanercept and isoniazid should be closely monitored for the development of adverse neurologic signs and effects. If optic neuritis is determined, etanercept and isoniazid should be discontinued immediately.
authors.affiliation: Rheumatology Section, Hospital General Universitario de Elche, Alicante, Spain.
authors.forename: Raul
authors.initials: R
authors.lastname: Noguera-Pons
authors.forename: Joaquín
authors.initials: J
authors.lastname: Borrás-Blasco
authors.forename: Isabel
authors.initials: I
authors.lastname: Romero-Crespo
authors.forename: Rosa
authors.initials: R
authors.lastname: Antón-Torres
authors.forename: Andrés
authors.initials: A
authors.lastname: Navarro-Ruiz
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: González-Ferrandez
mesh_terms: D000995:Antitubercular Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000188:drug therapy; D004359:Drug Therapy, Combination; D000068800:Etanercept; D006801:Humans; D007074:Immunoglobulin G / Q000009:adverse effects*; D007155:Immunologic Factors / Q000009:adverse effects*; D007538:Isoniazid / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009902:Optic Neuritis / Q000139:chemically induced*; D018124:Receptors, Tumor Necrosis Factor; D014376:Tuberculosis / Q000150:complications / Q000188:drug therapy; D014786:Vision Disorders / Q000139:chemically induced; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D000995:Antitubercular Agents; D007074:Immunoglobulin G; D007155:Immunologic Factors; D018124:Receptors, Tumor Necrosis Factor; D000068800:Etanercept; D007538:Isoniazid