Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344232 (blurred vision)
 2,072 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ethambutol, a synthetic bacteriostatic agent, is a first line agent against Mycobacterium tuberculosis. Although optic neuritis is the most serious adverse effect of ethambutol, most cases in the literature are reversible. Renal failure prolongs the half-life of ethambutol and increases the risk of ethambutol-induced optic neuritis. We present two patients with end stage renal disease (ESRD), who were on maintenance dialysis and suffering ethambutol-induced optic neuritis. The first woman had been suffering ESRD on hemodialysis for 2 years. After tuberculosis was diagnosed, she was prescribed three-combined anti-tuberculosis medications, including ethambutol 800 mg/day. Bilateral blurred vision suddenly occurred 4 months after the start of treatment, and she became totally blind despite discontinuing ethambutol. The second woman had been on hemodialysis for 5 months. Tuberculosis was diagnosed by lung biopsy. After 3 weeks of three-combined anti-tuberculosis medications including ethambutol (1,200 mg/day), reduced visual acuity and color vision defects occurred. One year after the discontinuation of ethambutol, visual acuity remained little improved. Physicians should be aware of ethambutol-induced optic neuritis and ethambutol should be used cautiously in patients with renal failure.
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PMID:Ethambutol-induced optic neuritis in patients with end stage renal disease on hemodialysis: two case reports and literature review. 1528 5

Given the increasing prevalence of tuberculosis, antitubercular drugs frequently used are also associated with ocular toxicity. Ethambutol is the most commonly implicated drug. It is generally well tolerated, but known to cause optic neuritis, more specifically retro bulbar neuritis causing blurred vision, decreased visual acuity, central scotomas, and loss of red-green color vision. The exact mechanism of toxicity is not understood. Though optic neuritis due to ethmabutol is generally considered to be reversible upon prompt discontinuation of the drug, there are reports of reversible toxicity, particularly in the elderly population. Isoniazid can rarely cause retro bulbar neuritis. Dose relationship is usually not seen. Streptomycin is known to cause pseudo tumorcerebri. Thiacetazone can produce severe cutaneous reactions including Steven Johnson Syndrome affecting the skin and mucosa including conjunctiva. Educating the patients for early detection of the ocular manifestations and regular follow-ups are very essential.
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PMID:Ocular side effects of antitubercular drugs - a focus on prevention, early detection and management. 1644 53