title: Spectrum of digoxin-induced ocular toxicity: a case report and literature review.
abstract: BACKGROUND
  Digoxin intoxication results in predominantly digestive, cardiac and neurological symptoms. This case is outstanding in that the intoxication occurred in a nonagenarian and induced severe, extensively documented visual symptoms as well as dysphagia and proprioceptive illusions. Moreover, it went undiagnosed for a whole month despite close medical follow-up, illustrating the difficulty in recognizing drug-induced effects in a polymorbid patient.
  
  
  METHODS
  Digoxin 0.25 mg qd for atrial fibrillation was prescribed to a 91-year-old woman with an estimated creatinine clearance of 18 ml/min. Over the following 2-3 weeks she developed nausea, vomiting and dysphagia, snowy and blurry vision, photopsia, dyschromatopsia, aggravated pre-existing formed visual hallucinations and proprioceptive illusions. She saw her family doctor twice and visited the eye clinic once until, 1 month after starting digoxin, she was admitted to the emergency room. Intoxication was confirmed by a serum digoxin level of 5.7 ng/ml (reference range 0.8-2 ng/ml). After stopping digoxin, general symptoms resolved in a few days, but visual complaints persisted. Examination by the ophthalmologist revealed decreased visual acuity in both eyes, 4/10 in the right eye (OD) and 5/10 in the left eye (OS), decreased color vision as demonstrated by a score of 1/13 in both eyes (OU) on Ishihara pseudoisochromatic plates, OS cataract, and dry age-related macular degeneration (ARMD). Computerized static perimetry showed non-specific diffuse alterations suggestive of either bilateral retinopathy or optic neuropathy. Full-field electroretinography (ERG) disclosed moderate diffuse rod and cone dysfunction and multifocal ERG revealed central loss of function OU. Visual symptoms progressively improved over the next 2 months, but multifocal ERG did not. The patient was finally discharged home after a 5 week hospital stay.
  
  
  CONCLUSIONS
  This case is a reminder of a complication of digoxin treatment to be considered by any treating physician. If digoxin is prescribed in a vulnerable patient, close monitoring is mandatory. In general, when facing a new health problem in a polymorbid patient, it is crucial to elicit a complete history, with all recent drug changes and detailed complaints, and to include a drug adverse reaction in the differential diagnosis.
authors: Division of Clinical Pharmacology, University Hospital of Lausanne, Bugnon 17-01, 1011, Lausanne, Switzerland. delphine.renard@chuv.ch.
authors: Delphine
authors: D
authors: Renard
authors: Service de gériatrie et réadaptation gériatrique, CHUV, CUTR Sylvana, Ch. de Sylvana 10, 1066, Epalinges, Switzerland. eve.rubli@chuv.ch.
authors: Eve
authors: E
authors: Rubli
authors: Département d'ophtalmologie, Université de Lausanne, Fondation Asile des Aveugles, Hôpital ophtalmique Jules-Gonin, av. de France 15, 1000, Lausanne 7, Switzerland. nathalie.voide@gmail.com.
authors: Nathalie
authors: N
authors: Voide
authors: Département d'ophtalmologie, Université de Lausanne, Fondation Asile des Aveugles, Hôpital ophtalmique Jules-Gonin, av. de France 15, 1000, Lausanne 7, Switzerland. francois.borruat@fa2.ch.
authors: François-Xavier
authors: FX
authors: Borruat
authors: Division of Clinical Pharmacology, University Hospital of Lausanne, Bugnon 17-01, 1011, Lausanne, Switzerland. laura.rothuizen@chuv.ch.
authors: Laura E
authors: LE
authors: Rothuizen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D004077:Digoxin / Q000009:adverse effects*; D004596:Electroretinography; D005123:Eye / Q000187:drug effects* / Q000503:physiopathology; D005260:Female; D006801:Humans; D014792:Visual Acuity
chemical_list: D000889:Anti-Arrhythmia Agents; D004077:Digoxin