title: Fluoroquinolone-associated myasthenia gravis exacerbation: evaluation of postmarketing reports from the US FDA adverse event reporting system and a literature review.
abstract: BACKGROUND
  Exacerbations of myasthenia gravis have been reported in antibacterial-treated patients. In animal and in vitro models of experimentally-induced myasthenia gravis, fluoroquinolones exhibit neuromuscular blockade.
  
  
  OBJECTIVE
  The aim of this retrospective study was to evaluate postmarketing adverse event reports submitted to the US FDA and case reports published in the scientific literature for a potential association between fluoroquinolone exposure and acute exacerbations of myasthenia gravis.
  
  
  METHODS
  On 1 March 2011, we searched the FDA Adverse Event Reporting System (AERS) database to retrieve all reports of myasthenia gravis exacerbation as a serious adverse event in patients treated with fluoroquinolones. We also conducted an Internet-based search using EMBASE for additional English-language cases in the scientific literature.
  
  
  RESULTS
  We identified a total of 37 unique cases describing myasthenia gravis exacerbation following fluoroquinolone systemic exposure. We retrieved AERS reports for 27 non-ventilated patients administered the following fluoroquinolones: levofloxacin (n = 9), moxifloxacin (n = 6), ciprofloxacin (n = 6), ofloxacin (n = 2), gatifloxacin (n = 2), norfloxacin (n = 1) and trovafloxacin (n = 1). Additionally, we retrieved ten case reports published in the literature involving non-ventilated patients administered ciprofloxacin (n = 4), levofloxacin (n = 2) and ofloxacin, norfloxacin, pefloxacin and prulifloxacin (1 patient each). Myasthenia gravis exacerbations developed a median of 1 day following fluoroquinolone exposure. The 37 cases describe dyspnoea (n = 19; 51%), myasthenic crisis requiring ventilatory support (n = 11; 30%) and death (n = 2; 5%). Additional exacerbation-related adverse events were generalized muscle weakness (n = 20; 54%), dysphagia (n = 9; 24%), diplopia (n = 6; 16%) and ptosis (n = 6; 16%). Six patients (16%) experienced a positive rechallenge, with recurrent myasthenia gravis exacerbation after fluoroquinolone reintroduction.
  
  
  CONCLUSIONS
  Fluoroquinolone exposure may result in potentially life-threatening myasthenia gravis exacerbations in patients with underlying disease. Healthcare professionals should be aware of this serious drug-disease association and carefully weigh the benefit-risks of fluoroquinolones when treating infections in non-ventilated myasthenic patients.
authors: US Food and Drug Administration, Center for Drug Evaluation and Research, Office of Surveillance and Epidemiology, Division of Pharmacovigilance II, Silver Spring, MD 20993, USA.
authors: S Christopher
authors: SC
authors: Jones
authors: Alfred
authors: A
authors: Sorbello
authors: Robert M
authors: RM
authors: Boucher
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D024841:Fluoroquinolones / Q000009:adverse effects*; D006801:Humans; D009157:Myasthenia Gravis / Q000139:chemically induced* / Q000503:physiopathology; D012189:Retrospective Studies; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones