title: Quinine associated blindness.
abstract: BACKGROUND
  Quinine is commonly prescribed to the elderly for the treatment of benign nocturnal cramps, yet its use is not without complications.
  
  
  OBJECTIVE
  This article presents a case of quinine toxicity producing bilateral blindness, followed by a review of the adverse reactions associated with quinine use and its efficacy in treating benign nocturnal muscular cramps.
  
  
  CONCLUSIONS
  Visual loss has been associated with quinine serum concentrations above 10 microg/mL (therapeutic range 2-5 microg/mL). Other adverse reactions include neurological symptoms, haemolysis, acute renal failure and arrhythmia. There is conflicting evidence for the efficacy of quinine for leg cramps in randomised controlled studies, however, meta-analysis of these studies suggests some benefit. Although severe side effects are rare at therapeutic doses, the possibility of overdose needs to be considered when prescribing and an individual risk benefit analysis needs to be made. Benefits and adverse reactions should be closely monitored and medication ceased if appropriate.
authors.affiliation: Neurology Department, Gosford Hospital, New South Wales. btownend@doh.health.nsw.gov.au
authors.forename: Bradley Scott
authors.initials: BS
authors.lastname: Townend
authors.forename: Jonathan William
authors.initials: JW
authors.lastname: Sturm
authors.forename: Scott
authors.initials: S
authors.lastname: Whyte
mesh_terms: D001766:Blindness / Q000139:chemically induced*; D003975:Diazepam / Q000506:poisoning; D005194:Family Practice / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009125:Muscle Relaxants, Central / Q000009:adverse effects*; D011803:Quinine / Q000009:adverse effects*; D020922:Sleep-Wake Transition Disorders / Q000188:drug therapy; D013406:Suicide, Attempted; D016896:Treatment Outcome
chemical_list: D009125:Muscle Relaxants, Central; D011803:Quinine; D003975:Diazepam