title: Patient- and physician-related risk factors for hyperkalaemia in potassium-increasing drug-drug interactions.
abstract: OBJECTIVE
  Hyperkalaemia due to potassium-increasing drug-drug interactions (DDIs) is a clinically important adverse drug event. The purpose of this study was to identify patient- and physician-related risk factors for the development of hyperkalaemia.
  
  
  METHODS
  The risk for adult patients hospitalised in the University Hospital Zurich between 1 December 2009 and 31 December 2011 of developing hyperkalaemia was correlated with patient characteristics, number, type and duration of potassium-increasing DDIs and frequency of serum potassium monitoring.
  
  
  RESULTS
  The 76,467 patients included in this study were prescribed 8,413 potentially severe potassium-increasing DDIs. Patient-related characteristics associated with the development of hyperkalaemia were pulmonary allograft [relative risk (RR) 5.1; p < 0.0001), impaired renal function (RR 2.7; p < 0.0001), diabetes mellitus (RR 1.6; p = 0.002) and female gender (RR 1.5; p = 0.007). Risk factors associated with medication were number of concurrently administered potassium-increasing drugs (RR 3.3 per additional drug; p < 0.0001) and longer duration of the DDI (RR 4.9 for duration ≥6 days; p < 0.0001). Physician-related factors associated with the development of hyperkalaemia were undetermined or elevated serum potassium level before treatment initiation (RR 2.2; p < 0.001) and infrequent monitoring of serum potassium during a DDI (interval >48 h: RR 1.6; p < 0.01).
  
  
  CONCLUSIONS
  Strategies for reducing the risk of hyperkalaemia during potassium-increasing DDIs should consider both patient- and physician-related risk factors.
authors.affiliation: Research Centre for Medical Informatics, Directorate of Research and Education, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland, emmanuel.eschmann@usz.ch.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Eschmann
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Beeler
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kaplan
authors.forename: Markus
authors.initials: M
authors.lastname: Schneemann
authors.forename: Gregor
authors.initials: G
authors.lastname: Zünd
authors.forename: Jürg
authors.initials: J
authors.lastname: Blaser
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003920:Diabetes Mellitus / Q000453:epidemiology; D004347:Drug Interactions; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000097:blood / Q000139:chemically induced* / Q000453:epidemiology*; D016040:Lung Transplantation; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D051437:Renal Insufficiency / Q000453:epidemiology; D012307:Risk Factors; D012737:Sex Factors; D013557:Switzerland / Q000453:epidemiology
chemical_list: D011188:Potassium