title: Evaluation of the concurrent use of potassium-influencing drugs as risk factors for the development of hyperkalemia.
abstract: BACKGROUND
  Hyperkalemia is a potentially dangerous electrolyte abnormality with a reported incidence of 1-10 % in hospitals. Patients are especially at risk of developing this complication if they use a combination of potassium supplements and potassium sparing diuretics or renin-angiotensin-aldosterone-system (RAAS) inhibitors. Previous studies on the occurrence of hyperkalemia in patients who use multiple potassium influencing drugs simultaneously were either small in sample size or did not investigate the full range of drugs involved.
  
  
  OBJECTIVE
  To assess the prevalence of hyperkalemia and to identify risk factors for its development in hospitalised patients using potassium supplements, potassium-sparing diuretics and/or RAAS-inhibitors concurrently.
  
  
  METHODS
  The study was conducted at the Onze Lieve Vrouwe Hospital in Amsterdam, The Netherlands from January 2009 to May 2010.
  
  
  METHODS
  A retrospective, nested case-control study included hospitalised patients who used a combination of potassium-influencing drugs. Cases were patients with serum potassium ≥ 5.5 mmol/l, controls were patients with normal serum potassium levels. Cases and controls were included in a ratio of 1:2. The following known risk factors associated with hyperkalemia were recorded and statistically analyzed: diabetes mellitus, congestive heart failure, decreased renal function, advanced age, gender and use of heparin, digoxin, non-steroidal anti-inflammatory drugs, beta-blockers, calcineurin antagonists and trimethoprim.
  
  
  METHODS
  Identify risk factors for the development of hyperkalemia as a result of the concurrent use of potassium supplements, RAAS inhibitors and/or potassium-sparing diuretics.
  
  
  RESULTS
  Of 774 patients included in this study, 52 patients developed hyperkalemia; a prevalence of 6.7 %. The only risk factor found to be significantly associated with hyperkalemia was lowered renal function, expressed as estimated glomerular filtration rate (eGFR) <50 ml/min (adjusted OR 5.08; 95 % CI 2.46-10.48). None of the other tested risk factors was identified as significant.
  
  
  CONCLUSIONS
  This study showed that decreased renal function (eGFR <50 ml/min) was associated with a fivefold increased risk for hyperkalemia in patients using potassium-influencing drugs. While previous studies showed that hyperkalemia substantially increases below a threshold of eGFR <30 or 40 ml/min, we observed a lower threshold of eGFR <50 ml/min. It is therefore recommended that physicians should be particularly alert while monitoring the use of potassium-influencing drugs in patients with decreased renal function.
authors: Department of Clinical Pharmacy, Zaans Medisch Centrum, Koningin Julianaplein 58, 1502 DV, Zaandam, The Netherlands, kuijvenhoven.m@zaansmc.nl.
authors: Marianne A
authors: MA
authors: Kuijvenhoven
authors: Eric A F
authors: EA
authors: Haak
authors: Kim B
authors: KB
authors: Gombert-Handoko
authors: Mirjam
authors: M
authors: Crul
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D004232:Diuretics / Q000009:adverse effects; D016903:Drug Monitoring / Q000379:methods; D005260:Female; D005919:Glomerular Filtration Rate; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D006947:Hyperkalemia / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011188:Potassium / Q000008:administration & dosage* / Q000097:blood; D015995:Prevalence; D051437:Renal Insufficiency / Q000150:complications* / Q000503:physiopathology; D012084:Renin-Angiotensin System / Q000187:drug effects; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D004232:Diuretics; D011188:Potassium
references: Emerg Med Clin North Am. 2005 Aug;23(3):723-47, viii-ix
references: 15982543
references: Intern Med. 2007;46(12):823-9
references: 17575373
references: N Engl J Med. 2004 Aug 5;351(6):543-51
references: 15295047
references: BMC Med Res Methodol. 2008 Jul 21;8:48
references: 18644127
references: J Clin Pharm Ther. 2005 Jun;30(3):233-9
references: 15896240
references: Br Med J (Clin Res Ed). 1983 Apr 9;286(6372):1189-92
references: 6404388
references: N Engl J Med. 2004 Aug 5;351(6):585-92
references: 15295051
references: Pharm World Sci. 2009 Jun;31(3):387-93
references: 19255869
references: N Engl J Med. 1994 Mar 31;330(13):877-84
references: 8114857
references: Am J Med. 2001 Apr 15;110(6):438-41
references: 11331054
references: Arch Intern Med. 1987 May;147(5):867-9
references: 3579440
references: Am J Med. 2009 Mar;122(3):215-21
references: 19272479
references: Arch Intern Med. 1998 Apr 27;158(8):917-24
references: 9570179