title: Risk of hyperkalemia associated with selective COX-2 inhibitors.
abstract: BACKGROUND
  Selective cyclooxygenase-2 (COX-2) inhibitors have been linked to cardiac death. The mechanism for this adverse effect appears to be by ischemic insult; however another mechanism could involve hyperkalemia. The objective of this study was to determine the effects of selective COX-2 inhibitors and non-selective nonsteroidal anti-inflammatory drugs (NSAIDs) on serum potassium concentration and the electrocardiogram.
  
  
  METHODS
  A retrospective cohort study was conducted using propensity score matching of patients from an inner-city academic medical center at Indianapolis, Indiana. Two hundred and two patients prescribed selective COX-2 inhibitors were matched to 202 patients prescribed non-selective NSAIDs using propensity scores methods. Outcomes included change in serum potassium concentration from baseline and the risk of an abnormal electrocardiogram.
  
  
  RESULTS
  Compared to patients prescribed non-selective NSAIDs, those prescribed a selective COX-2 inhibitor had a higher risk of serum potassium increase greater than 5 mEq/L (OR, 2.56; 95%CI, 1.03-6.36). However, patients prescribed selective COX-2 inhibitors had no greater risk of electrocardiogram abnormality (OR, 1.16; 95%CI, 0.74-1.82).
  
  
  CONCLUSIONS
  Selective COX-2 inhibitors may have a greater risk of hyperkalemia than non-selective NSAIDs. This study was exploratory with small numbers of patients. Further studies are needed to confirm these results and any association with cardiovascular events.
authors.affiliation: Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. haljadhey@ksu.edu.sa
authors.forename: Hisham
authors.initials: H
authors.lastname: Aljadhey
authors.forename: Wanzhu
authors.initials: W
authors.lastname: Tu
authors.forename: Richard A
authors.initials: RA
authors.lastname: Hansen
authors.forename: Susan
authors.initials: S
authors.lastname: Blalock
authors.forename: D Craig
authors.initials: DC
authors.lastname: Brater
authors.forename: Michael D
authors.initials: MD
authors.lastname: Murray
mesh_terms: D000046:Academic Medical Centers; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D016022:Case-Control Studies; D015331:Cohort Studies; D052246:Cyclooxygenase 2 Inhibitors / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000139:chemically induced* / Q000453:epidemiology; D007196:Indiana / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012189:Retrospective Studies
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D011188:Potassium