Risk of hyperkalemia associated with selective COX-2 inhibitors.
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.
Aljadhey
Hisham
H
Medication Safety Research Chair, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia. haljadhey@ksu.edu.sa
Tu
Wanzhu
W
Hansen
Richard A
RA
Blalock
Susan
S
Brater
D Craig
DC
Murray
Michael D
MD
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
D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D011188:Potassium