Renin-angiotensin system blockade and the risk of hyperkalemia in chronic hemodialysis patients.
BACKGROUND
Blockade of the renin-angiotensin system by angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers can cause hyperkalemia in patients with chronic renal insufficiency who are not on dialysis, but the risk of hyperkalemia in hemodialysis patients is unknown.


METHODS
We conducted a prospective study of 251 adult hemodialysis patients to determine if renin-angiotensin system blockade was associated with hyperkalemia, defined as a predialysis serum potassium concentration of 5.5 mmol/L or higher. Medication use was determined by chart review and patient interview. Predialysis serum potassium concentration was measured monthly.


RESULTS
There were 367 episodes of hyperkalemia during 1877 person-months of follow-up. After adjustment for potential confounding variables and for clustering of episodes by patient, use of an ACE inhibitor or an angiotensin receptor blocker was associated with a significantly higher risk of hyperkalemia (odds ratio [OR] = 2.2; 95% confidence interval [CI]: 1.4 to 3.4). The increased risk of hyperkalemia with renin-angiotensin system blockade was seen in anuric dialysis patients (OR = 2.3; 95% CI: 1.3 to 4.2), as well as those with residual renal function (OR = 2.1; 95% CI: 1.0 to 4.1).


CONCLUSIONS
The use of ACE inhibitors or angiotensin receptor blockers is independently associated with an increased risk of developing hyperkalemia in chronic hemodialysis patients. The serum potassium concentration should be closely monitored when these medications are prescribed for hemodialysis patients.
Knoll
Greg A
GA
Division of Nephrology, Department of Medicine, Kidney Research Centre, The Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
Sahgal
Arjun
A
Nair
Rama C
RC
Graham
Janet
J
van Walraven
Carl
C
Burns
Kevin D
KD
D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D006947:Hyperkalemia / Q000139:chemically induced*; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000628:therapy; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D006435:Renal Dialysis; D012084:Renin-Angiotensin System / Q000187:drug effects*; D012307:Risk Factors
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents