Effects of an ACE inhibitor or angiotensin receptor blocker on potassium in CAPD patients.
BACKGROUND
Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) have shown numerous benefits to the cardiovascular system. However, using both drugs is associated with hyperkalemia, especially in end-stage renal disease (ESRD) patients. To the authors' knowledge, there has been no prospective systematic study of the safety and potassium homeostasis of both drugs in continuous ambulatory peritoneal dialysis (CAPD) patients.


METHODS
Twenty-nine stable, normokalemic CAPD patients without potassium-interference drugs were selected randomly to receive, for 4-week periods, 8 mg candesartan or 10 mg enalapril daily. After completion of the initial drug, both treatment groups were crossed.


RESULTS
Twenty-one patients completed the study. Baseline blood pressure, serum potassium level, plasma aldosterone, adequacy of dialysis, and residual renal function were not different between both groups. For the total group, serum potassium changes were not significantly different between baseline and at 4 weeks after treatment in both groups. The incidence of hyperkalemia (potassium > or =5.5 mEq/L [mmol/L]) was 13% and not different between groups. Nine of 11 events of hyperkalemia were associated with Kt/V urea less than 2, and 8 of 11 had low or low-average peritoneal equilibrium tests.


CONCLUSIONS
In ESRD patients on CAPD, the standard dose of ACE inhibitor, enalapril, or ARB, candesartan,has little effect on serum potassium, despite drops of plasma aldosterone observed. Both drugs should be considered in CAPD patients with hypertension or cardiovascular complications. However, use of both drugs requires caution in patients with inadequate dialysis or low solute transporters, and dietary noncompliant patients as well.
Phakdeekitcharoen
Bunyong
B
Division of Nephrology, Department of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. RABPD@mucc.mahidol.ac.th
Leelasa-nguan
Pornthep
P
D000328:Adult; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D001562:Benzimidazoles / Q000627:therapeutic use*; D001713:Biphenyl Compounds; D018592:Cross-Over Studies; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006706:Homeostasis; D006801:Humans; D006947:Hyperkalemia; D007676:Kidney Failure, Chronic / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010531:Peritoneal Dialysis, Continuous Ambulatory; D011188:Potassium / Q000097:blood*; D013777:Tetrazoles / Q000627:therapeutic use*
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D013777:Tetrazoles; D004656:Enalapril; D011188:Potassium; C081643:candesartan