Renal dysfunction more likely in patients given ACE inhibitor and angiotensin-receptor blocker
MONDAY, March 21 (HealthDay News) -- Combination therapy of angiotensin-converting-enzyme (ACE) inhibitors and angiotensin-receptor blockers is often prescribed without established indications, and is associated with an elevated risk of adverse renal outcomes compared to monotherapy, according to a study published online March 21 in CMAJ, the journal of the Canadian Medical Association.
Finlay A. McAlister, M.D., of the University of Alberta in Edmonton, Canada, and colleagues investigated outcomes in 32,312 new users (mean age, 76.1 years) of either ACE inhibitors or angiotensin-receptor blockers, or a combination of the two between May 2002 and December 2006. Renal outcomes, incidence of hyperkalemia, and stopping treatment within six months of the initial prescription were compared between combination therapy and monotherapy.
The researchers found that, of the 1,750 patients prescribed combination therapy, 86.4 percent did not have trial-established indications. Patients given combination therapy were more likely to have renal dysfunction (adjusted hazard ratio [HR], 2.36) and hyperkalemia (adjusted HR, 2.42). Most patients only took the combination therapy for a median of three months before stopping at least one of the medications.
"Our most striking findings were that combination therapy was commonly prescribed for patients who did not have the trial-proven indications and that it was frequently stopped after only a few months, even when hyperkalemia or renal dysfunction did not occur," the authors write.
One author disclosed financial relationships with Amgen and Merck.