Dialysis and Beta Blockers Are Not Always a Good Match

Lara C. Pullen, PhD

October 31, 2014

Patients receiving chronic hemodialysis may be at a significantly higher risk for death if they are prescribed beta blockers with a high dialyzability (atenolol, acebutolol, or metoprolol) compared with beta blockers with a low dialyzability (bisoprolol or propranolol).

Matthew A. Weir, MD, from University Hospital in London, Ontario, Canada, and colleagues published the results of their propensity-matched, population-based retrospective cohort study online October 30 in the Journal of the American Society of Nephrology. They used health administrative data to determine exposure and outcome in patients older than 66 years.

Each group included 3294 patients. The study did not include a control group (patients not prescribed beta blockers).

Beta blockers are commonly prescribed to patients undergoing hemodialysis to decrease the risk for sudden cardiac death. The vast majority of randomized controlled trials of beta blockers have been performed in nondialysis patient populations.

Thus, beta blocker literature has rarely considered the extent to which hemodialysis might remove a beta blocker from circulation. Specifically, no studies have examined the effects of beta blocker dialyzability on outcomes in patients undergoing dialysis.

The investigators addressed this question in the current study through examination of the records of patients receiving chronic hemodialysis. Those prescribed a high-dialyzability beta blocker had a significantly higher risk for death in the following 180 days than those prescribed a low-dialyzability beta blocker (relative risk, 1.4; 95% confidence interval, 1.1 - 1.8; P = .006).

Although they categorized beta blockers simply into high- and low-dialyzability categories, the authors acknowledge that the pharmacokinetics of beta blockers are complicated: "[W]e recognize that the dialyzability of a drug is a complex interaction among many aspects of its pharmacokinetics and the dialysis prescription. Although a drug's volume of distribution, molecular weight and protein binding are readily available, the literature lacks data on factors such as the degree [of] red blood cell binding and changes in hepatic metabolism," the authors write.

The investigators also point out that bisoprolol has a high degree of beta-1 selectivity, which might play a role in its superior safety profile in the dialysis population.

"There's always been this inappropriate lumping together of beta blockers as a class," explained Charles A. Herzog, MD, from the Division of Cardiology, Department of Medicine, Hennepin County Medical Center and University of Minnesota, and the Chronic Disease Research Group, Minneapolis Medical Research Foundation in Minneapolis, to Medscape Medical News. Dr Herzog coauthored an accompanying editorial, along with Gautam R. Shroff, MD, from the Division of Cardiology, Department of Medicine, Hennepin County Medical Center and University of Minnesota. Although he does not think the study results should actually change clinical practice dramatically, Dr Herzog does feel the study should prompt deeper investigation into the differences between beta blockers.

The study authors, as well as Dr Herzog, note that the current study did not evaluate carvedilol. Although carvedilol is an important beta blocker for patients receiving hemodialysis, and the one Dr Herzog would recommend, it was not included in the study because access to the medication is restricted in the study jurisdiction.

The Canadian Institute of Health Research funded this project. The authors and Dr Herzog have disclosed no relevant financial relationships.

J Am Soc Nephrol. Published online October 30, 2014. Article abstract

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....