• Robert G Badgett, Valerie A Lawrence, and Steven L Cohn.
• Department of Medicine, University of Texas Health Science Center at San Antonio, and Audie L. Murphy Memorial Veterans Affairs Hospital, San Antonio, Texas, USA. rbadgett@kumc.edu
• Anesthesiology. 2010 Sep 1; 113 (3): 585-92.

BackgroundRandomized controlled trials and meta-analyses provide conflicting guidance on the role of beta-adrenergic receptor blockers (beta-blockers) in reducing perioperative complications. We hypothesize that variability in trial results may be due in part to heterogeneous properties of beta-blockers. First, we propose that the extent of beta-blocker metabolism by cytochrome P-450 and the time available to titrate the dosage before surgery (titration time) may interact; dependence on P-450 may be most harmful when titration time is short. Second, beta-blockers vary in their selectivity for the beta-1 receptor and reduced selectivity may contribute to cerebral ischemia.MethodsWe used meta-analysis and meta-regression of existing trials to explore the role of these pharmacological properties.ResultsWe found that both of these pharmacological factors are significantly associated with reduced efficacy of beta-blockers.ConclusionsPharmacological properties of beta-blockers may contribute to heterogeneous trial results. Many trials have used metoprolol, which is extensively metabolized by cytochrome P450 and is less selective for the beta-1 receptor. For these two reasons, the efficacy of metoprolol to prevent perioperative cardiac complications should be compared with the efficacy of other beta-blockers.

16 keywords...

hide…