Pre-Operative Selective vs Non-Selective α-Blockade in Pheochromocytoma-Paraganglioma Patients Undergoing Surgery: A Meta-Analysis

The main objective of this systematic review and meta-analysis was to review, assess and report on the studies that have evaluated selective alpha blockade (SAB) vs. non-selective alpha blockade (NSAB) therapy in patients undergoing surgery for pheochromocytomas and paragangliomas (PPGL). We performed a systematic search of electronic databases. A meta-analysis was conducted to examine the effectiveness of the two blockades. RevMan 5.3 was used for the meta-analysis. Of the eight articles that met the inclusion criteria, there was only one randomized control trial. Meta-analysis showed that there was no significant difference between the groups SAB and NSAB with regard to intra-operative systolic blood pressure (SBP) >160 mm Hg (relative risk (RR) 0.95 [95% CI 0.57, 1.56] P = 0·83) and intra-operative vasopressor requirement (RR 1.10 [95% CI 0.96, 1.26] P = 0·16). Meta-analysis revealed that there was a significant difference between the groups (SAB vs NSAB) with respect to post-operative vasopressor requirement (RR 1.66 [95% CI 1.0, 2.74] P = 0·05). There was no significant difference between the groups with respect to post-operative complications (RR 0.84 [95% CI 0.58, 1.22] P = 0·36). In conclusion, as patients blocked selectively may have a higher incidence of vasodilator requirement intra-operatively, NSAB offers some haemodynamic advantage over SAB. However, NSAB's real clinical benefit cannot be ascertained with the current studies as this difference did not result in any significant advantage over SAB with regard to morbidity or mortality.

The evolution of alpha-blockers for the treatment of benign prostatic hyperplasia

Alpha-blockers have been evaluated for the treatment of benign prostatic hyperplasia (BPH) for 30 years, from early trials with the nonselective alpha-inhibitor phenoxybenzamine to short-acting (prazosin) then long-acting (terazosin, doxazosin, tamsulosin, alfuzosin) selective alpha(1)-antagonists. All of the alpha-blockers evaluated have demonstrated comparable effectiveness, and the evolution of alpha-blocker therapy for BPH has therefore focused primarily on improving convenience and tolerability. Although all of the long-acting alpha(1)-blockers are well tolerated, only tamsulosin and alfuzosin SR are administered without the requirement for dose titration. Alfuzosin has the additional advantage over tamsulosin of a lower incidence of ejaculatory dysfunction. Studies of subtype-selective alpha(1)-antagonists have not demonstrated superior efficacy or improved tolerability over the existing long-acting alpha(1)-blockers.