Preoperative Amlodipine Is More Efficacious Than Prazosin in Preventing Intraoperative Haemodynamic Instability in Pheochromocytoma/Paraganglioma Patients: Interim Analysis of a Pilot Randomized Controlled Study

Background: Preoperative blockade with α-blockers is recommended in patients with pheochromocytoma/paraganglioma (PPGL). The data on calcium channel blockade (CCB) in PPGL is scarce. We aim to compare the efficacy of CCB and α-blockers on intraoperative haemodynamic instability (HDI) in PPGL. Methods: In the interim analysis of this monocentric, pilot, open-label, randomized controlled trial, patients with solitary, secretory, and nonmetastatic PPGL were randomized to oral prazosin (maximum 30mg, n=9) or amlodipine (maximum 20mg, n=11). The primary outcomes were the episodes and duration of hypertension (SBP≥160mmHg) and hypotension (MAP