REN and Hypertension: ,11 In light of these safety and efficacy concerns, renin-angiotensin system inhibitors (RASis) and calcium-channel blockers, which offer cardiovascular protection with fewer serious safety concerns, are used as first-line drugs for hypertension management in both patients treated with dialysis and the general population.12, 13, 14 α-Blockers have been generally reserved for use as add-on therapy for resistant or refractory hypertension.14