Amlodipine
In patients with renal insufficiency, calcium channel blockers like amlodipine are preferred antihypertensives as they do not adversely affect renal function and may even have a protective effect. Aliskiren is contraindicated in severe renal impairment. Thiazides (chlorthalidone) are less effective in renal insufficiency. Alpha-blockers like prazosin are not first-line agents.