placebo + losartan or lisinopril

This refers to a combination regimen in which a patient receives either placebo plus losartan or placebo plus lisinopril, but not both active drugs together. Losartan is an angiotensin II receptor blocker (ARB) that lowers blood pressure by blocking the action of angiotensin II at its receptor, leading to vasodilation. Lisinopril is an angiotensin-converting enzyme (ACE) inhibitor that reduces blood pressure by inhibiting the conversion of angiotensin I to angiotensin II, thereby decreasing vasoconstriction and aldosterone secretion. Both are used primarily for hypertension and related cardiovascular conditions[3][5][6][8][10]. Placebo is an inactive substance used as a control in clinical trials.