Hi, both Atenolol & Lisinopril are used to control hypertension (high BP). Atenolol acts through the following mechanisms 1. it reduces heart rate, 2. it reduces cardiac output, 3. it reduces renin secretion (renin is responsible for increased BP by causing constriction of blood vessels). Long term administration also results in dilatation of smaller blood vessels further contributing to fall in BP. The advantages of Atenolol are 1. it does not cause sudden fall in BP ( postural hypotension). 2. longer duration of action & more suitable for young people. 3. increase survival rate & prevents stroke in people with high BP. Lisinopril is the first choice of antihypertensive drug. it acts by, 1. blocking the conversion of angiotensin 1 to angiotensin 2. Angiotensin increases cardiac contractility (contraction of heart muscles) & increases BP. 2. reducing aldosterone production (synthesis). Aldosterone increases sodium & water retention thus contributing to high BP. 3. increasing bradykinin level. Bradykinin causes dilatation of smaller blood vessels resulting in fall in BP. Advantages of Lisinopril are; 1. no sudden fall in BP. 2. safe in patients with diabetes, asthma & heart disease. improves blood flow to kidneys. 3. better quality of life as compared with other drugs used in high BP. Suitable in young people. Combination of Atenolol with Lisinopril is useful because, Lisinopril increases plasma renin activity which is overcome by Atenolol as it blocks renin release. This combination increases the efficacy of Lisinopril by 90%. This combination will definitely improve your performance.