The drug acts on the renin-angiotensin system in two ways to decrease total peripheral resistance.

Blood pressure depends on total peripheral resistance and cardiac output.

Thus, small arteries and arterioles are the main regulators of Total peripheral resistance.

This may, however, worsen hypertension by increasing the peripheral vascular resistance.

Reduction in number or density of capillaries may also contribute to peripheral resistance.

These substances are normally involved in controlling heart rate, force of cardiac contraction and peripheral resistance.

An increase in blood pressure can be caused by increased cardiac output, increased total peripheral resistance, or both.

Cardiac output and peripheral resistance are the two determinants of arterial pressure.

This helps restore blood pressure but also increases the total peripheral resistance, increasing the workload of the heart.

Blood pressure is dependent upon two factors: cardiac output and peripheral resistance.