What class of drugs should be administered to reduce blood pressure by decreasing contractility?

Calcium channel blockers are effective in reducing blood pressure primarily by causing vasodilation, which decreases peripheral resistance. However, they also play a critical role in decreasing contractility of the heart muscle itself. By blocking calcium influx into the cardiac and smooth muscle cells, these drugs lead to a reduction in the force of contraction of the heart (negative inotropic effect). This reduction in contractility contributes to lower cardiac output, which can further help in managing hypertension.

In contrast, diuretics primarily reduce blood pressure by decreasing blood volume through increased urine output, rather than directly affecting myocardial contractility. Positive inotropic drugs work to increase the contractility of the heart muscle, thereby increasing blood pressure rather than decreasing it. Beta-agonists, which activate beta-adrenergic receptors, also enhance contractility and can raise blood pressure due to their stimulatory effects on the heart. Thus, calcium channel blockers are the correct choice for decreasing contractility and subsequently lowering blood pressure.