Others, called beta-blockers, reduce the heart rate and the heart's output of blood. Another class of anti-hypertensives is called sympathetic nerve inhibitors.
Sympathetic nerves go from the brain to all parts of the body, including the arterioles.
They can cause the arteries to constrict or narrow, thereby raising blood pressure. This class of drugs reduces blood pressure by inhibiting these nerves from constricting blood vessels. Yet another group of drugs is the vasodilators. The ACE inhibitors interfere with the body's production of angiotensin, a chemical that causes the arterioles to constrict. The calcium antagonists can reduce the heart rate and relax blood vessels.