Vasodilator Therapy

Vasodilator therapy uses drugs that widen blood vessels by relaxing the smooth muscle in their walls, particularly in arteries and arterioles, lowering vascular resistance, reducing blood pressure and improving blood flow to tissue. These drugs act through several mechanisms, including hyperpolarization of vascular smooth muscle, cyclic AMP-mediated signaling and nitric oxide-dependent pathways, all of which lower intracellular calcium or reduce contraction of the muscle fibers lining the vessel wall. Vasodilators are used to treat hypertension, angina, congestive heart failure and erectile dysfunction, and a subclass, the phosphodiesterase-5 inhibitors, is also used to treat pulmonary arterial hypertension; vasodilator therapy has the opposite pharmacological effect of vasopressor therapy, which narrows blood vessels rather than widening them.