Alpha Adrenergic Antagonist
- Alpha adrenergic antagonists, also known as alpha blockers, bind alpha adrenergic receptors and prevent downstream signaling. These drugs have profound effects on the cardiovascular system primarily by blocking alpha1 receptors, reducing baseline sympathetic vasoconstrictive tone and thus yielding systemic vasodilation.
- Alpha1 blockers can be classified according to their receptor specificity. Older, non-specific antagonists, including phenxoybenzamine and phentolamine, in addition to alpha1 blockade also antagonize alpha2 receptors and have more limited clinical utility. Newer, specific antagonists have much more specificity for alpha1 receptors and tend to end in the suffix -zosin (i.e. terazosin, prazosin, etc).