3 Adrenergic receptor antagonist conditions

Agonists as well as antagonists of (3-adienergic receptors are used for the treatment of a variety of conditions. (3-Adrenergic receptor antagonists belong to the most frequently used classes of dtugs. 

Rarely, bladder ontlet obstmction may be caused by a functional obstmction at the level of the bladder neck. Hypertrophy of the smooth mnscle fibers at the level of the bladder neck in men and women may result in obstruction to the flow of nrine. In those patients who fail pharmacologic therapy with a-adrenergic receptor antagonists, endoscopic incision using the cy stoscope is highly effective in treating this very nncommon condition. 

P receptor antagonists do not usually cause salt and water retention, and diuretic administration is not necessary to avoid edema or the development of tolerance. However, diuretics do have additive antihypertensive effects when combined with /5 blockers. The combination of a /5 receptor antagonist, a diuretic, and a vasodilator is effective for patients who require a third drug. /5 Adrenergic receptor antagonists are preferred drugs for hypertensive patients with conditions such as myocardial infarction, ischemic heart disease, or congestive heart failure. 

Catechol (22) was treated with 2-chloroacrylonitrile in basic conditions Michael addition to one OH group followed by a Williamson s reaction onto the other gave the nitrile (23) which was elaborated on to idazoxan (24) Scheme 5.7.) [14, 15]. It is claimed to be one of the most potent and selective a2-adrenergic receptor antagonists [16-19], Idazoxan shows unusual differential binding to a2-adrenoreceptors of different species [20]... 

Alpha-adrenergic antagonists are used primarily as antihypertensive drugs because of their ability to block vascular alpha-1 receptors. Beta-adrenergic antagonists (beta blockers) are administered primarily for their inhibitory effects on myocardial function and are used in the prevention and treatment of hypertension, angina pectoris, arrhythmias, and myocardial reinfarction. Many of the drugs introduced in this chapter are discussed further in chapters that deal with the specific clinical conditions (e.g., hypertension, asthma, and other disorders). 

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