This is because they can decrease vascular resistance and decrease pressure. Using α 1 selective antagonists, such as prazosin, has been efficacious in treating mild to moderate hypertension. Hypertension is due to an increase in vascular resistance and vasoconstriction.
Studies have also had great medical interest in testing alpha blockers, specifically α 2 blockers, to treat Type II diabetes and psychiatric depression. įurthermore, α-blockers can occasionally be used to treat anxiety and panic disorders, such as posttraumatic stress disorder (PTSD) induced nightmares. While there are limited clinical α-blocker uses, in which most α-blockers are used for hypertension or benign prostatic hyperplasia, α-blockers can be used to treat a few other diseases, such as Raynaud's disease, congestive heart failure (CHF), pheochromocytoma, and erectile dysfunction. Ĭan interfere with noradrenergic mechanisms. Lowers blood pressure, increases heart rate slightly. īlocks some α 1 receptor activity, but binds more strongly to β receptors. īlocks α 2 receptor, and increases norepinephrine release, thus increasing CNS activity. Posttraumatic stress disorder (PTSD) Ī blocker that has slight selectivity for α 1 receptors.Lowers blood pressure by decreasing peripheral resistance. Ĭompetitive blocking of α 1 and α 2 receptors.Ĥ hours of action after initial administration. Lowers blood pressure by decreasing peripheral resistance.īlocks alpha induced vasconstriction.
Nonselective covalent binding to α 1 and α 2 receptors. Selective α 2-adrenergic receptor antagonists include:įinally, the agents carvedilol and labetalol are both α and β-blockers.īelow are some of the most common drugs used in the clinic. Selective α 1-adrenergic receptor antagonists include: Non-selective α-adrenergic receptor antagonists include: However, the most common type of alpha blocker is usually an α 1 blocker. When the term "alpha blocker" is used without further qualification, it can refer to an α 1 blocker, an α 2 blocker, a nonselective blocker (both α 1 and α 2 activity), or an α blocker with some β activity. Classification Schematic of G Protein Coupled Receptor Signaling, representing Gi GPCR signaling, Gs GPCR signaling, and Gq GPCR signaling. Ultimately, depending on the type of alpha receptor, this relaxes the smooth muscle or blood vessels, which increases fluid flow in these entities. Generally speaking, these treatments function by binding an α-blocker to α receptors in the arteries and smooth muscle. Īlpha blockers can treat a small range of diseases such as hypertension, Raynaud's disease, benign prostatic hyperplasia (BPH) and erectile dysfunction. Today, they can be used as clinical treatments for a limited number of diseases. Using alpha blockers, scientists began characterizing arterial blood pressure and central vasomotor control in the autonomic nervous system. Historically, alpha-blockers were used as a tool for pharmacologic research to develop a greater understanding of the autonomic nervous system. Īlpha-blockers, also known as α-blockers or α-adrenoreceptor antagonists, are a class of pharmacological agents that act as antagonists on α-adrenergic receptors ( α-adrenoceptors). Image from Basic and Clinical Pharmacology by Bertram Katzung, et al. Specific locations and functions of the α receptors. Class of pharmacological agents Alpha blockers
0 kommentar(er)
