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Alpha Blocker
Alpha 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). Historically, alpha-blockers were used as a tool for pharmacologic research to develop a greater understanding of the autonomic nervous system. Using alpha blockers, scientists began characterizing arterial blood pressure and central vasomotor control in the autonomic nervous system. Today, they can be used as clinical treatments for a limited number of diseases. Alpha blockers can treat a small range of diseases such as hypertension, Raynaud's disease, benign prostatic hyperplasia (BPH) and erectile dysfunction. Generally speaking, these treatments function by binding an α-blocker to α receptors in the arteries and smooth muscle. Ultimately, depending on the type of alpha receptor, this relaxes the smooth muscle or blood vessels, which increases fluid flow in these entities. Classificat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertension
Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major risk factor for stroke, coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia. Hypertension is a major cause of premature death worldwide. High blood pressure is classified as essential hypertension, primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to non-specific lifestyle and Genetics, genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, overweight, excess body weight, smoking, physical inactivity and Alcohol (drug), alcohol use. The remaining 5–10% of cases are categorized as secondary hypertension, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erectile Dysfunction
Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a Human penis, penile erection with sufficient rigidity and duration for satisfactory sexual activity. It is the most common sexual problem in males and can cause psychological distress due to its impact on self-image and sexual relationships. The majority of ED cases are attributed to physical risk factors and predictive factors. These factors can be categorized as vascular, neurological, local penile, hormonal, and drug-induced. Notable predictors of ED include aging, cardiovascular disease, diabetes mellitus, Hypertension, high blood pressure, obesity, Dyslipidemia, abnormal lipid levels in the blood, hypogonadism, smoking, Depression (mood), depression, and Adverse drug reactions, medication use. Approximately 10% of cases are linked to psychosocial factors, encompassing conditions such as depressio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inverse Agonist
In pharmacology, an inverse agonist is a drug that binds to the same receptor as an agonist but induces a pharmacological response opposite to that of the agonist. A neutral antagonist has no activity in the absence of an agonist or inverse agonist but can block the activity of either; they are in fact sometimes called ''blockers'' (examples include alpha blockers, beta blockers, and calcium channel blockers). Inverse agonists have opposite actions to those of agonists but the effects of both of these can be blocked by antagonists. A prerequisite for an inverse agonist response is that the receptor must have a constitutive (also known as intrinsic or basal) level of activity in the absence of any ligand. An agonist increases the activity of a receptor above its basal level, whereas an inverse agonist decreases the activity below the basal level. The efficacy of a full agonist is by definition 100%, a neutral antagonist has 0% efficacy, and an inverse agonist has < 0% (i.e., n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prazosin
Prazosin, sold under the brand name Minipress among others, is a medication used to treat high blood pressure, symptoms of an enlarged prostate, and nightmares related to post-traumatic stress disorder (PTSD). It is an α1 blocker. It is a less preferred treatment of high blood pressure. Other uses may include heart failure and Raynaud syndrome. It is taken by mouth. Common side effects include dizziness, sleepiness, nausea, and heart palpitations. Serious side effects may include low blood pressure with standing and depression. Prazosin is a non-selective inverse agonist of the α1-adrenergic receptors. It works to decrease blood pressure by dilating blood vessels and helps with an enlarged prostate by relaxing the outflow of the bladder. How it works in PTSD is not entirely clear. Prazosin was patented in 1965 and came into medical use in 1974. It is available as a generic medication. In 2021, it was the 183rd most commonly prescribed medication in the United States, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doxazosin
Doxazosin, sold under the brand name Cardura among others, is a medication used to treat symptoms of benign prostatic hyperplasia (enlarged prostate), hypertension (high blood pressure), and post-traumatic stress disorder (PTSD). For high blood pressure, it is a less preferred option. It is taken by mouth. Common side effects include dizziness, sleepiness, swelling, nausea, shortness of breath, and abdominal pain. Severe side effects may include low blood pressure with standing, an irregular heart beat, and priapism. It is a selective Alpha-1 blocker, α1-adrenergic blocker in the quinazoline class of compounds. Doxazosin was patented in 1977 and came into medical use in 1988. It is available as a generic medication. In 2022, it was the 180th most commonly prescribed medication in the United States, with more than 2million prescriptions. Medical uses High blood pressure Doxazosin is usually added to other antihypertensive therapy such as calcium channel antagonists, diureti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfuzosin
Alfuzosin, sold under the brand name Uroxatral among others, is a medication of the α1 blocker class. It is used to treat benign prostatic hyperplasia (BPH). As an antagonist of the α1-adrenergic receptor, it works by relaxing the muscles in the prostate and bladder neck, making urination easier. Alfuzosin was patented in 1978 and approved for medical use in 1988. It was approved in the US for benign prostatic hyperplasia in 2003. In 2020, it was the 336th-most commonly prescribed medication in the United States, with more than 700thousand prescriptions. Side effects The most common side effects are dizziness (due to postural hypotension), upper respiratory tract infection, headache, fatigue, and abdominal disturbances. Side effects include stomach pain, heartburn, and congested nose. Adverse effects of alfuzosin are similar to that of tamsulosin, but with 70% lower rate of retrograde ejaculation. Chemistry Alfuzosin contains a stereocenter, so is chiral, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trazodone
Trazodone is an antidepressant medication used to treat major depressive disorder, anxiety disorders, and insomnia. It is a phenylpiperazine compound of the serotonin antagonist and reuptake inhibitor (SARI) class. The medication is taken orally. Common side effects include dry mouth, feeling faint, vomiting, and headache. More serious side effects may include suicide, mania, irregular heart rate, and pathologically prolonged erections. It is unclear if use during pregnancy or breastfeeding is safe. Trazodone also has sedating effects. Trazodone was approved for medical use in the United States in 1981. It is available as a generic medication. In 2022, it was the eighteenth most commonly prescribed medication in the United States, with more than 27million prescriptions. Medical uses Depression The primary use of trazodone is the treatment of unipolar major depression with or without anxiety. Data from open and double-blind trials suggest that the antidepressant eff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tolazoline
Tolazoline is a non-selective Competitive antagonist, competitive Alpha blocker#Classification, α-adrenergic receptor antagonist. It is a vasodilator that is used to treat spasms of peripheral blood vessels (as in acrocyanosis). It has also been used (in conjunction with sodium nitroprusside) successfully as an antidote to reverse the severe peripheral vasoconstriction which can occur as a result of overdose with certain 5-HT2A receptor, 5-HT2A receptor agonist drugs such as 25I-NBOMe, 2,5-Dimethoxy-4-bromoamphetamine, DOB, and Bromodragonfly. It is however most commonly used in veterinary medicine, to reverse xylazine-induced sedation. References {{Adrenergic receptor modulators Alpha-1 blockers Alpha-2 blockers Disulfiram-like drugs Imidazolines Vasodilators Veterinary drugs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phentolamine
Phentolamine, sold under the brand name Regitine among others, is a reversible nonselective α- adrenergic antagonist. Mechanism Its primary action is vasodilation due to α1 blockade. Non-selective α-blockers can cause a much more pronounced reflex tachycardia than the selective α1 blockers. Like the selective α1 blockers, phentolamine causes a relaxation of systemic vasculature, leading to hypotension. This hypotension is sensed by the baroreceptor reflex, which results in increased sympathetic nerve firing on the heart, releasing norepinephrine. In response, the β1 adrenergic receptors on the heart increase their rate, contractility, and dromotropy, which help to offset the decrease in systemic blood pressure. Unlike the α1 selective blockers, phentolamine also inhibits the α2 receptors, which function predominantly as presynaptic negative feedback for norepinephrine release. By abolishing this negative feedback phentolamine leads to even less regulated norepineph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenoxybenzamine
Phenoxybenzamine (PBZ, marketed under the trade names Dibenzyline and Dibenyline) is a non-selective, irreversible alpha blocker. Uses It is used in the treatment of hypertension, and specifically that caused by pheochromocytoma. It has a slower onset and a longer-lasting effect compared with other alpha blockers. It was also the first alpha blocker to be used for treatment of benign prostatic hyperplasia, although it is currently seldom used for that indication due to unfavourable side effects. It has been used in the treatment of hypoplastic left heart syndrome. It is also used in complex regional pain syndrome (CRPS) type 1 due to its antiadrenergic effects. It has shown to be beneficial if used in the first 3 months of the CRPS diagnosis. Investigational Phenoxybenzamine has long been known to block ejaculation without affecting semen quality or ability to achieve orgasm, which could make it an effective male contraceptive. This effect is completely reversible, and is bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-2 Adrenergic Receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi alpha subunit, Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-adrenergic, α2A-, α2B-adrenergic, α2B-, and α2C-adrenergic, α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central nervous system, central and peripheral nervous systems. Cellular localization The Alpha-2A adrenergic receptor, α2A adrenergic receptor is localised in the following central nervous system (CNS) structures: * Brainstem (especially the locus coeruleus as presynaptic & somatodendritic autoreceptor ) * Midbrain * Hypothalamus * Olfactory system * Hippocampus * Spinal cord * Cerebral cortex * Cerebellum * Septum Whereas the Alpha-2B adrenergic receptor, α2B adren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-2 Blocker
Alpha-2 blockers (or α2 blockers) are a subset of the alpha blocker class of drugs and are antagonists to the α2 adrenergic receptor. They are mainly used in research, having found limited clinical application in human medicine. They are extensively used in veterinary medicine to reverse the effects of alpha-2 agonist drugs used as sedatives, like xylazine, medetomidine and dexmedetomidine. Alpha-2 blockers increase noradrenaline release. Uses Yohimbine, historically used as an aphrodisiac, is sometimes used in veterinary medicine (although now largely replaced by atipamezole) for reversing the effects of α2s such as medetomidine that are used as sedatives during surgery. The tetracyclic antidepressants mianserin and mirtazapine are α2 blockers, although their efficacy as antidepressants may come from their activity at other receptor sites. Mechanistically, α2 blockers increase adrenergic, dopaminergic and serotonergic neurotransmitters and induce insulin secretion, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
