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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 norepinephrine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phentolamine Synthesis
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 norepinephrine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenergic Antagonist
An adrenergic antagonist is a drug that inhibits the function of adrenergic receptors. There are five adrenergic receptors, which are divided into two groups. The first group of receptors are the beta (β) adrenergic receptors. There are β1, β2, and β3 receptors. The second group contains the alpha (α) adrenoreceptors. There are only α1 and α2 receptors. Adrenergic receptors are located near the heart, kidneys, lungs, and gastrointestinal tract. There are also α-adreno receptors that are located on vascular smooth muscle. Antagonists reduce or block the signals of agonists. They can be drugs, which are added to the body for therapeutic reasons, or endogenous ligands. The α-adrenergic antagonists have different effects from the β-adrenergic antagonists. Pharmacology Adrenergic ligands are endogenous proteins that modulate and evoke specific cardiovascular effects. Adrenergic antagonists reverse the natural cardiovascular effect, based on the type of adrenorecepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravenous Therapy
Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use. The intravenous route is the fastest way to deliver medications and fluid replacement throughout the body as they are introduced directly into the circulatory system and thus quickly distributed. For this reason, the intravenous route of administration is also used for the consump ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheochromocytoma
Pheochromocytoma (PHEO or PCC) is a rare tumor of the adrenal medulla composed of chromaffin cells, also known as pheochromocytes. When a tumor composed of the same cells as a pheochromocytoma develops outside the adrenal gland, it is referred to as a paraganglioma. These neuroendocrine tumors are capable of producing and releasing massive amounts of catecholamines, metanephrines, or methoxytyramine, which result in the most common symptoms, including hypertension (high blood pressure), tachycardia (fast heart rate), and diaphoresis (sweating). However, not all of these tumors will secrete catecholamines. Those that do not are referred to as biochemically silent, and are predominantly located in the head and neck. While patients with biochemically silent disease will not develop the typical disease manifestations described above, the tumors grow and compress the surrounding structures of the head and neck, and can result in pulsatile tinnitus (ringing of the ear), hearing loss, au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex Regional Pain Syndrome
Complex regional pain syndrome (CRPS) is any of several painful conditions that are characterized by a continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or other lesion. Usually starting in a limb, it manifests as extreme pain, swelling, limited range of motion, and changes to the skin and bones. It may initially affect one limb and then spread throughout the body; 35% of affected people report symptoms throughout their whole bodies. Two types exist: reflex sympathetic dystrophy (RSD) and causalgia. Having both types is possible. Classification The classification system in use by the International Association for the Study of Pain (IASP) divides CRPS into two types. It is recognised that people may exhibit both types of CRPS. Signs and symptoms Clinical features of CRPS have been found to be neurogenic inflammation, inflammation resulting from the release of certain proinflammat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epinephrine
Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and by a small number of neurons in the medulla oblongata. It plays an essential role in the fight-or-flight response by increasing blood flow to muscles, heart output by acting on the SA node, pupil dilation response, and blood sugar level. It does this by binding to alpha and beta receptors. It is found in many animals, including humans, and some single-celled organisms. It has also been isolated from the plant ''Scoparia dulcis'' found in Northern Vietnam. Medical uses As a medication, it is used to treat several conditions, including allergic reaction anaphylaxis, cardiac arrest, and superficial bleeding. Inhaled adrenaline may be used to improve the symptoms of croup. It may also be used for asthma when other treatments are not e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasopressor
An antihypotensive agent, also known as a vasopressor agent or simply vasopressor, or pressor, is any substance, whether endogenous or a medication, that tends to raise low blood pressure. Some antihypotensive drugs act as vasoconstrictors to increase total peripheral resistance, others sensitize adrenoreceptors to catecholamines - glucocorticoids, and the third class increase cardiac output - dopamine, dobutamine. If low blood pressure is due to blood loss, then preparations increasing volume of blood circulation—plasma-substituting solutions such as colloid and crystalloid solutions (salt solutions)—will raise the blood pressure without any direct vasopressor activity. Packed red blood cells, plasma or whole blood should not be used solely for volume expansion or to increase oncotic pressure of circulating blood. Blood products should only be used if reduced oxygen carrying capacity or coagulopathy is present. Other causes of either absolute (dehydration, loss of plasma via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extravasation
__NOTOC__ Extravasation is the leakage of a fluid out of its container into the surrounding area, especially blood or blood cells from vessels. In the case of inflammation, it refers to the movement of white blood cells from the capillaries to the tissues surrounding them (leukocyte extravasation, also known as ''diapedesis''). In the case of malignant cancer metastasis it refers to cancer cells exiting the capillaries and entering organs (to form secondary tumors). It is frequently used in medical contexts, either referring to urine, or to blood. More specifically, it can refer to: * Extravasation (intravenous) * Extravasation of infusates * Extravasation of irrigation fluid * Extravasation of urine * Leukocyte extravasation * Angiopellosis (non-leukocyte cell extravastion) Extravasation of irrigation fluid Extravasation of irrigation fluid is the unintended migration of irrigation fluid (e.g. saline) introduced into a human body. This may occur in a number of types of endoscop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash Cart
A crash cart or code cart (crash trolley in UK medical jargon) or "MAX cart" is a set of trays/drawers/shelves on wheels used in hospitals for transportation and dispensing of emergency medication/equipment at site of medical/surgical emergency for life support protocols ( ACLS/ALS) to potentially save someone's life. The cart carries instruments for cardiopulmonary resuscitation and other medical supplies while also functioning as a support litter for the patient. The crash cart was originally designed and patented by ECRI Institute founder, Joel J. Nobel, M.D., while a surgical resident at Philadelphia's Pennsylvania Hospital in 1965. MAX helped enhance hospital's efficiency in emergencies by enabling doctors and nurses to save time, thereby increasing the chances of saving a life. The contents and organization of a crash cart vary from hospital to hospital, country to country, and specialty to specialty, but typically contain the tools and drugs needed to treat a person in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Channel Blocker
Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as medications to decrease blood pressure in patients with hypertension. CCBs are particularly effective against large vessel stiffness, one of the common causes of elevated systolic blood pressure in elderly patients. Calcium channel blockers are also frequently used to alter heart rate (especially from atrial fibrillation), to prevent peripheral and cerebral vasospasm, and to reduce chest pain caused by angina pectoris. N-type, L-type, and T-type voltage-dependent calcium channels are present in the zona glomerulosa of the human adrenal gland, and CCBs can directly influence the biosynthesis of aldosterone in adrenocortical cells, with consequent impact on the clinical treatment of hypertension with these agents. CCBs have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitroglycerin
Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, but the traditional name is retained. Invented in 1847 by Ascanio Sobrero, nitroglycerin has been used ever since as an active ingredient in the manufacture of explosives, namely dynamite, and as such it is employed in the construction, demolition, and mining industries. Since the 1880s, it has been used by militaries as an active ingredient and gelatinizer for nitrocellulose in some solid propellants such as cordite and ballistite. It is a major component in double-based smokeless propellants used by reloaders. Combined with nitrocellulose, hund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benzodiazepine
Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, insomnia, and seizures. The first benzodiazepine, chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955 and was made available in 1960 by Hoffmann–La Roche, who soon followed with diazepam (Valium) in 1963. By 1977, benzodiazepines were the most prescribed medications globally; the introduction of selective serotonin reuptake inhibitors (SSRIs), among other factors, decreased rates of prescription, but they remain frequently used worldwide. Benzodiazepines are depressants that enhance the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABAA receptor, resulting in sedative, hypnotic ( sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties. High doses o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
