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Metyrosine
Metirosine (International Nonproprietary Name, INN and British Approved Name, BAN; α-Methyltyrosine, Metyrosine United States Adopted Name, USAN, AMPT) is an antihypertensive drug. It inhibits the enzyme tyrosine hydroxylase and, therefore, catecholamine synthesis, which, as a consequence, depletes the levels of the catecholamines dopamine, adrenaline and noradrenaline in the body. It is available as a generic medication. Clinical use Metirosine has been shown to suppress catecholamine synthesis and alleviate symptoms related to catecholamine excess, including hypertension, headache, tachycardia, constipation, and tremor. Metirosine is primarily used to reduce these symptoms in patients with pheochromocytoma. It is contraindicated for the treatment of essential hypertension. Metirosine is used as an off-label treatment for DiGeorge syndrome. Metirosine is used in scientific research to investigate the effects of catecholamine depletion on behavior. There is evidence that cate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noradrenaline
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', "near", and '' ren'', "kidney") is more commonly used in the United Kingdom, whereas "norepinephrine" (from Ancient Greek ἐπῐ́ (''epí''), "upon", and νεφρός (''nephrós''), "kidney") is usually preferred in the United States. "Norepinephrine" is also the international nonproprietary name given to the drug. Regardless of which name is used for the substance itself, parts of the body that produce or are affected by it are referred to as noradrenergic. The general function of norepinephrine is to mobilize the brain and body for action. Norepinephrine release is lowest during sleep, rises during wakefulness, and reaches much higher levels during situations of stress or danger, in the so-called fight-or-flight response. In the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachycardia
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (such as with exercise) or abnormal (such as with electrical problems within the heart). Complications Tachycardia can lead to fainting. When the rate of blood flow becomes too rapid, or fast blood flow passes on damaged endothelium, it increases the friction within vessels resulting in turbulence and other disturbances. According to the Virchow's triad, this is one of the three conditions that can lead to thrombosis (i.e., blood clots within vessels). Causes Some causes of tachycardia include: * Adrenergic storm * Anaemia * Anxiety * Atrial fibrillation * Atrial flutter * Atrial tachycardia * Atrioventricular reentrant tachycardia * AV nodal reentrant tachycardia * Brugada syndrome * Circulatory shock and its various causes ( obstr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenethylamines
Substituted phenethylamines (or simply phenethylamines) are a chemical class of organic compounds that are based upon the phenethylamine structure; the class is composed of all the derivative compounds of phenethylamine which can be formed by replacing, or substituting, one or more hydrogen atoms in the phenethylamine core structure with substituents. The structural formula of any substituted phenethylamine contains a phenyl ring that is joined to an amino (NH) group via a two-carbon sidechain. Hence, any substituted phenethylamine can be classified according to the substitution of hydrogen (H) atoms on phenethylamine's phenyl ring, sidechain, or amino group with a specific group of atoms. Many substituted phenethylamines are psychoactive drugs which belong to a variety of different drug classes, including central nervous system stimulants (e.g., amphetamine), hallucinogens (e.g., dl- 2,5-dimethoxy-4-methylamphetamine DOM), entactogens (e.g., 3,4-methylenedioxyamphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antihypertensive Agents
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers. Which type of medication to use initially for hypertension has been the subject of several large studies and resulting national guidelines. The fundamental goal of treatment should be the prevention of the important endpoints of hypert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P-Chlorophenylalanine
Fenclonine, also known as ''para''-chlorophenylalanine (PCPA), acts as a selective and irreversible inhibitor of tryptophan hydroxylase, which is a rate-limiting enzyme in the biosynthesis of serotonin. It has been used experimentally to treat carcinoid syndrome, but the side effects, mostly hypersensitivity reactions and psychiatric disturbances, have prevented development for this use. The effects of serotonin depletion from fenclonine are so drastic that serotonin cannot even be detected immunohistochemically within the first day after administration of a control dose. Tryptophan hydroxylase activity can be detected neither in cell bodies or nerve terminals. After one week 10% of control values (the baseline extrapolated for the study) had replenished in the raphe nucleus, and after two weeks from initial treatment as much was again detected in the hypothalamus region. Aromatic L-amino acid decarboxylase (AADC) levels were at no time affected. It is used in scientific rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DiGeorge Syndrome
DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by a microdeletion on the long arm of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental delay, learning problems and cleft palate. Associated conditions include kidney problems, schizophrenia, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves' disease. DiGeorge syndrome is typically due to the deletion of 30 to 40 genes in the middle of chromosome 22 at a location known as ''22q11.2''. About 90% of cases occur due to a new mutation during early development, while 10% are inherited from a person's parents. It is autosomal dominant, meaning that only one affected chromosome is needed for the condition to occur. Diagnosis is suspected based on the symptoms and confirmed by genetic testing. Although there is no cure, treatment can improve symptoms. This often includes a m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Hypertension
Essential hypertension (also called primary hypertension, or idiopathic hypertension) is the form of hypertension that by definition has no identifiable secondary cause. It is the most common type affecting 85% of those with high blood pressure. The remaining 15% is accounted for by various causes of secondary hypertension. Primary hypertension tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Prevalence of essential hypertension increases with age, and individuals with relatively high blood pressure at younger ages are at increased risk for the subsequent development of hypertension. Hypertension can increase the risk of cerebral, cardiac, and renal events. Classification A recent classification recommends blood pressure criteria for defining normal blood pressure, prehypertension, hypertension (stages I and II), and isolated systolic hypertension, which is a common occurrence among the elderly. These readings ... [...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] |
Tremor
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the hands. In some people, a tremor is a symptom of another neurological disorder. A very common tremor is the teeth chattering, usually induced by cold temperatures or by fear. Types Tremor is most commonly classified by clinical features and cause or origin. Some of the better-known forms of tremor, with their symptoms, include the following: * Cerebellar tremor (also known as intention tremor) is a slow, broad tremor of the extremities that occurs at the end of a purposeful movement, such as trying to press a button or touching a finger to the tip of one's nose. Cerebellar tremor is caused by lesions in or damage to the cerebellum resulting from stroke, tumor, or disease such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypertension
Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high blood pressure, however, is 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 primary (essential) hypertension or secondary hypertension. About 90–95% of cases are primary, defined as high blood pressure due to nonspecific lifestyle and genetic factors. Lifestyle factors that increase the risk include excess salt in the diet, excess body weight, smoking, and alcohol use. The remaining 5–10% of cases are categorized as secondary high blood pressure, defined as high blood pressure due to an identifiable cause, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Headache
Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result of many conditions. There are a number of different classification systems for headaches. The most well-recognized is that of the International Headache Society, which classifies it into more than 150 types of primary and secondary headaches. Causes of headaches may include dehydration; fatigue; sleep deprivation; stress; the effects of medications (overuse) and recreational drugs, including withdrawal; viral infections; loud noises; head injury; rapid ingestion of a very cold food or beverage; and dental or sinus issues (such as sinusitis). Treatment of a headache depends on the underlying cause, but commonly involves pain medication (especially in case of migraine or cluster headache). A headache is one of the most commonly experienced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
