Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack. They are also widely used to treat high blood pressure, although they are no longer the first choice for initial treatment of most patients.
Propranolol, sold under the brand name Inderal among others, is a medication of the beta blocker class. It is used to treat high blood pressure, a number of types of irregular heart rate, thyrotoxicosis, capillary hemangiomas, performance anxiety, and essential tremors, as well to prevent migraine headaches, and to prevent further heart problems in those with angina or previous heart attacks. It can be taken by mouth or by injection into a vein. The formulation that is taken by mouth comes in short-acting and long-acting versions. Propranolol appears in the blood after 30 minutes and has a maximum effect between 60 and 90 minutes when taken by mouth.
Akathisia is a movement disorder characterized by a subjective feeling of inner restlessness accompanied by mental distress and an inability to sit still. Usually, the legs are most prominently affected. Those affected may fidget, rock back and forth, or pace, while some may just have an uneasy feeling in their body. The most severe cases may result in aggression, violence, and/or suicidal thoughts. Akathisia is also associated with threatening behaviour and physical aggression that is greatest in patients with mild akathisia, and diminishing with increasing severity of akathisia.
Hematidrosis, also called blood sweat, is a very rare condition in which a human sweats blood. The term is from Ancient Greek haîma/haímatos, meaning blood, and hīdrṓs, meaning sweat.
H2 antagonists, sometimes referred to as H2RAs and also called H2 blockers, are a class of medications that block the action of histamine at the histamine H2 receptors of the parietal cells in the stomach. This decreases the production of stomach acid. H2 antagonists can be used in the treatment of dyspepsia, peptic ulcers and gastroesophageal reflux disease. They have been surpassed by proton pump inhibitors (PPIs); the PPI omeprazole was found to be more effective at both healing and alleviating symptoms of ulcers and reflux oesophagitis than the H2 blockers ranitidine and cimetidine.
Sir James Whyte Black was a Scottish physician and pharmacologist. Together with Gertrude B. Elion and George H. Hitchings, he shared the Nobel Prize for Medicine in 1988 for pioneering strategies for rational drug-design, which, in his case, lead to the development of propranolol and cimetidine. Black established a Veterinary Physiology department at the University of Glasgow, where he became interested in the effects of adrenaline on the human heart. He went to work for ICI Pharmaceuticals in 1958 and, while there, developed propranolol, a beta blocker used for the treatment of heart disease. Black was also responsible for the development of cimetidine, an H2 receptor antagonist, a drug used to treat stomach ulcers.
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormally fast rhythms (tachycardias), such as atrial fibrillation, supraventricular tachycardia and ventricular tachycardia.
Antihypertensives are a class of drugs that are used to treat hypertension. 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.
Nadolol, sold under the brand name Corgard among others, is a medication used to treat high blood pressure, heart pain, atrial fibrillation, and some inherited arrhythmic syndromes. It has also been used to prevent migraine headaches and complications of cirrhosis. It is taken orally.
Labetalol is a medication used to treat high blood pressure and in long term management of angina. This includes essential hypertension, hypertensive emergencies, and hypertension of pregnancy. In essential hypertension it is generally less preferred than a number of other blood pressure medications. It can be given by mouth or by injection into a vein.
Bisoprolol, sold under the brand name Zebeta among others, is a beta blocker medication used for heart diseases. This includes high blood pressure, chest pain from not enough blood flow to the heart, and heart failure. It is taken by mouth.
Dichloroisoprenaline (DCI), also known as dichloroisoproterenol, was the first beta blocker ever to be developed. It is non-selective for the β1-adrenergic and β2-adrenergic receptors. DCI has low potency and acts as a partial agonist/antagonist at these receptors.
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.
A sympatholytic drug is a medication that opposes the downstream effects of postganglionic nerve firing in effector organs innervated by the sympathetic nervous system (SNS). They are indicated for various functions; for example, they may be used as antihypertensives. They are also used to treat anxiety, such as generalized anxiety disorder, panic disorder and PTSD. In some cases, such as with Guanfacine, they have also shown to be beneficial in the treatment of ADHD.
Cocaine intoxication refers to the subjective, desired and adverse effects of cocaine on the mind and behavior of users. Both self-induced and involuntary cocaine intoxication have medical and legal implications.
Diffuse neonatal hemangiomatosis (DNH) is a potentially fatal disorder where multiple benign (non-cancerous) blood vessel tumors (hemangiomas) are present in the skin and other organs. The mortality rate of diffuse neonatal hemangiomatosis is 50-90%. This disease is normally found in female Caucasian infants. The most common site of internal organ damage, or lesions, is the liver, which can redirect blood away from the heart and cause arteriovenous shunting. This can cause high cardiac output, leading to further complications such as congestive heart failure. This condition affecting the liver is also known as infantile hepatic hemangioma (IHH). Other sites of internal organ damage can include the intestines, nervous system, lungs, and sometimes the skeletal system. Early detection and treatment with steroids results in most newborn babies with this disease remaining healthy, with serious problems developing for some individuals during the hemangioma's growth phase.
β adrenergic receptor antagonists were initially developed in the 1960s, for the treatment of angina pectoris but are now also used for hypertension, congestive heart failure and certain arrhythmias. In the 1950s, dichloroisoproterenol (DCI) was discovered to be a β-antagonist that blocked the effects of sympathomimetic amines on bronchodilation, uterine relaxation and heart stimulation. Although DCI had no clinical utility, a change in the compound did provide a clinical candidate, pronethalol, which was introduced in 1962.
A hemangioma or haemangioma is a usually benign vascular tumor derived from blood vessel cell types. The most common form, seen in infants, is an infantile hemangioma, known colloquially as a "strawberry mark", most commonly presenting on the skin at birth or in the first weeks of life. A hemangioma can occur anywhere on the body, but most commonly appears on the face, scalp, chest or back. They tend to grow for up to a year before gradually shrinking as the child gets older. A hemangioma may need to be treated if it interferes with vision or breathing or is likely to cause long-term disfigurement. In rare cases internal hemangiomas can cause or contribute to other medical problems. The first line treatment option is beta blockers, which are highly effective in the majority of cases.
Adrenergic blocking agents are a class of drugs that exhibit its pharmacological action through inhibiting the action of the sympathetic nervous system in the body. The sympathetic nervous system(SNS) is an autonomic nervous system, in which we can not control by will. It triggers a series of responses after the body releases chemicals named noradrenaline and epinephrine. These chemicals will act on adrenergic receptors, with subtypes Alpha-1, Alpha-2, Beta-1, Beta-2, Beta-3, which ultimately allow the body to trigger a "fight-or-flight" response to handle external stress. These responses include vessel constriction in general vessels whereas there is vasodilation in vessels that supply skeletal muscles or in coronary vessels. Additionally, the heart rate and contractile force increase when SNS is activated, which may be harmful to cardiac function as it increases metabolic demand.
Robert Gray Robin Shanks CBE is a retired British clinical pharmacologist, specialising in Beta adrenergic blocking drugs. He was made a Commander of the Order of the British Empire (CBE) in the 1997 New Year Honours, For Services to Medicine.
