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Antihistamines
Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides relief from nasal congestion, sneezing, or hives caused by pollen, dust mites, or animal allergy with few side effects. Antihistamines are usually for short-term treatment. Chronic allergies increase the risk of health problems which antihistamines might not treat, including asthma, sinusitis, and lower respiratory tract infection. Consultation of a medical professional is recommended for those who intend to take antihistamines for longer-term use. Although people typically use the word "antihistamine" to describe drugs for treating allergies, doctors and scientists use the term to describe a class of drug that opposes the activity of histamine receptors in the body. In this sense of the word, antihistamines are subclassified according to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H1 Antagonist
H1 antagonists, also called H1 blockers, are a class of medications that block the action of histamine at the H1 receptor, helping to relieve allergic reactions. Agents where the main therapeutic effect is mediated by negative modulation of histamine receptors are termed antihistamines; other agents may have antihistaminergic action but are not true antihistamines. In common use, the term "antihistamine" refers only to H1-antihistamines. Virtually all H1-antihistamines function as inverse agonists at the histamine H1-receptor, as opposed to neutral antagonists, as was previously believed. Medical uses H1-antihistamines are clinically used in the treatment of histamine-mediated allergic conditions. These indications may include:Rossi S (Ed.) (2004). ''Australian Medicines Handbook 2004''. Adelaide: Australian Medicines Handbook. * Allergic rhinitis * Allergic conjunctivitis * Allergic dermatological conditions ( contact dermatitis) * Rhinorrhea (runny nose) * Urticar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hives
Hives, also known as urticaria, is a kind of skin rash with red, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and does not leave any long-lasting skin change. Fewer than 5% of cases last for more than six weeks. The condition frequently recurs. Hives frequently occur following an infection or as a result of an allergic reaction such as to medication, insect bites, or food. Psychological stress, cold temperature, or vibration may also be a trigger. In half of cases the cause remains unknown. Risk factors include having conditions such as hay fever or asthma. Diagnosis is typically based on the appearance. Patch testing may be useful to determine the allergy. Prevention is by avoiding whatever it is that causes the condition. Treatment is typically with antihistamines such as diphenhydramine and cetirizine. In severe cases, corticosteroids or leukotriene inhibitors may al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergic Rhinitis
Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose is usually clear. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. Some people may develop symptoms only during specific times of the year, often as a result of pollen exposure. Many people with allergic rhinitis also have asthma, allergic conjunctivitis, or atopic dermatitis. Allergic rhinitis is typically triggered by environmental allergens such as pollen, pet hair, dust, or mold. Inherited genetics and environmental exposures contribute to the development of allergies. Growing up on a farm and having multiple siblings decreases this risk. The underlying mechanism involves IgE antibod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HRH1
The H1 receptor is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled receptors. This receptor is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the heart, and in the central nervous system. The H1 receptor is linked to an intracellular G-protein (Gq) that activates phospholipase C and the inositol triphosphate (IP3) signalling pathway. Antihistamines, which act on this receptor, are used as anti-allergy drugs. The crystal structure of the receptor has been determined (shown on the right/below) and used to discover new histamine H1 receptor ligands in structure-based virtual screening studies. Function The expression of NF-κB, the transcription factor that regulates inflammatory processes, is promoted by the constitutive activity of the H1 receptor as well as by agonists that bind at the receptor. H1-antihistamines have been shown to attenuate NF-κB expression and mitigate cer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histamine
Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in 1910, it has been considered a local hormone ( autocoid) because it lacks the classic endocrine glands to secrete it; however, in recent years, histamine has been recognized as a central neurotransmitter. Histamine is involved in the inflammatory response and has a central role as a mediator of itching. As part of an immune response to foreign pathogens, histamine is produced by basophils and by mast cells found in nearby connective tissues. Histamine increases the permeability of the capillaries to white blood cells and some proteins, to allow them to engage pathogens in the infected tissues. It consists of an imidazole ring attached to an ethylamine chain; under physiological conditions, the amino group of the sid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allergies
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, coughing, a runny nose, shortness of breath, or swelling. Note: food intolerances and food poisoning are separate conditions. Common allergens include pollen and certain foods. Metals and other substances may also cause such problems. Food, insect stings, and medications are common causes of severe reactions. Their development is due to both genetic and environmental factors. The underlying mechanism involves immunoglobulin E antibodies (IgE), part of the body's immune system, binding to an allergen and then to a receptor on mast cells or basophils where it triggers the release of inflammatory chemicals such as histamine. Diagnosis is typi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H2 Receptor Antagonist
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. H2 antagonists are a type of antihistamine, although in common use the term "antihistamine" is often reserved for H1 antagonists, which relieve allergic reactions. Like the H1 antagonists, some H2 antagonists function as inverse agonists rather than receptor antagonists, due to the constitutive activity of these receptors. The prototypical H2 antagonist, called cimetidine, was developed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasal Congestion
Nasal congestion is the blockage of nasal breathing usually due to membranes lining the nose becoming swollen from inflamed blood vessels. Background In about 85% of cases, nasal congestion leads to mouth breathing rather than nasal breathing. According to Jason Turowski, MD of the Cleveland Clinic, "we are designed to breathe through our noses from birth—it's the way humans have evolved." This is referred to as " obligate nasal breathing." Nasal congestion can interfere with hearing and speech. Significant congestion may interfere with sleep, cause snoring, and can be associated with sleep apnea or upper airway resistance syndrome. In children, nasal congestion from enlarged adenoids has caused chronic sleep apnea with insufficient oxygen levels and hypoxia. The problem usually resolves after surgery to remove the adenoids and tonsils, however the problem often relapses later in life due to craniofacial alterations from chronic nasal congestion. Causes * Allergies, li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinusitis
Sinusitis, also known as rhinosinusitis, is inflammation of the mucous membranes that line the sinuses resulting in symptoms that may include thick nasal mucus, a plugged nose, and facial pain. Other signs and symptoms may include fever, headaches, a poor sense of smell, sore throat, a feeling that phlegm is oozing out from the back of the nose to the throat along with a necessity to clear the throat frequently and frequent attacks of cough. Generally sinusitis starts off as a common viral infection like common cold. This infection generally subsides within 5 to 7 days. During this time the nasal structures can swell and facilitate the stagnation of fluids in sinuses that leads to acute sinusitis which lasts from 6th day of the infection to 15th day. From the 15th day to 45th day of the infection comes the subacute stage followed by chronic stage. Whenever a chronic stage patient's immunity takes a hit the infection moves to "acute on sinusitis" stage and moves back to chro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmaceutical Drug
A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy ( pharmacotherapy) is an important part of the medical field and relies on the science of pharmacology for continual advancement and on pharmacy for appropriate management. Drugs are classified in multiple ways. One of the key divisions is by level of control, which distinguishes prescription drugs (those that a pharmacist dispenses only on the order of a physician, physician assistant, or qualified nurse) from over-the-counter drugs (those that consumers can order for themselves). Another key distinction is between traditional small molecule drugs, usually derived from chemical synthesis, and biopharmaceuticals, which include recombinant proteins, vaccines, blood products used therapeutically (such as IVIG), gene therapy, monoclonal antibodies and cell therapy (for instance, stem cell ... [...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. 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., negative) efficacy. Examples Receptors for which inverse agonists have been identified include the[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Antagonist
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins.Pharmacology Guide: In vitro pharmacology: concentration-response curves " '' GlaxoWellcome.'' Retrieved on December 6, 2007. They are sometimes called blockers; examples include alpha blockers, beta blocker [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
