bronchoconstriction

An antihistamine is a drug which serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions, through action at the histamine receptor. Only 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-receptor antagonists, also known as HIncluding:

• Antihistamine - Pharmacology
• Antihistamine - Clinical use of antihistamines
• Antihistamine - Indications
• Antihistamine - Adverse drug reactions
• Antihistamine - First-generation H₁-receptor antagonists
• Antihistamine - Ethylenediamines
• Antihistamine - Ethanolamines
• Antihistamine - Alkylamines
• Antihistamine - Piperazines
• Antihistamine - Tricyclics
• Antihistamine - Common structural features of classical antihistamine
• Antihistamine - Second-generation H₁-receptor antagonists
• Antihistamine - Systemic
• Antihistamine - Topical
• Antihistamine - Common structural features of non-sedating antihistamines
• Antihistamine - Third-generation H₁-receptor antagonists
• Antihistamine - Systemic
• Antihistamine - Other agents
• Antihistamine - Inhibitors of histamine release
• Antihistamine - H₂-receptor antagonists
• Antihistamine - H₃- and H₄-receptor antagonists
• Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia - Antihistamine

An allergy or Type I hypersensitivity is an immune malfunction whereby a person's body is hypersensitised to react immunologically to typically nonimmunogenic substances. When a person is hypersensitised, these substances are known as allergens. The word allergy derives from the Greek words allos meaning "other" and ergon meaning "reaction" or "reactivity". Type I hypersensitivity is characterised by excessive activation of mast cells by immunoglobulin E resulting in a systemic inflammatory response that can resul ...

Including:

• Allergy - History
• Allergy - Signs and symptoms
• Allergy - Diagnosis
• Allergy - Skin test
• Allergy - Problems with skin test
• Allergy - Total IgE count
• Allergy - Treatment
• Allergy - Immunotherapy
• Allergy - Chemotherapy
• Allergy - Alternative therapies
• Allergy - Pathophysiology
• Allergy - Acute response
• Allergy - Late-phase response
• Allergy - Basis of the allergic response
• Allergy - Genetic Basis
• Allergy - Relationship with parasites
• Allergy - Basis of increasing prevalence
• Allergy - The hygiene hypothesis
• Allergy - Increasing use of chemicals
• Allergy - Common allergens

Read more here: » Allergy: Encyclopedia - Allergy

Acetylcholine (ACh) is a neurotransmitter extensively found in brain and autonomic nervous system. ACh is always used as the transmitter within the autonomic ganglion. Nicotinic receptors on the postganglionic neuron are responsible for the initial fast depolarisation (Fast EPSP) of that neuron. As a consequence of this, nicotinic receptors are often cited as the receptor on the postganglionic neurons at the ganglion. However, the subsequent hyperpolarisation (IPSP) and slow depolarisation (Slow EPSP) which represent the recove ...

See also:

Muscarinic acetylcholine receptor, Muscarinic acetylcholine receptor - Context, Muscarinic acetylcholine receptor - Physiology, Muscarinic acetylcholine receptor - The Form of Muscarinic Receptors, Muscarinic acetylcholine receptor - Variety of Receptor Forms, Muscarinic acetylcholine receptor - Receptor Subtype m1, Muscarinic acetylcholine receptor - m2, Muscarinic acetylcholine receptor - m3, Muscarinic acetylcholine receptor - m4, Muscarinic acetylcholine receptor - m5

Read more here: » Muscarinic acetylcholine receptor: Encyclopedia II - Muscarinic acetylcholine receptor - Physiology

There are limited mainstream medical treatments for allergies. Probably the most important factor in rehabilitation is the removal of sources of allergens from the home environment, and avoiding environments in which contact with allergens is likely. The trouble with them is that they have not all been proven. Therefore it could be seen as a placebo; however, it has helped people. See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Treatment

The body contains 21-28 grams of magnesium (1 mmol=2mEq=24.6 mg). Of this, 53% is located in bone, 19% in non-muscular tissue, and 1% in extracellular fluid. For this reason, blood levels of magnesium are not an adequate means of establishing the total amount of available magnesium. Most of the serum magnesium is bound to chelators, (i.e. ATP, ADP, proteins and citrate). Roughly 33% is bound to proteins, and 5-10% is not bound. This "free" magnesium is essential in regulating intracellular magnesium. Normal plasma Mg is 1.7-2.3 mg/dl (0.69-0.94 mmol/l). Of this 60% is free, 33% is bound to proteins, and less than 7% i ...

See also:

Hypomagnesemia, Hypomagnesemia - Homeostasis, Hypomagnesemia - Metabolism, Hypomagnesemia - Causes, Hypomagnesemia - Treatment, Hypomagnesemia - Arrhythmia, Hypomagnesemia - Obstetric, Hypomagnesemia - Electrolyte disturbances, Hypomagnesemia - Pulmonary

Read more here: » Hypomagnesemia: Encyclopedia II - Hypomagnesemia - Homeostasis

For symptomatic relief of carcinoid sydrome: Octreotide (somatostatin analogue- neutralizes serotonin and decreases urinary 5-HIAA) Methysergide maleate (antiserotonin agent but not used because of serious side effect of retroperitoneal fibrosis) Cyproheptadine (antihistamine) Alternative treatment for qualifying candidates: Surgical resection of tumo ...

See also:

Carcinoid syndrome, Carcinoid syndrome - Pathophysiology, Carcinoid syndrome - Diagnosis, Carcinoid syndrome - Treatment, Carcinoid syndrome - Prognosis, Carcinoid syndrome - Synonyms

Read more here: » Carcinoid syndrome: Encyclopedia II - Carcinoid syndrome - Treatment

There are limited mainstream medical treatments for allergies, probably the most important factor in rehabilitation is the removal of sources of allergens from the home environment, and avoiding environments in which contact with allergens is likely. The trouble with them is that they have not all been proven. Therefore it could be seen as a placebo, however it has helped people. See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Treatment

These are the oldest antihistaminergic drugs and are relatively inexpensive and widely available. They are effective in the relief of allergic symptoms, but are typically moderately to highly potent muscarinic acetylcholine receptor-antagonists (anticholinergic) agents as well. These agents also commonly have action at α-adrenergic receptors and/or 5-HT receptors. This lack of receptor-selectivity is the basis of the poor tolerability-profile of some of these agents, especially compared with the second-generation H1-antihistamines. Patient response and occurrence of a ...

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H₁-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H₁-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H₁-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H₂-receptor antagonists, Antihistamine - H₃- and H₄-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - First-generation H₁-receptor antagonists

Ipratropium has respiratory effects similar to atropine but since it is poorly absorbed into the blood, it has few side effects (such as tachycardia) at therapeutic doses. It is available under the trade names Alti-Ipratropium (AltiMed), Apo-Ipravent (Apotex), Atrovent Inhalation Aerosol (Boehringer Ingelheim), Atrovent Inhalation Solution (Boehringer Ingelheim), Atrovent Nasal Spray (Boehringer Ingelheim), Gen-Ipratropium (Genpharm), Novo-Ipramide (Novopharm), Nu-Ipratropium ...

See also:

Ipratropium, Ipratropium - Clinical uses, Ipratropium - Sources

Read more here: » Ipratropium: Encyclopedia II - Ipratropium - Clinical uses

There are limited mainstream medical treatments for allergies, probably the most important factor in rehabilitation is the removal of sources of allergens from the home environment, and avoiding environments in which contact with allergens is likely. Allergy - Immunotherapy. Hyposensitization is a form of immunotherapy where the patient is gradually vaccinated against progressively larger doses of the allergen in question. This can either reduce the severity or eliminate hypersensitivity altogether. It rel ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Treatment

There are several methods for the diagnosis and assessment of allergies. Allergy - Skin test. The typical and most simple method of diagnosis and monitoring of Type I Hypersensitivity is by skin testing, also known as prick testing, due to the series of pricks made into the patient's skin. Small amounts of suspected allergens and/or their extracts (pollen, grass, mite proteins, peanut extract, etc.) are introduced to sites on the skin marked with pen or dye (the ink/dye should be carefully selected, lest i ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Diagnosis

There has been a notable increase in the commonness of allergies in the past decades, and there are multiple hypotheses explaining this phenomenon. This is in part because we know what they are, in contrast to earlier humans who would think that it is a non-important illness. Allergy - The hygiene hypothesis. One theory that has been gaining strength is the "hygiene hypothesis". This theory maintains that since children in more affluent countries are leading a cleaner and cleaner life (less exposure to dir ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Basis of increasing prevalence

Allergy is characterised by a local or systemic inflammatory response to allergens. Local symptoms are: Nose: swelling of the nasal mucosa (allergic rhinitis) The distinctive behavior known as nasal salute, also known as allergy salute, is the habit of wiping of the nose in an upward direction due to itching. Eyes: redness and itching of the conjunctiva (allergic conjunctivitis) Airways: bronchoconstriction, wheezing and dyspnoea, sometimes outright attacks of asthma Skin: various rashes, such as eczema, hi ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Signs and symptoms

Magnesium deficiency is not uncommon in hospitalized patients. Elevated levels of magnesium (hypermagnesemia), however, are nearly always iatrogenic. 10-20% of all hospital patients, and 60-65% of patient in the intensive care unit (ICU) have hypomagnesemia. Hypomagnesiemia is underdiagnosed, as testing for serum magnesium levels is not routine. Hypomagnesemia results in increased mortality. Low levels of magnesium in your blood may mean either there is not enough magnesium in the diet, the intestines are not absorbing enough magnesiu ...

See also:

Hypomagnesemia, Hypomagnesemia - Homeostasis, Hypomagnesemia - Metabolism, Hypomagnesemia - Causes, Hypomagnesemia - Treatment, Hypomagnesemia - Arrhythmia, Hypomagnesemia - Obstetric, Hypomagnesemia - Electrolyte disturbances, Hypomagnesemia - Pulmonary

Read more here: » Hypomagnesemia: Encyclopedia II - Hypomagnesemia - Causes

Muscarinic acetylcholine receptors belong to a class of metabotropic receptors which use G proteins as their signalling mechanism. There are known to be a large number of these G-protein-coupled receptors for neuroreceptors, hormones, and other substances. G proteins are also present in taste, and odour detecting cells, in the retina, and in many other systems. In such receptors, the signalling molecule (the ligand) binds to a receptor which has seven transmembrane regions, in our case the ligand is ACh. This receptor is bound to intracellul ...

See also:

Muscarinic acetylcholine receptor, Muscarinic acetylcholine receptor - Context, Muscarinic acetylcholine receptor - Physiology, Muscarinic acetylcholine receptor - The Form of Muscarinic Receptors, Muscarinic acetylcholine receptor - Variety of Receptor Forms, Muscarinic acetylcholine receptor - Receptor Subtype m1, Muscarinic acetylcholine receptor - m2, Muscarinic acetylcholine receptor - m3, Muscarinic acetylcholine receptor - m4, Muscarinic acetylcholine receptor - m5

Read more here: » Muscarinic acetylcholine receptor: Encyclopedia II - Muscarinic acetylcholine receptor - The Form of Muscarinic Receptors

Treatment of hypomagnesemia depends on the degree of deficiency and the clinical effects. Oral replacement is appropriate for patients with mild symptoms, while intravenous replacement is indicated for patients with severe clinical effects. Intravenous magnesium sulphate (MgSO4) can be given in the following conditions: Hypomagnesemia - Arrhythmia. Magnesium is needed for the adequate function of the Na-K-ATPase pump in the heart. A lack of it depolarises and results in tachyarrythmia. Magnesium ...

See also:

Hypomagnesemia, Hypomagnesemia - Homeostasis, Hypomagnesemia - Metabolism, Hypomagnesemia - Causes, Hypomagnesemia - Treatment, Hypomagnesemia - Arrhythmia, Hypomagnesemia - Obstetric, Hypomagnesemia - Electrolyte disturbances, Hypomagnesemia - Pulmonary

Read more here: » Hypomagnesemia: Encyclopedia II - Hypomagnesemia - Treatment

All hypersensitivities result from an aberration somewhere in the normal immune process. The exact cause of such malfunctions is not always apparent, however, and several arguments from genetic-basis, environmental-basis and intermediate proponents exist with varying validity and acceptance. Allergy - Acute response. The difference between a type I hypersensitivity reaction against an allergen to the normal humoral response against a foreign body is that plasma cells secrete IgE as opposed to either IgM (a ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Pathophysiology

Allergy - Genetic Basis. There is much evidence to support the genetic basis of allergy, as allergic parents are more likely to have allergic children, and their allergies are likely to be stronger than those from non-allergic parents. However some allergies are not consistent along genealogies with parents being allergic to peanuts, but having children allergic to ragweed, or siblings not sharing the same allergens. Ethnicity has also been shown to play a role in some allergies. Interestingly, in r ...

See also:

Allergy, Allergy - History, Allergy - Signs and symptoms, Allergy - Diagnosis, Allergy - Skin test, Allergy - Problems with skin test, Allergy - Total IgE count, Allergy - Treatment, Allergy - Immunotherapy, Allergy - Chemotherapy, Allergy - Alternative therapies, Allergy - Pathophysiology, Allergy - Acute response, Allergy - Late-phase response, Allergy - Basis of the allergic response, Allergy - Genetic Basis, Allergy - Relationship with parasites, Allergy - Basis of increasing prevalence, Allergy - The hygiene hypothesis, Allergy - Increasing use of chemicals, Allergy - Common allergens

Read more here: » Allergy: Encyclopedia II - Allergy - Basis of the allergic response

Antihistamine - Indications. H1-antihistamines are clinically used in the treatment of histamine-mediated allergic conditions. Specifically, these indications may include: (Rossi, 2004) allergic rhinitis allergic conjunctivitis allergic dermatological conditions (contact dermatitis) urticaria angioedema pruritus (atopic dermatitis, insect bites) anaphylactic or anaphylactoid reactions - adjunct only nausea and vomiting (first-generation H1-antihistamines)

Antihistamine - Inhibitors of histamine release. These agents appear to stabilise the mast cells to prevent degranulation and mediator release. cromoglicate (cromolyn) nedocromil Antihistamine - H2-receptor antagonists. Main article: H2-receptor antagonist Clinically-relevant histamine H2-receptors are found principally in the parietal cells of the gastric mucosa. H2-receptor "antagonists" are also inve ...

See also:

Antihistamine, Antihistamine - Pharmacology, Antihistamine - Clinical use of antihistamines, Antihistamine - Indications, Antihistamine - Adverse drug reactions, Antihistamine - First-generation H₁-receptor antagonists, Antihistamine - Ethylenediamines, Antihistamine - Ethanolamines, Antihistamine - Alkylamines, Antihistamine - Piperazines, Antihistamine - Tricyclics, Antihistamine - Common structural features of classical antihistamine, Antihistamine - Second-generation H₁-receptor antagonists, Antihistamine - Systemic, Antihistamine - Topical, Antihistamine - Common structural features of non-sedating antihistamines, Antihistamine - Third-generation H₁-receptor antagonists, Antihistamine - Systemic, Antihistamine - Other agents, Antihistamine - Inhibitors of histamine release, Antihistamine - H₂-receptor antagonists, Antihistamine - H₃- and H₄-receptor antagonists, Antihistamine - Other agents with antihistaminergic activity

Read more here: » Antihistamine: Encyclopedia II - Antihistamine - Other agents