<<|>> ANTIHISTAMINES <<|>>
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DEFINITION

An Antihistamine is an agent that serves to inhibit the release or action of histamine. Antihistamine can be used to describe any histamine antagonist, but it is usually reserved for the classical antihistamines that act upon the H1 histamine receptor.

Antihistamines are used as treatment for allergies. Allergies are caused by an excessive response of the body to allergens, such as the pollen released by grasses and trees. An allergic reaction indicates an excessive release, by the body, of histamines. Other uses of antihistamines are to help with normal symptoms of insect stings even if there is no allergic reaction.


CLINICAL INDICATIONS


Vasomotor rhinitis - is not caused by an infection or allergy. The exact cause is unknown. Symptoms are triggered by something that irritates the nose, such as a dry atmosphere, air pollution, spicy foods, alcohol, strong emotions, or certain medications.

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Allergic conjunctivitis - is inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ between patients, the most common cause is hay fever. Symptoms consist of redness (mainly due to vasodilation of the peripheral small blood vessels), oedematching and increased lacrimation (production of tears). If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis.

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Anaphylactic reaction - is an acute systemic (multi-system) and severe type 1 hypersensitivity allergic reaction in humans and other mammals. The term comes from the Greek words ανα anaphylaxis (protection). Minute amounts of allergens may cause a life-threatening anaphylactic reaction. Anaphylaxis may occur aft - is inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ between patients, the most common cause is hay fever. Symptoms consist of redness (mainly due to vasodilation of the peripheral small blood vessels), oedematching and increased lacrimation (production of tears). If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis.

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H1-receptor antagonists

In common use, the term antihistamine refers only to H1 antagonists, also known as H1 antihistamines. It has been discovered that these H1-antihistamines are actually inverse agonists at the histamine H1-receptor, rather than antagonists per se. Clinically, H1 antagonists are used to treat allergic reactions.
Drugs
Brand Name
Specific Class
Side Effects
Dosage Forms
Contraindications
Pregnancy Category
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Benadryl
Allerin AH
Biogenerics
Caladryl

aminoalkyl ethers
CVS and CNS effects, previous allergy, GI disturbance
Capsule,
Syrup,
IV,
IM

Premature & newborn infants; asthma attack; lactation.
B
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Claritin
Allerta
Allerclear
Claricort
Clarinase

systemic sympatho
mimetic prepara
tions

Drowsiness, headache, psychomotor impairment, and antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastrointestinal disturbances
Tablets,
Oral Suspension, Syrup

Hepatic Diseases, renal impairment
B
Meclizinebonamine
Bonamine
Postadoxine

piperazine
Drowsiness; dry mouth; fatigue; vomiting; blurred vision
Tablet,
Chewable Tablet

Glaucoma or prostatic enlargement; pregnancy; asthma
B
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Atarax
MB Hydroxyzine

iphenyl-
methane derivatives anxiolytics

Drowsiness, sedation, somnolence, dry mouth
Tablet,
Syrup

Pregnancy and lactation
Previous hypersensitivity

C
Desloratadineclarinex.jpg
Claramax
Clarinex
Aerius

other
agents
used as systemic antihista
mines.

Fatigue, dry mouth, headache, gastrointestinal disturbances
Tablet,
Syrup

Nursing mothers
N/A
(Not have been studied for pregnant women)

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Cetimin
Cholergan
Virlix
Zyrtec

piperazine
weakness, problems with vision, confussion, dizzines
Tablet
Chewable tablet
Syrup

Hypersensitivity, lactation
B
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Antamin
Colvan
Dynatussin
Decolgen
Histacort


Drowsiness, dry mouth, nose, and throat, nausea, vomiting, loss of appetite, constipation, headache, increased chest congestion
Tablet,
Capsule,
Chewable Tablet,
Liquid

Hypersensitivity,
B
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Pharmasan
Thaprozine
Zinmet

phenothiazine derivatives
Blurred vision; dizziness; drowsiness; dry mouth; nausea; vomiting.
Tablet
Ampule
Suppository
Syrup

Hypersensitivity, coma, porphyria, cardiac disease, hypokalaemia
C
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Xyzal
piperazine
Sleepiness, headache. lightheadedness, mouth dryness, vision problems (blurred vision), palpitations and fatigue.
Tablet
Hypersensitivity
N/A




61F64-antihistamine.gif (Noun) (external image abreve.gifnexternal image lprime.giftexternal image emacr.gif-hexternal image ibreve.gifsexternal image prime.giftexternal image schwa.gif-mexternal image emacr.gifnexternal image lprime.gif) antihistamine - a medicine used to treat allergies and hypersensitive reactions and colds; works by counteracting the effects of histamine on a receptor site.


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Group Members:
Garcia
Carlos
Fernandez
Tamondong


MWF 9:30-10:30 A-206


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