I. Cetirizine Medication
Cetirizine medication (Cetirizine HCl) is an antihistamine, which helps block the action of histamine to help relieve you of your indoor and outdoor allergy symptoms. Cetirizine (Cetirizine HCl) is a prescription medicine that treats both indoor and outdoor allergy symptoms, as well as chronic hives. In fact, no other allergy medicine of its kind is approved to treat more allergies than Cetirizine medication . And studies show that 1 dose of Cetirizine works for a full 24 hours.
Cetirizine medication is also great for the whole family. It's the first antihistamine approved to treat indoor allergies in infants 6 months and up.
Most people who suffer from allergies have many symptoms.
Cetirizine medication helps relieve:
- Itchy, red, watery eyes
- Sneezing and runny, itchy nose
- Postnasal drip
- Itching from hives
Antihistamines: Information
Histamine is an important body chemical that is responsible for the congestion, sneezing, and runny nose that a patient suffers with an allergic attack or an infection.
Antihistamine drugs block the action of histamine, therefore reducing the allergy symptoms. For the best result, antihistamines should be taken before allergic symptoms get well established.
An allergy is a condition in which the body becomes unusually sensitive to some substance, such as pollen, mold spores, dust particles, certain foods, or medicines.
Common types of allergies
There are many kinds of allergies. Some of the most common types are:
- Indoor allergies - year-round, can be treated with medicine
- Outdoor allergies - seasonal, can be treated with medicine
These substances, known as allergens, cause no unusual reactions in most people. But in people who are sensitive to them, exposure to allergens causes the immune system to overreact. The main reaction is the release of a chemical called histamine from specialized cells in the body tissues. Histamine causes such familiar and annoying allergy symptoms as sneezing, itching, runny nose, and watery eyes.
As their name suggests, antihistamines block the effects of histamine, reducing allergy symptoms. When used for this purpose, they work best when taken before symptoms are too severe. Antihistamine creams and ointments may be used to temporarily relieve itching. Some antihistamines are also used to treat motion sickness, nausea, dizziness, and vomiting. And because some cause drowsiness, they may be used as sleep aids.
Histamines: Information
Histamine is an important
protein involved in many allergic reactions. Allergies are caused
by an immune response to a normally innocuous substance (i.e. pollen,
dust) that comes in contact with lymphocytes specific for that substance,
or antigen. In many cases, the lymphocyte triggered to respond is
a mast cell. For this response to occur, a free-floating IgE (an
immunoglobulin associated with allergic response) molecule specific
to the antigen must first be attached to cell surface receptors
on mast cells. Antigen binding to the mast cell-attached IgE then
triggers the mast cell to respond. This response often includes
the release of histamine.
The release of histamine
(hist = because it's made up of histidine residues, amine = because
it's a vasoactive amine) causes several allergic symptoms.
1) It contributes to an inflammatory response.
2) It causes constriction of smooth muscle.
Diagram: Histamine
(Explanation for diagram: As more of the allergen enters your body,
the antibodies "grab" the allergen. This triggers the
basophils and mast cells to release powerful chemicals, including
histamine.
Histamine can cause
inflammation directly as well as indirectly. Upon release of histamine
by an antigen activated mast cell, permeability of vessels near
the site is increased. Thus, blood fluids (including leukocytes,
which participate in immune responses) enter the area causing swelling.
This is accomplished due to histamine's
ability to induce phosphorylation of an intercellular adhesion protein
(called (VE)-cadherin) found on vascular endothelial cells. That
is why histamine is known
as being vasoactive. Gaps between the cells in vascular tissue are
created by this phosphorylation, allowing blood fluids to seep out
into extracellular space.
Indirectly, histamine
contributes to inflammation by affecting the functions of other
leukocytes in the area. It has been suggested by researchers that
histamine release triggers
the release of cytokines and inflammatory mediator by some neighboring
leukocytes. These chemicals in turn increase the inflammatory response.
Histamine's second type
of allergic response is one of the major causes for asthma. In response
to an allergen (a substance that triggers an allergic reaction),
histamine, along with
other chemicals, causes the contraction of smooth muscle. Consequently,
the muscles surrounding the airways constrict causing shortness
of breath and possibly complete trachial-closure, an obviously life-threatening
condition. If the effects
of histamine during an allergic reaction are inhibited, the
life of an allergic person can be eased (in the case of inflammation)
or even saved by preventing or shortening asthma attacks. Thankfully,
many effective drugs have been developed to hinder histamine's
allergic response activities.
Side effects of antihistamines
Common side effects of antihistamines include drowsiness, dizziness, poor coordination, restlessness, excitability, nervousness, and upset stomach. These problems usually go away as the body adjusts to the drug and do not require medical treatment. Less common side effects, such as dry mouth, nose, and eyes, irritability, difficulty urinating, and blurred vision, also may occur and do not need medical attention unless they do not go away or they interfere with normal activities.
If any of the following side effects occur, check with the physician who prescribed the medicine as soon as possible:
- Rapid, irregular, pounding, or fluttering heartbeat
- Convulsions
- Sweating
- Vomiting
- Fever
- Chills
- Fainting
- Breathing problems
- Hallucinations
- Unusual bleeding or bruising
- Low blood pressure
- Unusual sensitivity to light
- Uncontrolled movements.
Alternate Uses Of Antihistamines
- Motion sickness
- Vertigo (severe dizziness)
- Nausea and vomiting
- Stiffness and tremors in patients with Parkinson's disease (diphenhydramine)
- Cough due to colds or hay fever (the syrup form of diphenhydramine)
- Insomnia
- Pre-operative sedation
- With narcotic analgesics for severe pain
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II. Useful links
Government http://www.cdc.gov/
http://www.fda.gov/
http://www.fda.gov/cder/ogd/
http://www.nih.gov/
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi
http://www.health.gov.on.ca/
National Library of Medicine
World Health Organization
Health Sites
http://www.mayoclinic.com/index.cfm
MedicineNet.com
Drugdigest.org
Healthsquare.com
Pharmacy sites
http://www.entnet.org/healthinfo/allergies/antihistamines.cfm
http://www.hsforum.com/stories/storyReader$1509
Bio.davidson.edu
http://www.swedish.org/16714.cfm
http://www.hsforum.com/stories/storyReader$1504,
http://www.people.vcu.edu/~urdesai/atc.htm#Process%20of%20clotting
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