If you're looking for effective over-the-counter (OTC) anti-allergy medicines, you must be looking for Zyrtec. Zyrtec is a tried and tested anti-allergy medication that is equally effective indoors and outdoors.

When the human body encounters tiny allergenic substances, such as dust and pollen, it releases histamines - a natural chemical that irritates the nasal passages and causes a reaction called allergic rhinitis. Hay fever is a common form of allergic rhinitis; it is seasonal and its onset can be predicted in many cases. Antihistamines such as the cetirizine HCI in Zyrtec work by blocking H1 histamine receptors and tempering inflammations.

Zyrtec is also known as cetirizine hydrochloride, or cetirizine HCI. This compound is manufactured by the Union Chimique Belge (UCB), which is based in Brussels, Belgium. Cetirizine HCI is marketed under several brand names, including Zirtec (Italy), Zyrlex in many European countries, Virlix in Mexico and some parts of Europe, Cetirizina MERCK in Spain, and Benadryl Once a Day in the United Kingdom. Zyrtec is the recognized brand name in Belgium, the United States, Australia, Hungary, Portugal, Finland, Poland and Romania. This drug comes in a rectangular shape with rounded-off edges. It is white and film-coated, and it comes in 5 mg and 10 mg strengths.

Cetirizine HCI is considered a second-generation H1-receptor antagonist antihistamine, being a major metabolyte of hydroxyzine - an oral medication used to relieve itching caused by allergies. Hydroxizine is also used to control nausea caused by various factors, including motion sickness. It is also useful in alleviating anxiety caused by alcohol withdrawal. A person who is allergic to hydroxizine should also experience some allergic reactions to cetirizine HCI.

For best results, Zyrtec should be taken once a day. Studies have shown that the effects of a single dose of Zyrtec could last up to 24 hours. Relief of allergic symptoms is experienced within 1 hour after ingestion of the tablet.

Even if you avoid contact with allergenic substances that are found outdoors, you may still encounter them indoors, in the form of dust, household mold and pet fur. This makes them even harder to escape, and may make you prone to contract allergies all year round! However, taking Zyrtec daily should be able to prevent the onset of a full-blown allergy attack.

Note that Zyrtec does not only alleviate the symptoms of nasal allergies. It also helps relieve itchy skin and hives, which may be symptoms of a skin allergy. Even if you are not sure what caused the hives or the itchiness, taking this medicine on a regular basis should prevent any more outbreaks.

A small dose of Zyrtec is safe for use even for children under the age of 12. It may be difficult to make kids take adult pills, even if they were broken up into smaller kid-sized portions, but not to worry: there is a tastier alternative. Zyrtec Syrup was specially formulated to have a delicious banana-grape flavor that kids are sure to like.

The amount of cetirizine HCI in Zyrtec Syrup has also been significantly reduced so that it can safely be ingested by children. However, the amount of medicine your child should receive also depends on his or her age and weight. Pay close attention to the directions indicated on the label.

This medicine is generally safe for adult use, but there are some things you must take into consideration before taking this drug. For example, this medicine may cause drowsiness, so it is important not to schedule your intake when you are about to drive or operate heavy machinery.

People who habitually experience colds along with allergy attacks could use a little extra protection. Zyrtec-D 12-Hour Extended Release Tablets combine the allergy-fighting properties of cetirizine HCI and the decongestant effects of pseudoephedrine. Side effects are rare, but they do occur, and the symptoms vary: you may experience dryness in your mouth, fatigue or insomnia.

It is important to note, however, that this medicine may cause complications if combined with other medications, such as MAO inhibitors. People with high blood pressure problems or heart disorders should avoid taking this drug as well. If you are taking any other medications, make sure to consult your doctor or pharmacist before taking Zyrtec-D. This medicine is not recommended for use by children younger than 12.