[Allergy DIY in Korea] Allergy medications you can buy without prescriptions in pharmacy.
Yes, we do have Zytec. And what else?
Allergies, or allergic diseases are hypersensitive reaction against external attack(not normally considered as an attack). Once you experienced allergic response, your body becomes more vulnerable to allergens. This is because of increased number of IgE (immunoglobulin E antibodies) in your body. (just like me..)
There are several diseases that are caused by allergy reaction, which includes allergic rhinitis, bronchial asthma, atopic dermatitis, drug allergy, etc. Generally, people with allergic rhinitis, conjunctivitis, hives visit pharmacy the most, and most of them seek Zyrtec. Yes, we do have Zyrtec. And what else do we have?
Allergy medications
There are several choices:
1) Corticosteroids
2) Bronthodilator
3) Leukotriene receptor antagonist
4) Antihistamine
Here, I will only deal with 4) anti-histamine, because the others are mostly Rx only medicines in Korea.
4) Antihistamine
There are several subclassified histamine receptors in the body which includes H1, H2. H1-antihistamine binds to H1 receptor in mast cells, smooth muscle, and endothelium in the body as well as in the tuberomammillary nucleus in the brain. H2-antihistamines binds to H2 receptors in the parietal cells of the gastric mucosa. Therefore, H1-antihistamies are used as allergy medication, and H2-antihistamines are used for peptic ulcers. H1-antihistamines can treat runny nose, sneezing, itching, but they are not effective for stuffed nose, asthma.
Over-the-counter antihistamine medication list in Korea.
Cetirizine: Zytec, Allertec, etc
Loratadine: Claritin, Alavert, Floradine, etc
Above 2nd generation antihistamines are generally used in Korean pharmacy.
Then what about 1st generations? They are used as OTC sleeping-aid preparations also in Korea. This is due to their ability to cross the blood-brain barrier which finally cause sedation.
What is the difference between Cetirizine and Loratadine?
1) How sleepy?
According to product information Cetirizine causes 9.63% (placebo 5%), Loratadine causes 4% (placebo 3%) of somnolence. Because of this difference, Loratadine products can be marketed as "less sleepy" antihistamine in Korea.
2) Half-life
Half-life of cetirizine is 7.8hrs and Loratadine is 12-15hrs. There is a difference of twice as much, but both are recommended to be taken 1 tablet/d.
3) Indications and usage
Cetirizine: allergic rhinitis, conjunctivitis, urticaria, dermatitis
Loratadine: allergic rhinitis, conjunctivitis, urticatria
About 3rd generation antihistamine in Korea?
Fexofenadine (Allegra) is also categorized as OTC in Korea, but not widely handled.
Levocetirizine (Xyzal) is Rx only medication in Korea.
What about antihistamines for external use?
There are several OTC antihistamine eye drops, nasal sprays available.
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