Antihistamines are medicines used to alleviate the effects of allergic reactions by blocking the action of histamine, a molecule involved in inflammation and allergic symptoms, such as itching, redness, or skin rashes. In dermatology, they are frequently prescribed to relieve symptoms of urticaria, atopic eczema, or insect bites. Antihistamines are available in oral, topical, or injectable forms.
The primary antihistamines used are H1 antihistamines for allergies and H2 antihistamines for gastric disorders, but there are also H3 and H4 antihistamines.
What are the most common antihistamines?
Loratadine, cetirizine, and fexofenadine are among the antihistamines most commonly used in the second generation.
Do antihistamines cause drowsiness?
The antihistamines of the first generation, such as diphenhydramine, can cause drowsiness, but this side effect is very rare with those of the second generation.
Can one obtain antihistamines without a prescription?
Some antihistamines are available over-the-counter, but it is advisable to seek advice from a doctor or pharmacist.
Can antihistamines be used during pregnancy?
This depends on the antihistamines, but some can be used by pregnant women. The key is to consult with a doctor beforehand.