Antihistamines are a type of medication commonly used to treat allergic reactions and their associated symptoms. There are different types of antihistamines that act in various ways in the body to block the action of histamine, a chemical substance that triggers allergy symptoms. In this article, we will focus on the 4 main types of antihistamines, their specific characteristics and functions.
1. First Generation Antihistamines
First generation antihistamines are the oldest and most commonly used antihistamines. They work mainly by blocking histamine receptors in the brain, which gives them sedative and sleep-reducing properties. These antihistamines are effective in relieving symptoms such as sneezing, itchy, and watery eyes, but they can cause drowsiness and affect motor coordination.
Some examples of first-generation antihistamines include diphenhydramine, chlorpheniramine, and hydroxyzine. These medications are usually used to treat allergies, insect bites, hives, and skin reactions.
Functions of First Generation Antihistamines:
- Relief of allergic symptoms such as itching, sneezing and watery eyes.
- Sleep induction in people with difficulty falling asleep due to allergies.
- Treatment of skin reactions and hives.
2. Second Generation Antihistamines
Second generation antihistamines are a newer version of these medications and are designed to provide relief from allergic symptoms without causing as much drowsiness as the first generation. They act more specifically on peripheral histamine receptors, reducing sedative effects.
These antihistamines are a preferred choice for those seeking allergy relief without feeling drowsy or disoriented. Some examples of second generation antihistamines include loratadine, cetirizine and fexofenadine.
Functions of Second Generation Antihistamines:
- Relief of allergic symptoms such as sneezing, nasal congestion and red eyes.
- Less likely to cause drowsiness compared to first generation antihistamines.
- Safe use at work and during activities that require concentration.
3. Selective H1 Antihistamines
Selective H1 antihistamines are a subclass of second-generation antihistamines that specifically target H1 histamine receptors. These medications are highly selective in their action and are less likely to cause side effects such as sedation than first-generation antihistamines.
Selective H1 antihistamines are effective in treating symptoms such as itching, runny nose, and redness of the skin caused by allergic reactions. Common examples of selective H1 antihistamines include desloratadine, levocetirizine, and ebastine.
Functions of Selective H1 Antihistamines:
- Relief of allergic symptoms such as itching, redness, and discharge nasal.
- Lower risk of causing drowsiness compared to first generation antihistamines.
- Selective action on histamine H1 receptors.
4. Third Generation Antihistamines
Third generation antihistamines are the latest evolution in the treatment of allergies and are designed to be highly selective in their action on histamine receptors. These medications seek to provide effective relief of allergic symptoms with a minimum of side effects, including drowsiness.
Third-generation antihistamines are also expected to have a longer duration of action, meaning that They can be administered less frequently throughout the day. Examples of third generation antihistamines include rupatadine and bilastine.
Functions of Third Generation Antihistamines:
- Effective relief of allergic symptoms such as itching, sneezing and redness of the skin.
- Minimal side effects, such as drowsiness or sedation.
- Long duration of action that allows fewer daily doses.
In conclusion , antihistamines are an important part of pharmacotherapy for the treatment of allergies and their symptoms. With the variety of options available, it is possible to find the right antihistamine that provides effective relief from allergic symptoms without causing unwanted side effects. It is recommended to consult a health professional to determine the most appropriate antihistamine based on individual needs and each person's tolerance to these medications.