Table of Contents
What is Antihistamine?
Antihistamine – Drugs Classification: An antihistamine is a drug that blocks the action of histamine, a chemical released in the body during an allergic reaction. Histamine is responsible for many of the symptoms of allergy, such as a runny nose, sneezing, and itchy eyes. Antihistamines work by preventing histamine from binding to its receptors on cells in the body.
The Action of Antihistamines on the Human Body, How do they Suppress Antihistamines?
- Antihistamines are a class of medications that are used to treat a variety of conditions, including allergies and asthma. They work by blocking the effects of histamine, which is a chemical that is released by the body in response to an allergic reaction. By blocking histamine, antihistamines can help to reduce the symptoms of an allergic reaction.
- Antihistamines can be taken orally or they can be administered by injection or nasal spray. They are available over the counter and by prescription.
- Antihistamines work by blocking the effects of histamine, which is a chemical that is released by the body in response to an allergic reaction. By blocking histamine, antihistamines can help to reduce the symptoms of an allergic reaction.
- Antihistamines can be taken orally or they can be administered by injection or nasal spray. They are available over the counter and by prescription.
Antihistamine Drugs Classification
- Antihistamine drugs are classified into two groups: first-generation and second-generation drugs.
- First-generation antihistamines are older drugs that are available over-the-counter and include diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), and brompheniramine (Dimetapp). These drugs are effective at relieving sneezing, runny nose, and itching, but they can also cause drowsiness.
- Second-generation antihistamines are newer drugs that are available by prescription only and include cetirizine (Zyrtec), fexofenadine (Allegra), and loratadine (Claritin). These drugs are also effective at relieving sneezing, runny nose, and itching, but they are less likely to cause drowsiness.
Example of Drugs and Antihistamine Uses According to Antihistamine Classification
- There are many different types of antihistamines, classified by their chemical structure.
- The most common antihistamines are the first-generation drugs, which include diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton).
- These drugs are effective in treating allergic rhinitis, urticaria, and other types of histamine-mediated conditions.
- They work by blocking histamine receptors, which reduces the symptoms of allergy and inflammation.
- Second-generation antihistamines, such as cetirizine (Zyrtec) and loratadine (Claritin), are also effective in treating allergies, but they are less likely to cause sedation.
- Third-generation antihistamines, such as fexofenadine (Allegra), are also effective in treating allergies, but they are less likely to cause sedation or interact with other medications.
Antihistamine Side-Effects
Some people experience side-effects when taking antihistamines. These side-effects may include:
- Drowsiness
- Dizziness
- Headache
- Nausea
- Vomiting
- Constipation
- Diarrhea
- Rash
- Hives
It is important to speak with your doctor if you are experiencing any side-effects while taking antihistamines.
