Introduction
Antihistamines are a type of medication that can be used to treat allergic reactions and symptoms due to allergies. Allergic reactions are caused by the body’s immune system overreacting to substances known as allergens. Antihistamines work by blocking the action of a chemical called histamine, which is responsible for many of the symptoms of an allergic reaction. In this article, we will discuss the types of antihistamines, how they work, and their potential side effects.
Types of Antihistamines
Antihistamines can be divided into two main types: first-generation and second-generation. First-generation antihistamines are more commonly known as sedating antihistamines, as they tend to cause drowsiness and other side effects. These are usually taken when needed, and commonly include diphenhydramine, hydroxyzine, and promethazine. Second-generation antihistamines are less likely to cause drowsiness and are usually taken regularly to prevent symptoms. These include loratadine, cetirizine, and fexofenadine.
How Antihistamines Work
Antihistamines work by blocking the action of histamine, a chemical that is released during an allergic reaction. Histamine binds to receptors on the surface of cells, causing them to become inflamed and triggering the symptoms of an allergic reaction, such as itching, sneezing, and a runny nose. Antihistamines block these receptors, preventing the release of histamine and reducing the severity of the allergic reaction.
Side Effects of Antihistamines
Though antihistamines are generally safe and effective, they can cause side effects in some people. Common side effects of first-generation antihistamines include drowsiness, dry mouth, and blurred vision. Second-generation antihistamines are less likely to cause drowsiness, but can still cause other side effects such as nausea, vomiting, and dizziness. It is important to speak to a doctor or pharmacist before taking any medication, as some antihistamines may interact with other medications or cause serious side effects.
Conclusion
Antihistamines are a type of medication that can be used to treat allergic reactions and symptoms due to allergies. They work by blocking the action of histamine, a chemical released during an allergic reaction. Antihistamines can be divided into two main types: first-generation and second-generation. First-generation antihistamines are more likely to cause drowsiness, while second-generation antihistamines are less likely to do so. Though antihistamines are generally safe and effective, they can cause side effects in some people and should only be taken after consulting a doctor or pharmacist.
References
American Academy of Allergy, Asthma & Immunology (AAAAI). (2020). Antihistamines. Retrieved from https://www.aaaai.org/conditions-and-treatments/allergies/antihistamines
Mayo Clinic. (2020). Allergies. Retrieved from https://www.mayoclinic.org/diseases-conditions/allergies/symptoms-causes/syc-20351497
National Institute of Allergy and Infectious Diseases (NIAID). (2020). Allergic Reactions. Retrieved from https://www.niaid.nih.gov/diseases-conditions/allergic-reactions