Antihistaminic

Antihistaminic

Antihistaminic (pronunciation: an·ti·his·ta·min·ic /ˌæntiˌhɪstəˈmɪnɪk/) refers to a type of drug that inhibits the physiological effects of histamine.

Etymology

The term "antihistaminic" is derived from the prefix "anti-" meaning against, and "histamine," a compound that is involved in local immune responses.

Function

Antihistaminics are primarily used to treat allergies. They work by blocking the action of histamine, a substance in the body that causes allergic symptoms. When an individual is exposed to an allergen, the body produces histamine, which binds to certain sites (receptors) in the body and causes symptoms such as itching, sneezing, and a runny nose. Antihistaminics prevent histamine from binding to these receptors, thereby reducing or eliminating the symptoms.

Types

There are two main types of antihistaminics: H1 antihistamines and H2 antihistamines.

• H1 antihistamines are used to treat symptoms such as itching, sneezing, and a runny nose. They are commonly used to treat conditions such as hay fever and hives. Examples of H1 antihistamines include diphenhydramine (Benadryl), loratadine (Claritin), and cetirizine (Zyrtec).

• H2 antihistamines are used to reduce the production of stomach acid and are commonly used to treat conditions such as peptic ulcers and gastroesophageal reflux disease (GERD). Examples of H2 antihistamines include cimetidine (Tagamet), ranitidine (Zantac), and famotidine (Pepcid).

Side Effects

Like all medications, antihistaminics can cause side effects. Common side effects of antihistaminics include drowsiness, dry mouth, dizziness, and nausea. In rare cases, they can cause more serious side effects such as confusion, difficulty urinating, and blurred vision.

Related Terms

• Histamine
• Allergy
• H1 antihistamines
• H2 antihistamines
• Diphenhydramine
• Loratadine
• Cetirizine
• Cimetidine
• Ranitidine
• Famotidine

External links

• Medical encyclopedia article on Antihistaminic
• Wikipedia's article - Antihistaminic

This WikiMD dictionary article is a stub. You can help make it a full article.

---

Languages: - East Asian 中文, 日本, 한국어, South Asian हिन्दी, Urdu, বাংলা, తెలుగు, தமிழ், ಕನ್ನಡ,
Southeast Asian Indonesian, Vietnamese, Thai, မြန်မာဘာသာ, European español, Deutsch, français, русский, português do Brasil, Italian, polski