Which of the following is employed as antihistamine .

Options

A. Omeperazole
B. Chloramphenicol
C. Diphenylhydramine
D. Norethindrone

Answer

To determine which of the given options is employed as an antihistamine, we can analyze each option based on their definitions and uses:

1. **Omeprazole**:
- Omeprazole is classified as an antacid. It is used to reduce stomach acidity and treat conditions like gastroesophageal reflux disease (GERD). It does not have antihistamine properties.

2. **Chloramphenicol**:
- Chloramphenicol is an antibiotic that is effective against a wide range of bacterial infections. It is not used as an antihistamine.

3. **Diphenylhydramine**:
- Diphenylhydramine is specifically known as an antihistamine. It is used to relieve symptoms associated with allergies, such as rashes, itching, watery eyes, and sneezing. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

4. **Norethindrone**:
- Norethindrone is an anti-fertility drug, commonly used in birth control. It does not serve as an antihistamine.

Based on the analysis above, the correct answer to the question is:

**Diphenylhydramine** is employed as an antihistamine.