Final answer:
The non-sedating 2nd generation antihistamines listed in the student's question are Desloratadine (A) and Azelastine (C), which are useful in treating allergic reactions without causing significant drowsiness.
Step-by-step explanation:
The student's question asks which of the provided options are considered 2nd generation antihistamines that are non-sedating. Among the options given:
- Desloratadine: A non-sedating, second-generation antihistamine.
- Hydroxyzine: A first-generation antihistamine, known for its sedative properties.
- Azelastine: Another non-sedating, second-generation antihistamine.
- Promethazine: A first-generation antihistamine that can cause sedation.
Therefore, the correct answers are Desloratadine (A) and Azelastine (C). These antihistamines function by binding to the histamine H₁ receptors in the body, and they are typically used to treat allergic reactions without causing drowsiness.