Sulphonamides act as

Options

A. hypnotics
B. antidepressants
C. antimicrobials
D. antiseptics

Answer

### Step-by-Step Solution

1. **Understanding Sulphonamides**:
- Sulphonamides, commonly known as sulfa drugs, are a class of medications that contain a sulfonamide group. They are primarily used to treat bacterial infections.

2. **Structure of Sulphonamides**:
- The general structure of sulphonamides includes a sulfonamide group (R-SO2-NR2) where R represents an alkyl or aryl group. This structure is crucial for their function as antibiotics.

3. **Mechanism of Action**:
- Sulphonamides work by inhibiting the synthesis of folic acid in bacteria, which is essential for their growth and reproduction. This makes them effective against a variety of bacterial infections.

4. **Classification of Action**:
- **Antimicrobials**: Sulphonamides are classified as antimicrobials because they target and kill or inhibit the growth of microorganisms, particularly bacteria.
- **Hypnotics**: They are not typically classified as hypnotics, which are drugs that induce sleep.
- **Antidepressants**: They do not act as antidepressants, which are medications used to treat depression by affecting neurotransmitters in the brain.
- **Antiseptics**: While they may have some antiseptic properties, their primary use is not as antiseptics for treating wounds.

5. **Applications of Sulphonamides**:
- Sulphonamides are used in the treatment of various bacterial infections, including urinary tract infections (UTIs), eye infections, and respiratory infections like bronchitis.

6. **Conclusion**:
- Based on their primary function, sulphonamides act predominantly as **antimicrobials**.