Which general category of drugs is the most selectively toxic to microorganisms?

• A. Antiprotozoal drugs
• B. Antifungal drugs
• C. Antiviral drugs
• D. Antibacterial drugs

Answer: (D)

Verified step by step guidance

1. Understand the concept of selective toxicity, which refers to a drug's ability to target microorganisms without harming the host's cells.
2. Recognize that selective toxicity depends on differences between microbial cells and human cells, such as cell wall presence, metabolic pathways, or ribosomal structure.
3. Evaluate the general categories of antimicrobial drugs: antiprotozoal, antifungal, antiviral, and antibacterial drugs, considering how each targets unique features of microorganisms.
4. Note that antibacterial drugs exploit many unique bacterial features (like peptidoglycan cell walls and 70S ribosomes) that are absent in human cells, allowing for high selective toxicity.
5. Conclude that among the options, antibacterial drugs are the most selectively toxic because they target bacterial-specific structures and functions more effectively than the other categories.