Which drug class is specifically indicated for life-threatening infections such as MRSA?

Vancomycin is a glycopeptide antibiotic that is specifically indicated for treating serious infections caused by Gram-positive bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA). MRSA is known for its resistance to multiple antibiotics, making it a significant concern in clinical settings. Vancomycin works by inhibiting bacterial cell wall synthesis, which is crucial for the growth and survival of bacteria.

This antibiotic is often reserved for severe infections where other antibiotics may not be effective due to resistance issues, hence its classification as a critical treatment option for life-threatening infections like those caused by MRSA. This makes it the appropriate choice among the options listed.

The other drug classes mentioned do not specifically target MRSA or are intended for different types of infections. Aminoglycosides, while effective against certain bacterial infections, are not typically the first line of defense against MRSA. Metronidazole is primarily used to treat anaerobic infections and certain protozoal infections, and antivirals are geared towards viral infections, making them unsuitable in the context of bacterial strains like MRSA.