Antimicrobials Practice Test 2026 - Free Practice Questions and Study Guide on Antimicrobials

Metronidazole is primarily effective against anaerobic bacteria and certain protozoa, making it particularly useful for gastrointestinal (GI) infections. Conditions such as Clostridium difficile associated diarrhea, infections caused by Bacteroides and other anaerobes, and protozoal infections such as giardiasis and amoebiasis are commonly treated with metronidazole.

The effectiveness of metronidazole in treating GI infections stems from its ability to penetrate tissues and its action against organisms that other antimicrobials may not effectively target. This makes it the drug of choice in specific scenarios involving the gastrointestinal tract, where anaerobes are frequently involved.

In contrast, while skin infections, urinary tract infections, and upper respiratory infections can arise from various pathogens, metronidazole is not typically the first-line treatment for these conditions due to the predominance of aerobic bacteria and differing pathogen profiles that are commonly present. As a result, metronidazole is not indicated for the other options listed, as those infections generally require different classes of antibiotics that target the most prevalent bacteria in those areas.