Antibiotics effective for anaerobic infections

Common IV Antibiotics for Anaerobic Infections

1. Metronidazole
   Use: Intra-abdominal infections, Clostridioides difficile colitis, gynecological infections.
   Details: The gold standard for anaerobes, especially below the diaphragm.

2. Piperacillin-Tazobactam (Zosyn)
   Use: Intra-abdominal infections, polymicrobial infections.
   Details: Broad-spectrum coverage, including anaerobes, often used in hospital settings for serious infections.

3. Ertapenem
   Use: Intra-abdominal infections, skin and soft tissue infections.
   Details: Carbapenem with broad anaerobic coverage, excluding Pseudomonas, often used for mixed infections.

4. Meropenem / Imipenem
   Use: Severe polymicrobial infections, intra-abdominal infections.
   Details: Carbapenems offering excellent anaerobic coverage, also active against resistant organisms.

5. Clindamycin
   Use: Aspiration pneumonia, dental infections, and skin/soft tissue infections.
   Details: Effective for anaerobic infections, especially above the diaphragm, but carries a higher risk of C. difficileinfection.

6. Cefoxitin / Cefotetan
   Used and misused for: Intra-abdominal infections, gynecological infections.
   Details: Second-generation cephalosporins with anaerobic activity, often used for surgical prophylaxis. Not useful much anymore clinically due to increasing anaerobic resistance.

7. Ampicillin-Sulbactam (Unasyn)

Use: Polymicrobial infections, including intra-abdominal and gynecological infections.       Details: Broad anaerobic and gram-positive coverage, but has limitations for gram-negative coverage, and not preferred for gastrointestinal infections in certain cases.

 

Common Oral Antibiotics for Anaerobic Infections

1. Metronidazole
   Use: Intra-abdominal infections, bacterial vaginosis, C. difficile colitis.
   Details: A staple for anaerobic infections, particularly effective below the diaphragm.

2. Clindamycin
   Use: Dental infections, aspiration pneumonia, skin/soft tissue infections.
   Details: Covers anaerobes, especially for infections above the diaphragm, but carries a high risk of C. difficile.

3. Amoxicillin-Clavulanate (Augmentin)
   Use: Polymicrobial infections, aspiration pneumonia.
   Details: Broad anaerobic coverage, particularly useful in mixed infections.

4. Moxifloxacin
   Use: Respiratory, intra-abdominal, and skin infections.
   Details: Offers anaerobic coverage but generally used for mixed infections; not typically first-line for anaerobes alone.

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Conclusion

For IV treatment of anaerobic infections, Metronidazole, Piperacillin-Tazobactam, and carbapenems are commonly used, providing strong anaerobic coverage. Oral options include Metronidazole and Clindamycin, with Augmentin and Moxifloxacin often used in polymicrobial or mixed infections.