Common Drug Paired with Tigecycline
Tigecycline, a glycylcycline antibiotic for complicated infections like intra-abdominal and skin infections, is often paired with metronidazole. This combination targets mixed infections, with tigecycline covering gram-positive, gram-negative, and anaerobes, while metronidazole enhances anaerobic coverage, especially for Bacteroides fragilis.[1]
Why Metronidazole?
Clinical guidelines and studies recommend adding metronidazole to tigecycline for polymicrobial abdominal infections where anaerobes predominate. Tigecycline alone has limited activity against some strict anaerobes, so this pairing improves outcomes in conditions like perforated appendicitis or diverticulitis.[2][3]
Other Frequent Pairings
- Colistin or polymyxin B: Used with tigecycline for multidrug-resistant gram-negatives like Acinetobacter or carbapenem-resistant Enterobacteriaceae (CRE) in ventilator-associated pneumonia or bacteremia.[4]
- Meropenem or other beta-lactams: Combined for severe sepsis or when tigecycline's bacteriostatic nature needs a bactericidal boost.[5]
When Is Pairing Needed?
Pair tigecycline with another agent in polymicrobial or resistant cases; monotherapy suffices for some skin infections. Guidelines from IDSA advise against tigecycline monotherapy for certain hospital-acquired pneumonias due to higher mortality risks.[6]
Clinical Evidence and Risks
Trials like the ATTACK study showed tigecycline plus metronidazole noninferior to imipenem/cilastatin for intra-abdominal infections. Risks include tigecycline's nausea (common, managed with antiemetics) and potential for higher mortality in ventilated patients when used alone.[3][7]
Sources
[1] StatPearls: Tigecycline
[2] IDSA Guidelines: Complicated Intra-abdominal Infections
[3] NEJM: Tigecycline vs Imipenem/Cilastatin
[4] CID: Tigecycline for MDR Gram-Negatives
[5] CMI: Combination Therapy Review
[6] IDSA HAP/VAP Guidelines
[7] <a href="https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-warns-increased-risk-death-serious-tigecycline-tygacil-and-orders FDA Tigecycline Warning