What Infections Does Tigecycline Target?
Tigecycline, a glycylcycline antibiotic, primarily treats complicated skin and skin structure infections (cSSSI), complicated intra-abdominal infections (cIAI), and community-acquired bacterial pneumonia (CABP) caused by susceptible bacteria. It covers multidrug-resistant strains like MRSA, vancomycin-resistant Enterococcus faecium (VRE), and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae.[1]
Key Pathogens It Fights
Effective against:
- Aerobes: Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, Enterobacter spp., Staphylococcus aureus (including MRSA), Streptococcus pneumoniae, Haemophilus influenzae.
- Anaerobes: Bacteroides fragilis, Clostridium spp., Peptostreptococcus spp.
It has broad-spectrum activity but limited efficacy against Pseudomonas aeruginosa and Proteus spp.[1][2]
FDA-Approved Uses
Approved for adults with:
- cSSSI from S. aureus, Streptococcus pyogenes, E. coli, or Bacteroides fragilis.
- cIAI from Citrobacter freundii, E. coli, K. oxytoca, K. pneumoniae, or Bacteroides spp.
- CABP from S. pneumoniae, H. influenzae, or S. aureus.[1]
How Tigecycline Works Against Bacteria
It binds to the 30S ribosomal subunit, inhibiting protein synthesis. This overcomes common resistance mechanisms like efflux pumps in tetracyclines, making it useful for resistant Gram-positive, Gram-negative, and anaerobic infections.[2]
Common Off-Label or Investigational Uses
Sometimes used for hospital-acquired pneumonia, diabetic foot infections, or infections from multidrug-resistant Acinetobacter or Klebsiella, though not FDA-approved for these. Evidence from trials shows variable success.[2]
Limitations and When It Fails
Higher mortality risk in some ventilator-associated pneumonia studies led to warnings. Avoid in bloodstream infections due to low serum levels. Not for urinary tract infections (poor concentrations) or children under 8.[1][2]
[1]: FDA Label for Tygacil (tigecycline)
[2]: Drugs.com - Tigecycline