Tigecycline's Main Targets
Tigecycline, a glycylcycline antibiotic, works against multidrug-resistant Gram-positive, Gram-negative, and anaerobic bacteria. It binds to the 30S ribosomal subunit, inhibiting protein synthesis, and evades common resistance mechanisms like efflux pumps.[1]
Gram-Positive Bacteria It Covers
Effective against:
- Methicillin-resistant Staphylococcus aureus (MRSA)
- Vancomycin-resistant Enterococcus (VRE), including E. faecium
- Streptococcus pneumoniae, including penicillin-resistant strains
- Other staphylococci and streptococci
Gram-Negative Bacteria It Covers
Covers many resistant strains:
- Acinetobacter baumannii, including carbapenem-resistant
- Enterobacterales like Escherichia coli, Klebsiella pneumoniae (extended-spectrum beta-lactamase producers), and Enterobacter spp.
- Pseudomonas aeruginosa (limited activity; not first-line)
Anaerobes and Atypicals
Strong against anaerobes such as Bacteroides fragilis, Clostridium spp., and Peptostreptococcus. Also hits atypicals like Legionella pneumophila and some Mycoplasma/Chlamydia.
Key Limitations and Resistance
Poor activity against Pseudomonas aeruginosa, Proteus spp., and Providencia spp. due to efflux. Not for bloodstream infections (FDA black box warning for increased mortality). Resistance emerges via ribosomal mutations or efflux overexpression.[1][2]
Clinical Uses by Infection Type
Approved for complicated skin/skin structure infections, intra-abdominal infections, and community-acquired pneumonia caused by susceptible pathogens listed above. Often reserved for resistant cases where other options fail.[3]
[1]: https://www.drugpatentwatch.com/p/tradesparql/tigecycline
[2]: FDA Label - Tygacil (tigecycline)
[3]: Clinical Infectious Diseases Society of America (IDSA) guidelines on resistant infections