Tigecycline is an antibiotic used to treat a number of bacterial infections. it is a first-in-class glycylcycline that is administered intravenously. it was developed in response to the growing rate of antibiotic resistance in bacteria such as staphylococcus aureus, acinetobacter baumannii, and e. coli. as a tetracycline derivative antibiotic, its structural modifications has expanded its therapeutic activity to include gram-positive and gram-negative organisms, including those of multi-drug resistance. it is approved to treat complicated skin and soft tissue infections (cssti), complicated intra-abdominal infections (ciai), and community-acquired bacterial pneumonia (cap) in individuals 18 years and older.