tigecycline

Tigecycline is a glycylcycline antibiotic derived from minocycline and belongs to the tetracycline class. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, blocking the entry of aminoacyl-tRNA to the ribosome and causing disruption of protein production. The drug is generally bacteriostatic and can overcome several common tetracycline resistance mechanisms.

The antimicrobial spectrum is broad, with activity against many Gram-positive organisms, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus, as well as many Gram-negative bacteria and anaerobes. Its activity against Pseudomonas aeruginosa and some other nonfermenters is limited or poor. Tigecycline is frequently discussed for use in complicated intra-abdominal infections and complicated skin and skin structure infections, and it has been studied for other indications in various regions. In the United States, it was initially approved for complicated intra-abdominal infections and complicated skin and soft-tissue infections, and safety concerns have influenced its recommended role in therapy.

Pharmacologically, tigecycline is administered intravenously due to very limited oral bioavailability. It achieves a large volume of distribution and high tissue concentrations, with a prolonged elimination half-life (roughly one to two days). It is primarily eliminated via biliary excretion, with minimal renal clearance; dose adjustments are not routinely required for renal impairment, though hepatic considerations can be relevant. The drug is associated with common adverse effects such as nausea, vomiting, and diarrhea, and has a boxed warning about an increased risk of all-cause mortality in some indications, leading to more cautious use. Tigecycline can cause teeth and bone effects and is generally avoided in pregnancy and in young children.