Tigecycline: a new glycylcycline antimicrobial.

Tigecycline is a new glycyclcycline antimicrobial recently approved for use in the USA, Europe and elsewhere. While related to the tetracyclines, tigecycline overcomes many of the mechanisms responsible for resistance to this class. It demonstrates favourable in vitro potency against a variety of aerobic and anaerobic Gram-positive and Gram-negative pathogens, including those frequently demonstrating resistance to multiple classes of antimicrobials. This includes methicillin-resistant Staphylococcus aureus, penicillin-resistant S. pneumoniae, vancomycin-resistant enterococci, Acinetobacter baumannii, beta-lactamase producing strains of Haemophilis influenzae and Moraxella catarrhalis, and extended-spectrum beta-lactamase producing strains of Escherichia coli and Klebsiella pneumoniae. In contrast, minimum inhibitory concentrations for Pseudomonas and Proteus spp. are markedly elevated. Tigecycline is administered parenterally twice daily. Randomised, controlled trials have demonstrated that tigecycline is non-inferior to the comparators for the treatment of complicated skin and skin structure infections, as well as complicated intra-abdominal infections. The most frequent and problematic side effect associated with its administration to date has been nausea and/or vomiting.