Tigecycline is the first commercially available member of the glycylcyclines, a new class of
antimicrobial agents. The glycylcyclines are derivatives of the
tetracycline antibiotics, with structural modifications that allow for potent gram-positive, gram-negative, and anaerobic activity, including certain multidrug-resistant strains. The enhanced activity can be attributed to stronger binding affinity and enhanced protection against several mechanisms of resistance that affect other
antibiotic classes such as
tetracyclines.
Tigecycline exhibits generally bacteriostatic action by reversibly binding to the 30S ribosomal subunit and inhibiting protein translation. In vitro activity has been demonstrated against multidrug-resistant gram-positive pathogens including methicillin-resistant and
glycopeptide-intermediate and -resistant Staphylococcus aureus, as well as vancomycin-resistant enterococci. Multidrug-resistant gram-negative pathogens, such as Acinetobacter baumannii and extended-spectrum
beta-lactamase-producing Klebsiella pneumoniae and Escherichia coli, are typically highly susceptible to
tigecycline. The
drug also has displayed significant activity against many clinically important anaerobic organisms. This agent demonstrates a predictable pharmacokinetic profile and minimal drug interactions, and is generally well tolerated, with
nausea being the most common adverse event. It was approved in June 2005 for the treatment of complicated skin and skin structure
infections (SSSIs) and complicated
intraabdominal infections. Currently, a limited number of broad-spectrum antimicrobials are available to combat multidrug-resistant organisms. The addition of new agents is essential to limiting the spread of these pathogens and improving outcomes in patients with these types of
infections.
Tigecycline has demonstrated promising results in initial in vitro and clinical studies for SSSIs and complicated
intraabdominal infections; however, further clinical experience will clarify its role as a broad-spectrum agent.