title: Tigecycline: a glycylcycline antimicrobial agent.
abstract: BACKGROUND
  Tigecycline, the first glycylcycline to be approved by the US Food and Drug Administration, is a structural analogue of minocycline that was designed to avoid tetracycline resistance mediated by ribosomal protection and drug efflux. It is indicated for the treatment of complicated skin and skin-structure infections and complicated intra-abdominal infections and is available for intravenous administration only.
  
  
  OBJECTIVE
  This article summarizes the in vitro and in vivo activities and pharmacologic and pharmacokinetic properties of tigecycline, and reviews its clinical efficacy and tolerability profile.
  
  
  METHODS
  Relevant information was identified through a search of MEDLINE (1966-April 2006), Iowa Drug Information Service (1966-April 2006), and International Pharmaceutical Abstracts (1970-April 2006) using the terms tigecycline, GAR-936, and glycylcycline. Also consulted were abstracts and posters from meetings of the Infectious Diseases Society of America and the Interscience Conference on Antimicrobial Agents and Chemotherapy (1999-2006) and documents provided for formulary consideration by the US manufacturer of tigecycline.
  
  
  RESULTS
  Like the tetracyclines, tigecycline binds to the 30S subunit of bacterial ribosomes and inhibits protein synthesis by preventing the incorporation of amino acid residues into elongating peptide chains. In vitro, tigecycline exhibits activity against a wide range of clinically significant gram-positive and gram-negative bacteria, including multidrug-resistant strains (eg, oxacillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Enterobacteriaceae), and anaerobes (eg, Bacteroides spp). In pharmacokinetic studies in human adults, tigecycline had a large Vd (7-9 L/kg), was moderately bound to plasma protein (71%-89%), had an elimination t(1/2) of 42.4 hours, and was eliminated primarily by biliary/fecal (59%) and renal (33%) excretion. Dose adjustment did not appear to be necessary based on age, sex, renal function, or mild to moderate hepatic impairment (Child-Pugh class A-B). In patients with severe hepatic impairment (Child-Pugh class C), the maintenance dose should be reduced by 50%. In 4 Phase III clinical trials in patients with complicated skin and skin-structure infections and complicated intra-abdominal infections, tigecycline was reported to be noninferior to its comparators (vancomycin + aztreonam in 2 studies and imipenem/cilastatin in 2 studies), with clinical cure rates among clinically evaluable patients of >80% (P < 0.001 for noninferiority). The most frequently reported (> or =5 %) adverse events with tigecycline were nausea (28.5%), vomiting (19.4%), diarrhea (11.6%), local IV-site reaction (8.2%), infection (6.7%), fever (6.3%), abdominal pain (6.0%), and headache (5.6%). The recommended dosage of tigecycline is 100 mg IV given as a loading dose, followed by 50 mg IV g12h for 5 to 14 days.
  
  
  CONCLUSIONS
  In clinical trials, tigecycline was effective for the treatment of complicated skin and skin-structure infections and complicated intra-abdominal infections. With the exception of gastrointestinal adverse events, tigecycline was generally well tolerated. With a broad spectrum of activity that includes multidrug-resistant gram-positive and gram-negative pathogens, tigecycline may be useful in the treatment of conditions caused by these pathogens.
authors.affiliation: Pharmacy Department, Long Island Jewish Medical Center, New Hyde Park, New York, USA.
authors.forename: Thien-Ly
authors.initials: TL
authors.lastname: Doan
authors.affiliation: Medicine/Surgery Patient Care Center, James Peters VA Medical Center, Bronx, New York, USA. Electronic address: horatio.fung@va.gov.
authors.forename: Horatio B
authors.initials: HB
authors.lastname: Fung
authors.affiliation: Pharmacy Service, James Peters VA Medical Center, Bronx, New York, USA.
authors.forename: Dhara
authors.initials: D
authors.lastname: Mehta
authors.affiliation: Infections Diseases Section, James Peters VA Medical Center, Bronx, New York, USA.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Riska
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D004347:Drug Interactions; D024901:Drug Resistance, Multiple, Bacterial; D017850:Economics, Pharmaceutical; D006801:Humans; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D017192:Skin Diseases, Bacterial / Q000188:drug therapy; D018461:Soft Tissue Infections / Q000188:drug therapy; D000078304:Tigecycline
chemical_list: D000900:Anti-Bacterial Agents; D000078304:Tigecycline; D008911:Minocycline