Tygacil
Tygacil - General Information
Tygacil is an glycylcycline antibiotic developed and marketed by Wyeth under the brand name Tygacil. It was given a U.S. Food and Drug Administration (FDA) fast-track approval and was approved on June 17, 2005. It was developed in response to the growing prevalence of antibiotic resistance in bacteria such as Staphylococcus aureus.
Pharmacology of Tygacil
Tygacil is the first clinically-available drug in a new class of antibiotics called the glycylcyclines. Glycylcyclines are a new class of antibiotics derived from tetracycline. These tetracycline analogues are specifically designed to overcome two common mechanisms of tetracycline resistance, namely resistance mediated by acquired efflux pumps and/or ribosomal protection. Glycylcycline antibiotics have a similar mechanism of action as tetracycline antibiotics. Both classes of antibiotics bind to the 30S ribosomal subunit to prevent the amino-acyl tRNA from binding to the A site of the ribosome. However, the glycylcyclines appear to bind more effectively than the tetracyclines.
Tygacil for patients
Patients should be counseled that antibacterial drugs including TYGACIL should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When TYGACIL is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by TYGACIL or other antibacterial drugs in the future.
Tygacil Interactions
Prothrombin time or other suitable anticoagulation test should be monitored if tigecycline is administered with warfarin.
Concurrent use of antibacterial drugs with oral contraceptives may render oral contraceptives less effective.
Drug/Laboratory Test Interactions
There are no reported drug-laboratory test interactions.
Tygacil Contraindications
TYGACIL is contraindicated for use in patients who have known hypersensitivity to tigecycline or tetracycline antibiotics.
Additional information about Tygacil
Tygacil Indication: For the treatment of infections caused by susceptible strains of the designated microorganisms in the following conditions: Complicated skin and skin structure infections caused by Escherichia coli, Enterococcus faecalis (vancomycin-susceptible isolates only), Staphylococcus aureus (methicillin-susceptible and -resistant isolates), Streptococcus agalactiae, Streptococcus anginosus grp. (includes S. anginosus, S. intermedius, and S. constellatus), Streptococcus pyogenes and Bacteroides fragilis. Complicated intra-abdominal infections caused by Citrobacter freundii, Enterobacter cloacae, Escherichia coli, Klebsiella oxytoca, Klebsiella pneumoniae, Enterococcus faecalis (vancomycin-susceptible isolates only), Staphylococcus aureus (methicillin-susceptible isolates only), Streptococcus anginosus grp. (includes S. anginosus, S. intermedius, and S. constellatus), Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides uniformis, Bacteroides vulgatus, Clostridium perfringens, and Peptostreptococcus micros.
Mechanism Of Action: Tygacil, a glycylcycline, inhibits protein translation in bacteria by binding to the 30S ribosomal subunit and blocking entry of amino-acyl tRNA molecules into the A site of the ribosome. This prevents incorporation of amino acid residues into elongating peptide chains. Tygacil carries a glycylamido moiety attached to the 9-position of minocycline. The substitution pattern is not present in any naturally occurring or semisynthetic tetracycline and imparts certain microbiologic properties to tigecycline. Tygacil is not affected by the two major tetracycline resistance mechanisms, ribosomal protection and efflux. Accordingly, tigecycline has demonstrated in vitro and in vivo activity against a broad spectrum of bacterial pathogens. There has been no cross resistance observed between tigecycline and other antibiotics. Tygacil is not affected by resistance mechanisms such as beta-lactamases (including extended spectrum beta-lactamases), target site modifications, macrolide efflux pumps or enzyme target changes (e.g. gyrase/topoisomerase). In vitro studies have not demonstrated antagonism between tigecycline and other commonly used antibacterial drugs. In general, tigecycline is considered bacteriostatic.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Tigecycline
Synonyms: GAR-936; WAY-GAR-936
Drug Category: Antibacterial Agents
Drug Type: Small Molecule; Approved; Investigational
Other Brand Names containing Tigecycline: Tygacil;
Absorption: Not Available
Toxicity (Overdose): Since glycylcyclines are similar to tetracyclines, they share many of the same side effects and contraindications as tetracyclines. These side effects may include nausea/vomiting, headache, photosensitivity, discoloration of growing teeth, and fetal damage.
Protein Binding: 71% to 89%
Biotransformation: Tigecycline is not extensively metabolized. In vitro studies with tigecycline using human liver microsomes, liver slices, and hepatocytes led to the formation of only trace amounts of metabolites. A glucuronide, an N-acetyl metabolite, and a tigecycline epimer (each at no more than 10% of the administered dose) are the primary metabolites.
Half Life: 27-43 hours
Dosage Forms of Tygacil: Powder, for solution Intravenous
Chemical IUPAC Name: N-[(5aR,6aS,7S,9Z,10aS)-9-(amino-hydroxymethylidene)-4,7-bis(dimethylamino)-1,10a,12-trihydroxy-8,10,11-trioxo-5a,6,6a,7-tetrahydro-5H-tetracen-2-yl]-2-(tert-butylamino)acetamide
Chemical Formula: C29H39N5O8
Tigecycline on Wikipedia: https://en.wikipedia.org/wiki/Tigecycline
Organisms Affected: Enteric bacteria and other eubacteria