Tigecycline is an antibiotic that is semisynthetic. It is used for complicated infections and infections with multidrug-resistant problem strains.
What is tigecycline?
Tigecycline is an antibiotic that is semisynthetically produced. The drug tigecycline belongs to the tetracycline antibiotics and antibiotic drugs from the glycylcycline class of drugs. Tigecycline is a derivative of tetracyclines. Because the drug is effective against many different pathogens, it is used as a broad-spectrum antibiotic. Broad-spectrum antibiotics cover many bacteria from the gram-negative and gram-positive range. They are also effective against chlamydiae, rickettsiae, spirochetes, or protozoa. Tigecycline is also effective against anaerobes such as clostridia. Infections caused by Escherichia coli or Acinetobacter baumannii can also be treated with tigecycline. Currently, tigecycline is also effective against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VCE), and ESBL-forming pathogens. As tigecycline has to be used more frequently due to increasing resistance, the widespread use of the antibiotic is expected to lead to further resistance in the future.
Pharmacologic action
Tigecycline acts like most tetracyclines. The drug inhibits protein biosynthesis at the ribosomes of pathogens. As a result, aminoacyl-tRNA can no longer attach to the 30S subunits of the ribosomes, making it impossible for the bacteria to multiply. Unlike other tetracyclines, tigecycline can circumvent two resistance mechanisms. Many resistant bacteria have so-called efflux pumps. These channel the antibiotic out of the bacterial cell through transport proteins. Tigecycline can bypass this protective mechanism. It also has a fivefold higher binding affinity to ribosomes, rendering various protective proteins of the bacteria ineffective.
Medical application and use
Tigecycline is a reserve antibiotic. Reserve antibiotics are special antibiotics used exclusively to treat infections with resistant pathogens. They can also be used as calculated antibiotic therapy for severe infections. They are administered immediately if the pathogen is still unknown in the case of a severe infection, but can be suspected on the basis of the symptoms present. The rapid start of therapy is intended to prevent complications. In Germany, tigecycline is approved exclusively for the treatment of severe infections. The drug is administered intravenously. Possible areas of use are severe skin and soft tissue infections and complicated infections within the abdominal cavity. In most cases, these complicated infections are acquired in the outpatient setting and are caused by MRSA (meticillin-resistant Staphylococcus aureus). Infections with ESBL-forming pathogens are also an indication for tigecycline. ESBL stands for extended-spectrum beta-lactamases. ESBL-forming bacteria can cleave beta-lactam-containing antibiotics and are thus resistant to penicillins, cephalosporins and monobactams. ESBL-forming bacteria belong to the so-called problem germs. They are responsible for a large number of infections in hospitals. ESBL-forming Klebsiellae and Escherichia coli are particularly significant. So far, tigecycline is still effective against these pathogens. In contrast, the antibiotic has no effect against infections with Pseudomonas aeruginosa.
Risks and side effects
For children and adolescents younger than 18 years, there are not yet any studies on the effectiveness and side effects of tigecycline. However, there is already evidence that tigecycline may interfere with bone formation in children and adolescents, resulting in delayed bone formation. The side effect of tigecycline depends on the dose. Therefore, it is recommended to divide the daily dose into two single doses. Common side effects are nausea and vomiting. In comparison with other antibiotics, increased lethality has been observed. Especially in pneumonia, treatment with tigecycline is associated with a higher lethality rate. The course of the disease is negatively affected especially when superinfection occurs during treatment with tigecycline. A superinfection is a bacterial infection that develops on the basis of a viral infection.Because of the high lethality, a thorough risk-benefit assessment should therefore be made before using tigecycline. If it turns out after the start of therapy that the infection is not part of the approved indications, an alternative antibacterial treatment should be carried out. Unlike many other antibiotics, tigecycline is not metabolized via the so-called cytochrome P450 system. Therefore, there are few interactions between the antibiotic and other drugs. If the anticoagulant warfarin is administered at the same time, the coagulation parameters in the blood must be monitored. It should be noted that the effectiveness of oral contraceptives may be reduced while taking tigecycline.