Clarithromycin is a macrolide antibiotic of the semi-synthetic type. Its antibacterial properties are due to the suppression of the binding of proteins due to synthesis with the ribosomal 50S subunit in substance sensitive microbes.
Often has a bacteriostatic effect, but individual microbes can also be bactericidal. The drug has a powerful specific effect on a relatively large range of anaerobes and aerobes (both gram-positive and gram-negative). Minimal depressive index in clarithromycin is often 2 times lower than the same value for erythromycin.
Clarithromycin in vitro studies demonstrates high efficacy relative to legionella pneumophila and mycoplasma pneumonia. The in vitro and in vivo indices show the potent effect of clarithromycin on drug-specific strains of mycobacteria. In addition, these tests also show that strains of enterobacteria and pseudomonads (as well as gram-negative microorganisms that do not produce lactose) are resistant to clarithromycin.
Clarithromycin, in in vitro tests, as well as in drug practice, actively affects most strains of microbes described below:
- Gram-positive aerobes: Staphylococcus aureus, pneumococcus, streptococcus pyogenes and listeria monocytogenes;
- Gram-negative aerobes: Influenza rod, Haemophilus parainfluenzae, moraxella cataris, gonococcus and Legionella pneumophile;
- other bacteria: mycoplasma pneumonia and chlamydophile pneumonia (TWAR);
- mycobacteria: Hansen's stick, Mycobacterium Kansasi, Mycobacterium chelonae, Mycobacterium fortuitum, and Mycobacterium avium somplex, which includes Mycobacterium intracellulare and Mycobacterium avium.
β-lactamase microbes do not affect the properties of clarithromycin.
Most of methicillin, as well as oxacillin-resistant staphylococcal strains, is resistant to clarithromycin.
Clarithromycin in vitro studies showed an active effect on most of the strains of the bacteria described below, but the safety and drug efficacy of using this drug was not established:
- Gram-positive aerobes: streptococcus agalactia, streptococci types C, F, as well as G, and from the Viridans group;
- Gram-negative aerobes: pertussis and multicid paste;
- other bacteria: Chlamydia trachomatis;
- Gram-positive anaerobes: clostridium perfringence, Peptococcus niger and propionibacterium acne;
- Gram-negative anaerobes: Bacteriodes melaninogenicus;
- spirochaetes: borrelia of Burgdorfer and pale treponema;
- Campylobacterium: Campylobacter effini.
Clarithromycin has bactericidal properties, directed at individual strains of microbes: influenza rod, pneumococcus, streptococcus pyogenes, streptococcus agalactia, moraxella cataris, gonococcus, helicobacter pylori and campylobacter.
The main product of substance disintegration is the element 14-hydroxyclarithromycin, which exhibits microbiological activity. In the majority of microbes this activity is equal to that of the parent substance, or less than 1-2 times (except for the influenza rod, against which the efficiency of the decay product is twice as high). Tests in vitro and also in vivo have shown that the parent substance with its main degradation product has synergistic or additive properties with respect to the hemophilic rod (this depends on the bacterial strain).