Macrolides are antibiotics, in the structure of which a macrocyclic lactone ring is revealed. Depending on the number of carbon atoms, they are divided into 14-membered (clarithromycin, roxithromycin, erythromycin), 15-membered (azithromycin), 16-membered (josamycin, midecamycin, spiramycin). These substances are most active against intracellular parasites (chlamydia, mycoplasmas, legionella, campylobacter) and gram-positive cocci (aureus, pyogenesis). Macrolides are antibiotics related to the least toxic compounds.
Recently, there has been an increase in the resistance of microorganisms to the action of drugs of this class. It has been scientifically proven that in some cases 16-membered macrolides (midecamycin, josamycin, spiramycin) remain active against pyogenic streptococci and pneumococci that are resistant to 14-membered (clarithromycin, roxithromycin, erythromycin) and 15-membered (azithromycin) pharmaceuticals. Macrolides are drugs that act on pathogens of diphtheria and whooping cough, legionella, campylobacter, moraxella, listeria, chlamydia, spirochetes, mycoplasmas, ureplasma. It should be noted that microorganisms belonging to the family Pseudomonas and Enterobacteriacea have natural resistance to all macrolides.
Mechanism of action
Drugs of this group disrupt protein biosynthesis on ribosomes of microbial cells. Macrolides are antibiotics that exhibit a bacteriostatic effect. When prescribing maximum doses, they exhibit a bactericidal effect against pneumococcus, diphtheria and pertussis pathogens. These medications may also have an immunomodulatory and anti-inflammatory effect.
These drugs are easily absorbed in the gastrointestinal canal, their concentration is affected by the concentration of the bioactive substance in the drug, the dosage form, as well as the presence of food and its amount. Food significantly reduces the bioavailability of erythromycin, azithromycin, roxithromycin and medicicamycin, with virtually no effect on the bioavailability of spiramycin, josamycin and clarithromycin.
Macrolides are antibiotics, the concentration of which in the blood plasma is significantly lower compared to tissues. Therefore, they are also called tissue antibiotics. A new generation of macrolides easily binds to plasma proteins. The highest degree of plasma protein binding is observed with rhodomyxin (more than 90%), the smallest - with spiramycin (less than 20%). Macrolide preparations are very well distributed throughout the body, while creating maximum concentrations in various organs and tissues. They easily penetrate the cell membrane, while creating limiting intracellular clusters.
Exchange products are excreted mainly with bile and urine. After using these antibiotics, side effects can occur in the form of headache, nausea, vomiting, diarrhea, general weakness, malaise, allergic reactions. Antibiotics of this group are prescribed for infectious diseases of the upper (acute sinusitis, streptococcal tonsillopharyngitis) and lower (atypical pneumonia, chronic bronchitis) airways, whooping cough, diphtheria, syphilis, chlamydia, venereal lymphogranuloma, periostitis, periodontitis syrupylozteriosis, gastroenteritis, severe gastrointestinosis cryptosporidiosis.
It is undesirable to prescribe these antibiotics during pregnancy. The negative effect of clarithromycin on the fetus has been scientifically proven. Josamycin, spiramycin and erythromycin do not adversely affect the fetus, so they can be used even during pregnancy. Azithromycin in this period is used in case of emergency. Most macrolide preparations pass into mother's milk. During breastfeeding, it is best to refrain from using these antibiotics.