Macrolides - antibiotics / General characteristics and application

Macrolides are antibiotics, in the structure of which a macrocyclic lactone ring is identified. 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 in relation to intracellular parasites (chlamydia, mycoplasma, 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-member macrolides (midecamycin, josamycin, spiramycin) retain activity against pyogenic streptococci and pneumococci that are resistant to 14-member (clarithromycin, roxithromycin, erythromycin) and 15-member (azithromycin) pharmaceuticals. Macrolides are drugs that act on the pathogens of diphtheria and whooping cough, legionella, campylobacter, moraxella, listeria, chlamydia, spirochetes, mycoplasmas, ureplazmy. It should be noted that microorganisms belonging to the family Pseudomonas and Enterobacteriaceae possess natural resistance to all macrolides.

Mechanism of action

Preparations of this group disrupt the biosynthesis of the protein on the ribosomes of the microbial cell. Macrolides are antibiotics that exhibit bacteriostatic action. When the maximum doses are prescribed, they show a bactericidal effect against pneumococcus, diphtheria and pertussis. These drugs can also exhibit an immunomodulatory and anti-inflammatory effect.

These drugs are easily absorbed in the gastrointestinal canal, their adsorption is influenced by the concentration of bioactive substance in the preparation, the dosage form, and also the presence of food and its quantity. Food significantly reduces the bioavailability of erythromycin, azithromycin, roxithromycin and medikamycin, with virtually no effect on the bioavailability of spiramycin, josamycin and clarithromycin.

Macrolides are antibiotics, the concentration of which in the blood plasma is much lower compared to tissues. Therefore, they are also called tissue antibiotics. Macrolides of the new generation are easily associated with blood plasma proteins. The highest degree of binding of plasma proteins is noted with rhodomixin (more than 90%), the lowest - with spiramycin (less than 20%). Preparations of macrolides are very well distributed throughout the body, creating maximum concentrations in various organs and tissues. They easily penetrate the cell membrane, creating at the same time limiting intracellular clusters.

The products of metabolism are mainly derived from bile and urine. After the use of these antibiotics, there may be side effects 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 group (acute sinusitis, streptococcal tonsillopharyngitis) and lower (atypical pneumonia, chronic bronchitis) of the respiratory tract, pertussis, diphtheria, syphilis, chlamydia, venereal lymphogranuloma, periostitis, periodontitis, severe acne, campylobacterial gastroenteritis, toxoplasmosis , 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 have a detrimental effect on the fetus, so they can be used even during pregnancy. Azithromycin in this period is used in case of emergency. Most of the drugs-macrolides penetrate into the mother's milk. During breastfeeding, it is best to refrain from using these antibiotics.