Atsitromysiini

Atsitromysiini is a macrolide antibiotic belonging to the azalide subclass. It is a semisynthetic derivative of erythromycin, designed to improve acid stability, tissue distribution, and dosing convenience. The drug exerts its antibacterial effect by binding to the 50S ribosomal subunit, inhibiting translocation and thereby blocking protein synthesis in susceptible bacteria.

Compared with erythromycin, atsitromysiini shows a broader tissue distribution and a longer half-life, which supports once-daily dosing and shorter treatment courses. It achieves high intracellular and tissue concentrations, particularly in the respiratory tract and phagocytes, contributing to its effectiveness in respiratory infections, certain skin and soft-tissue infections, and some sexually transmitted infections. The antimicrobial spectrum includes many Gram-positive bacteria and several atypical pathogens (such as Mycoplasma and Chlamydophila species). It is less active against many Gram-negative bacteria and does not cover Pseudomonas aeruginosa.

Common adverse effects include gastrointestinal symptoms such as nausea, diarrhea, and abdominal pain. There is a risk of QT interval prolongation and drug interactions with other medications, especially other agents that affect cardiac repolarization. As with other macrolides, resistance can emerge through methylation of the 50S ribosomal target, reducing binding of the drug.

Historically, atsitromysiini was developed to improve tolerability and pharmacokinetic properties relative to earlier macrolides and has seen widespread use in various regions under different brand names. It remains a commonly referenced azalide in medical literature and clinical practice.