Roxithromycin

Indications

Roxithromycin is indicated for the treatment of infections affecting the respiratory tract, urinary tract, and soft tissues. This antibiotic is specifically effective against a range of bacterial infections in these areas, making it a valuable option in clinical settings for managing such conditions.

Pharmacodynamics

Roxithromycin exhibits a broad antibacterial spectrum in vitro, which includes activity against pathogens such as Streptococcus agalactiae, Streptococcus pneumoniae (Pneumococcus), and Neisseria meningitides (Meningococcus). It is also effective against Listeria monocytogenes, Mycoplasma pneumoniae, Chlamydia trachomatis, Ureaplasma urealyticum, Legionella pneumophila, Helicobacter species, Gardnerella vaginalis, Bordetella pertussis, Moraxella catarrhalis (Branhamella catarrhalis), and Haemophilus ducreyi. Roxithromycin is concentrated within polymorphonuclear leukocytes and macrophages, achieving higher intracellular concentrations than extracellular ones. It enhances the adhesive and chemotactic functions of these cells, facilitating phagocytosis and the subsequent lysis of bacteria, while also demonstrating intracellular bactericidal activity.

Absorption

Roxithromycin is rapidly absorbed and distributed into most tissues and phagocytes, ensuring that therapeutic concentrations are reached quickly throughout the body. This rapid absorption aids in the effectiveness of the drug against targeted infections.

Metabolism

Roxithromycin undergoes partial metabolism in the liver, with more than half of the parent compound being excreted unchanged. Its metabolites are excreted via urine and feces, and include the major metabolite descladinose roxithromycin, alongside minor metabolites N-mono and N-di-demethyl roxithromycin. The distribution of the parent drug and its metabolites is similar across both urine and fecal excretions.

Mechanism of Action

Roxithromycin functions by inhibiting bacterial proliferation through disruption of protein synthesis. It achieves this by binding to the 50S subunit of the bacterial ribosome, thereby hindering the translocation of peptides and effectively preventing their assembly.