Roxithromycin is a macrolide antibiotic. It is a semi-synthetic 14-membered-ring macrolide antibiotic in which the erythronolide A lactone ring has been altered to prevent inactivation in the gastric milieu. Like other macrolides, roxithromycin displays a significant post-antibiotic effect which is dependent on the pathogens under study, the concentration of roxithromycin and the duration of exposure. In vivo, roxithromycin is as effective or more effective than other macrolides in a wide range of infections.
Roxithromycin is very similar in composition, chemical structure (semi-synthetic) and mechanism of action to erythromycin, azithromycin, or clarithromycin. Antibiotics such as roxithromycin can often be prescribed for several different infections, including some STDs, upper and lower respiratory tract infections and asthma, gum infections like gingivitis, and bacterial infections associated with stomach and intestinal ulcers. Roxithromycin is absorbed well into the gastro-intestinal tract, with few side effects, and actively responds to the presence of cryptosporidium, pneumocystis carinii (PCP), toxoplasma gondii, and Mycobacterium Avium (MAC). The in-vitro activity of roxithromycin is well documented and similar to that of other macrolide antibiotics. Roxithromycin is active against gram-positive and gram- negative cocci, gram-positive bacilli and some gram-negative bacilli, but has no significant effect on the predominant faecal flora. It also displays good activity against atypical pathogens, such as Mycobacterium avium complex, Helicobacter pylori and Borrelia spp. It penetrates and accumulates within cells, such as macrophages and polymorphonuclear neutrophils (PMNs), where it is distributed between the cytosol and cellular granules. Once inside the cells, it is active against intracellular pathogens, such as Legionella, Chlamydia, Mycobacterium, Rickettsia and Borrelia spp.
Roxithromycin is active against Gram-positive bacteria like staphylococci, streptococci, listeria, corynebacteria; Gram-negative bacteria such as gonococci, Haemophilus influenzae, Haemophilus ducreyi, Legionella, campylobacter, and atypical pathogens like Mycoplasma and Chlamydia. Roxithromycin has been found useful in the treatment of upper and lower respiratory, otorhinolaryngological, skin, dental and genital infections. It is well tolerated by adults and children.