Battu Rakesh *1, Jaladi Himaja1
1. Department of Pharmacy Practice, Bharathi College of Pharmacy, Bharathinagara, K.M.Doddi, Mandya, Karnataka, India-571422.
Azithromycin is a semi-synthetic 15-membered azalide antibiotics derived from erythromycin. Azithromycin is a macrolide antibiotic suitable for the management of a number of bacterial infections. This comprises respiratory tract infections, skin infections, chlamydia infections, and syphilis. It may also be used during pregnancy to prevent Group B streptococcal infection in the new-born. It can be given intravenously and by mouth. Azithromycin displays bacteriostatic activity or inhibits growth of bacteria, principally at higher concentration, however the mechanism is not completely understood. By binding to the 50s subunit of the bacterial rRNA complex, protein synthesis and subsequent structure and function processes critical for life or replication are inhibited. Azithromycin is very rapidly absorbed, and diffuses into most tissues and phagocytes. Usual dosage range: -Oral: 500 mg once daily. Azithromycin has pharmacokinetics that allows shorter dosing schedules because of prolonged tissue levels. The bioavailability of azithromycin is approximately 37 % in humans. Tissue concentrations exceed serum concentrations by as far as 100-fold after a single 500 mg oral dose. Macrophages and polymorphonuclear leucocytes concentrate azithromycin at levels greater than those found in tissues themselves. High concentrations of drug are found in tissues such as tonsil, lung, prostate, liver and lymph nodes with relatively low concentrations in fat and muscle. As with all antimicrobial agents, pseudomembranous colitis can occur during and up to several weeks after azithromycin therapy. However, it has a few side effects like mild diarrhoea, nausea, vomiting, abdominal pain. Azithromycin can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm. Evidence indicates that azithromycin is largely excreted in the faeces unchanged, with a small percentage appearing in the urine. Exacerbations of myasthenia gravis have also been reported with the use of azithromycin. Azithromycin’s pharmacokinetics and tolerability make it particularly useful in the treatment of sexually transmitted infections, intracellular enteric pathogens and for prophylaxis of mycobacterial infection. It is furthermore beneficial for treating a variety of respiratory diseases. Unfettered use of azithromycin, particularly for its immunomodulatory properties, is of concern in light of macrolide resistance.
Keywords: Azithromycin, Macrolide Antibiotic, Chlamydia Infections, Syphilis, Bacteriostatic, Phagocytes, Pseudomembranous colitis and Myasthenia Gravis.