Azithromycin is an azalide antibiotic, subclass of the macrolide class of antibiotics. Azithromycin acts by binding to the 50s ribosomal subunit of susceptible organisms and thus interferes with microbial protein synthesis. Azithromycin demonstrated activity in vitro, against a wide range of gram-positive and gram-negative bacteria including: Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes (Group A) and other Streptococcal species; Haemophilus influenzae and parainfluenzae; Moraxella catarrhalis; anaerobes including Bacteroides fragilis, Escherichia coli, Bordetella pertussis, Bordetella parapertussis, Borrelia burgdorferi, Haemophilus ducreyi, Neisseria gonorrhoeae and Chlamydia trachomatis. Azithromycin also demonstrates activity in vitro against Legionella pneumophila, Mycoplasma pneumoniae and hominis; Campylobacter sp., Toxoplasma gondii and Treponema pallidum. Administration: Azithromycin can be taken with or without food. Interaction:Antacids: Peak serum levels but not the total extent of absorption are reduced by aluminium and magnesium containing antacids in the stomach. Azithromycin should therefore be taken at least 1 hour before or 2 hours after taking these antacids. Ergot Derivatives: Because of the theoretical possibility of ergotism, concomitant administration of ergot derivatives and Azithromycin should be avoided.
Digoxin & Cyclosporin:
Macrolides have been known to increase the plasma concentration of Digoxin & Cyclosporin and so caution should be exercised while co-administration is necessary. Anti-Histamines: A potentially life threatening interaction between erythromycin and terfenadine or astemizole have been reported. Although such an interaction with Azithromycin is not established yet, it is wise to avoid concomitant use of Azithromycin and terfenadine or astemizole. Contraindications: Azithromycin is contraindicated in patients hypersensitive to Azithromycin or any other macrolide antibiotic. Co-administration of ergot derivatives and Azithromycin is contraindicated. Azithromycin is contraindicated in patients with hepatic diseases. Side Effect: Azithromycin is well tolerated with a low incidence of side effects. The side effects include nausea, vomiting, abdominal discomfort (pain/cramps), flatulence, diarrhoea, headache, dizziness, and skin rashes and are reversible upon discontinuation of therapy.
Pregnancy & Lactation:
Recent clinical studies have recommended that Azithromycin should be considered for the initial treatment of chlamydial cervicitis in pregnancy. In other infections. Azithromycin should be used only when clearly needed. It is not known whether Azithromycin is excreted in breast milk. Exercise caution when administering to a nursing woman.Precautions:As with any antibiotic, observation for signs of superinfection with non-susceptible organisms, including fungi, is recommended. No dose adjustment is needed in patients with renal impairment.
There is no data on overdosage with Azithromycin. Typical symptoms of overdosage with macrolide antibiotics include hearing loss, severe nausea, vomiting and diarrhoea. Gastric lavage and general supportive measures are indicated.