Azithromycin is a broad-spectrum macrolide antibiotic with a long half-life and a high degree of tissue penetration. It was initially approved by the FDA in 1991.
It is primarily used for the treatment of respiratory, enteric and genitourinary infections and may be used instead of other macrolides for some sexually transmitted and enteric infections. It is structurally related to erythromycin.
Azithromycin [9-deoxo-9a-aza-9a-methyl-9a-homoerythromycin] is a part of the azalide subclass of macrolides, and contains a 15-membered ring, with a methyl-substituted nitrogen instead of a carbonyl group at the 9a position on the aglycone ring, which allows for the prevention of its metabolism. This differentiates azithromycin from other types of macrolides.
Azithromycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria in order to prevent the development antimicrobial resistance and maintain the efficacy of azithromycin.
Macrolides stop bacterial growth by inhibiting protein synthesis and translation, treating bacterial infections. Azithromycin has additional immunomodulatory effects and has been used in chronic respiratory inflammatory diseases for this purpose.
Associated Conditions: Acute Bacterial Sinusitis (ABS), Acute Otitis Media, Acute bacterial exacerbation of COPD caused by Haemophilus Influenza Infections, Moraxella Catarrhalis Infection, Streptococcus Pneumoniae Infections, Acute maxillary sinusitis caused by M. catarrhalis, Cervicitis, Chancroid, Community Acquired Pneumonia (CAP), Conjunctivitis, Bacterial, Genital Ulcer Disease (GUD), Pelvic Inflammatory Disease (PID), Pharyngitis, Streptococcal Pharyngitis, Streptococcal tonsillitis, Tonsillitis bacterial, Uncomplicated Skin and Skin Structure Infections, Urethritis.
In order to replicate, bacteria require a specific process of protein synthesis, enabled by ribosomal proteins. Azithromycin binds to the 23S rRNA of the bacterial 50S ribosomal subunit. It stops bacterial protein synthesis by inhibiting the transpeptidation/translocation step of protein synthesis and by inhibiting the assembly of the 50S ribosomal subunit.
This results in the control of various bacterial infections. The strong affinity of macrolides, including azithromycin, for bacterial ribosomes, is consistent with their broad‐spectrum antibacterial activities.
Azithromycin is highly stable at a low pH, giving it a longer serum half-life and increasing its concentrations in tissues compared to erythromycin.
Metabolism: In vitro and in vivo studies to assess the metabolism of azithromycin have not been performed, however, this drug is eliminated by the liver.
Absorption: Bioavailability of azithromycin is 37% following oral administration. Absorption is not affected by food. Macrolide absorption in the intestines is believed to be mediated by P-glycoprotein (ABCB1) efflux transporters, which are known to be encoded by the ABCB1 gene.
Route of elimination: Biliary excretion of azithromycin, primarily as unchanged drug, is a major route of elimination. Over a 1 week period, approximately 6% of the administered dose is found as unchanged drug in urine.
Half life: Terminal elimination half-life: 68 hours
All medicines may cause side effects, but many people have no, or minor, side effects.Some medical conditions may interact with Azithromycin.
Tell your doctor or pharmacist if you have any medical conditions.
Common azithromycin side effects may include: diarrhea, nausea, vomiting, stomach pain or headache.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.
