Azithromycin antimicrobial activity

Roxithromycin, clarithromycin, azithromycin and dirithromycin are more recently developed macrolides with similar antimicrobial activity to erythromycin. However they are better absorbed, have longer elimination half-lives and lower incidence of gastrointestinal side-effects. Azithromycin and... 

Long to, and higher tissue concentrations allow qd dosing however, the improved antimicrobial activity against Haemophilus influenzae and lower incidence of G1 adverse effects have not been realized with this agent azithromycin probably best choice pending further comparisons... 

Peters DH, Friedel HA, McTavish D. Azithromycin. A review of its antimicrobial activity, pharmacokinetic properties and clinical efficacy. Drngs 1992 44(5) 750-99. 

Other macrolide antimicrobials, such as clarithromycin and azithromycin, appear to interact with motilin receptors. Current investigations center on developing motilides that lack antimicrobial activity, thus not disrupting the normal intestinal flora, but have more potent effects on motility. Isolation and purification of motilin receptors will facilitate the development of drugs that have highly specific motilide activity. 

Azithromycin is essentially unchanged within the body and has no known active metabolites [78], Data derived from the rat and dog suggest that only a small amount of systemically absorbed drug is metabolized, primarily via deme-thylation at 3 -A-dimethylamino group [91]. It has been suggested that as many as 10 metabolites of azithromycin appear in the bile, all of which possess insignificant antimicrobial activity [78]. To date, published descriptions of azithromycin disposition characteristics fail to delineate its metabolic fate and the activity and fate of any metabolites in humans [13]. Azithromycin does not induce cytochrome P-450 enzymes [46]. 

Macrolide antibiotics are a homogeneous group of antimicrobial drugs that have been used to treat clinical infections for several decades. The most clinically useful classification of the macrolides is based on the size of the lactone ring that forms the chemical nucleus of each macrolide molecule [1, 2]. The 14- and 15-membered macrolides include erythromycin, clarithromycin, dirithromycin, roxithromycin, and azithromycin. Erythromycin is the oldest and still the most important of the macrolide antibiotics because it is a useful alternative to penicillin G. It is one of the safest antibiotics available. Clarithromycin and azithromycin have shown some advantages over erythromycin in their antibacterial activity,... 

Currently, azithromycin, clarithromycin, and erythromycin are the most commonly prescribed macrolide antimicrobial agents. The macrolides exhibit bacterio-static/bactericidal activity against a variety of Gram-positive and to a more limited extent Gram-negative pathogens. The pharmacokinetic profiles of the macrolides vary considerably. 

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