Antimicrobials macrolide antibiotics

Antimicrobial agents as well as macrolide antibiotics and fluoroquinolones used in human and veterinary medicine are of particular interest due to their potential for... 

Antimicrobials are over prescribed for exacerbations of asthma. Respiratory tract infections do cause increased airflow obstruction and hyperresponsiveness, but viral rather than bacterial pathogens are the commonest culprits. Antimicrobials should be prescribed only if there is high suspicion of a bacterial respiratory tract infection, e.g. purulent sputum. Note that macrolide antibiotics, such as erythromycin and clarithromycin, interfere with theophylline metabolism. 

Antimicrobial compounds attracted special attention in this respect. In an early study, Hirsch et al. [55] determined macrolide antibiotics, sulfonamides, tetracyclines, betalactam antibiotics, trimethoprim, and chloramphenicol in different water compartments using LC-ESI-MS-MS. Three different gradient LC methods were developed for the 18 target compounds. Quantitation limits of 50 ng/1 were achieved for tetracyclines and 20 ng/1 for all other compounds after SPE. 

Erythromycin estolate in conjunction with rifampin (both drugs administered orally) can be recommended for the treatment of Rhodococcus equi pneumonia in foals. Early diagnosis of the infection and prompt initiation of therapy considerably increase the effectiveness of treatment. Apart from this specific indication, macrolide antibiotics (including erythromycin) and lincosamides (lincomycin and clindamycin) are contra-indicated in horses. Antimicrobial agents in these classes can cause severe disturbance of the balance between commensal bacterial flora in the colon of the horse. 

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,... 

Erythromycin is a macrolide antibiotic widely used for the treatment of upper and lower respiratory tract infections. Recent reports further showed that EM and its analogues are effective for the treatment of chronic airway diseases such as DPB, bronchial asthma, and chronic sinusitis [5, 15, 32]. This effectiveness is considered to be apart from their antimicrobial actions, because they are effective at half of the recommended dosage and even in cases without concomitant infection. Its precise mechanisms, however, remain unclear. Several cytokines including IL-1, TNF-a, and IL-8 have been reported to be elevated in HALF from patients with such airway inflammatory diseases (Table II), and to be decreased... 

McDaniel R, Katz L (2001). Genetic engineering of novel macrolide antibiotics. In Lohner K (ed.), Development of Novel Antimicrobial Agents Emerging Strategies. Horizon Scientific Press Norwich, U.K., pp. 45-60. 

Research activity in the macrolide antibiotic class has been intense recently in attempts to reduce side effects and to broaden their antimicrobial spectra. The ketolides are a group of agents that are characterized by oxidation of the 3-position from an alcohol to a ketone. They are active against a significant number of erythromycin-resistant microorganisms. Recent investigation has been intense and a new agent has been introduced. 

Oleandoniycin. C35H ,NO,2, Mr 687.87, mp. 110°C, [a][> -65° (CH3OH). Internationa free name for a 14-membered macrolide antibiotic with a broad spectrum of antimicrobial activity isolated from cultures of Streptomyces antibioticus. O. is readily soluble in methanol, ethanol, butanol, acetone, less soluble in wa-... 

The macrolide antibiotics comprise an important and well-established class of antimicrobial agents. Several members from this large class have achieved prominent positions in either clinical or veterinary medicine. An excellent book covering many aspects of the macrolides before 1984 has been published [1]. In addition, several recent reviews have disQussed current usage of these antimicrobial agents [2, 3, 4, 5, 6]. 

Oleandomycin, a 14-membered ring macrolide antibiotic, was isolated in 1956 from fermentation broths of Streptomyces antibioticus [360]. Some years later, oleandomycin was assigned the structure 340 on the basis of its chemical degradation [361]. Oleandomycin is effective, but less potently, against the same spectrum of bacteria as erythromycin, namely Gram-positive bacteria such as staphylococci, streptococci, and pneumococci. The antimicrobial activity of oleandomycin, when combined with tetracycline, is potentiated. In fact, in such a combination it is sold as an antibacterial agent for upper and lower respiratory tract infection. 

Erythromycin, from the actinomycete Saccharo-polyspora (formerly Streptomyces) erythraea, is the first member of this family of antibiotics to be marketed and successfully used clinically to treat infections in humans. It has an antimicrobial spectrum at least as wide as the penicillins, and interestingly, from our perspective, it is often used as a replacement for patients allergic to that group of drags. Besides erythromycin, other members of the macrolide family of antibiotics that are clinically useful include azithromycin, clarithromycin, dirithromycin, roxithromycin, telithromycin (these six are approved by the FDA), oleandomycin, and spiramycin. Clarithromycin, dirithromycin, and roxithromycin and the azalide azithromycin are more recent members of the group and can be regarded as newer generation macrolide antibiotics. 

Ansamycin Antibiotics.—The ansa macrolide antibiotics, formerly composed of the rifamycins, streptovaricins, tolypomycins, and geldanamycin, but also now including the maytansines (see below), have aroused considerable interest as antiviral and antimicrobial agents, and as inhibitors of RNA tumour virus reverse transciptases. The chemistry etc. of this interesting class of antibiotics has been the subject of a recent review by Rinehart. Streptovaricins. Rinehart and collaborators have re-examined the structures... 

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