Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023241 (Legionella)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Erythromycin, first introduced for clinical use 30 years ago, was found to be effective for the treatment of gram-positive bacterial infections. Emergence of resistance and the advent of penicillinase-resistant penicillins limited the use of erythromycin for serious staphylococcal infections; however, erythromycin remains among the drugs of choice for the treatment of acne, infections of the skin and soft tissues, streptococcal pharyngitis, bronchitis, pneumonitis, diphtheria, carriers of pertussis, and, when administered with a sulfonamide, otitis media. Erythromycin is the drug of choice for the empiric treatment of outpatients with pneumonitis. Erythromycin is also the drug of choice for the treatment of Legionella pneumonia and is effective therapy for Chlamydia infections. Other uses of erythromycin include prophylaxis for elective colon operations and treatment of Campylobacter enteritis, genitourinary infections, and some sexually transmitted diseases.
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PMID:Erythromycin: a microbial and clinical perspective after 30 years of clinical use (2). 388 13

Clarithromycin is a new macrolide with a broad spectrum of activity against Gram-positive cocci, Haemophilus influenzae, Moraxella catarrhalis, Mycoplasma, Chlamydia and selected Mycobacteria, Legionella and protozoa. The drug has a half-life of more than 4 hours and thus can be administered in a twice daily schedule. Clarithromycin is well-tolerated in children and adults and produces fewer gastrointestinal side effects than erythromycin. High concentrations of the drug are achieved in plasma and in cells and tissues including tonsil, lung and middle ear fluids. Clinical efficacy has been demonstrated in randomized multicenter trials of infants and children with acute otitis media, streptococcal pharyngitis and infections of skin and skin structures. Results of these comparative trials with randomized patients receiving clarithromycin or standard drugs identified equivalent clinical and bacteriologic outcomes. A higher rate of eradication of group A Streptococcus from the pharynx was achieved with clarithromycin than with penicillin VK. The potential advantages provided by high concentrations of clarithromycin in cells and tissues such as more rapid clinical improvement or shortened dosage schedules are still to be identified.
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PMID:Clarithromycin: where do we go from here? 829 17

Erythromycin and other macrolides have enjoyed a renaissance in the 1970s, 1980s and 1990s secondary to the discovery of "new' pathogens such as Chlamydia, Legionella, Campylobacter and Mycoplasma spp. Erythromycin is an important therapeutic agent in the paediatric age group for several reasons: (a) it exhibits proven efficacy for a wide range of infections (upper and lower respiratory tract infections, skin/skin structure infections, prophylaxis of endocarditis/acute rheumatic fever/ophthalmia neonatorum and pre-colonic surgery, campylobacteriosis, chlamydial and ureaplasmal infections, diphtheria, whooping cough, streptococcal pharyngitis) and gastrointestinal (GI) dysmotility states; (b) intravenous formulations are widely available; and (c) it is available in a number of formulations as a generic product, which is likely to result in significant cost savings. Nevertheless, erythromycin and similar earlier macrolides are characterised by a number of drawbacks including a narrow spectrum of antimicrobial activity, unfavourable pharmacokinetic properties and poor GI tolerability. Newer macrolides such as clarithromycin and azithromycin are useful in serving the needs of paediatric patients who are erythromycin-intolerant or who have infections caused by organisms that are intrinsically erythromycin-resistant, or for which a high percentage of strains are resistant (e.g. Haemophilus influenzae, Helicobacter pylori, Mycobacterium avium complex). In addition, these newer macrolides may be considered as alternatives to oral amoxicillin-clavulanic acid, second or third generation cephalosporins, or erythromycin plus sulphonamide in this patient population. Selection between specific macrolides and between macrolides and other antibiotics in the paediatric population is likely to depend, at least for the immediate future, on separate comparisons of product availability, cost, effectiveness and tolerability profiles.
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PMID:Macrolide antibiotics in paediatric infectious diseases. 870 92

Dirithromycin is a semisynthetic derivative of erythromycin, a 14-membered ring macrolide antibiotic. The drug is converted during absorption and distribution, to an active metabolite 9-(S)-erythromycylamine, which is the predominant compound found in plasma and extravascular tissues. High tissue concentration of erythromycylamine is achieved after oral doses of dirithromycin, with slow release back into the circulation. The mechanism of action of dirithromycin is like that of erythromycin and other macrolides. These compounds inhibit RNA-dependent protein synthesis. It has recently been suggested that all macrolides stimulate dissociation of peptidyl-tRNA from ribosomes during the elongation phase, leading to inhibited protein synthesis. The antimicrobial spectrum of dirithromycin is similar to that of erythromycin, although the drug offers no significant advantage with regard to MIC values. In vitro against Gram-positive isolates, dirithromycin exhibits similar potency to that of clarithromycin, erythromycin, roxithromycin, and clindamycin. In vivo, dirithromycin is active against penicillin-susceptible Staphylococcus aureus, beta-hemolytic streptococci, and Streptococcus pneumoniae. Dirithromycin is as effective as penicillin VK against streptococcal pharyngitis and tonsilitis, and as effective as erythromycin against acute superimposed chronic bronchitis and skin and soft-tissue infections. In comparison with other newer macrolides, dirithromycin has shown similar or lesser in vitro activity. In particular, Haemophilus influenzae, Bacteroides spp., Peptococcus-Peptostreprococcus spp., Clostridium perfringens, Legionella spp., Neisseria gonorrhoeae, and Chlamydia trachomatis were all less sensitive to dirithromycin than azithromycin or clarithromycin. Once-daily oral administration of dirithromycin (500 mg) has been demonstrated to be similar in efficacy to erythromycin (250 mg, 4 times daily), each for approximately 7 days, in the treatment of acute bronchitis or acute-exacerbations of chronic bronchitis in controlled studies. Proven or presumed pathogen eradication rates were 83 and 86% for acute bronchitis patients treated with dirithromycin and erythromycin, respectively. Corresponding bacteriological response rates in acute exacerbations of chronic bronchitis were 75 to 84% with dirithromycin and 75 to 82% with erythromycin. Both agents achieved clinical cure or improvement in over 85% of the patients with either condition. The main advantage of dirithromycin over erythromycin appears to be once-daily administration. Lilly launched dirithromycin in September 1993, in Spain, received approval from FDA in August 1995, and launched it during October 1995.
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PMID:New drugs--reports of new drugs recently approved by the FDA. Dirithromycin. 873 38

Telithromycin is a new ketolide antimicrobial, specifically developed for the treatment of community-acquired respiratory tract infections. It has a wide spectrum of antibacterial activity against common respiratory pathogens including Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. It also has activity against atypical pathogens, such as Chlamydia pneumoniae, Legionella pneumophila and Mycoplasma pneumoniae. Telithromycin maintains activity against beta-lactam and macrolide-resistant respiratory tract pathogens and does not appear to induce cross-resistance to other members of the macrolide-lincosamide-streptogramin (MLS) group of antimicrobials. It demonstrates bactericidal activity against S. pneumoniae and H. influenzae and has a prolonged concentration-dependent post-antibiotic effect (PAE) in vitro. The drug has favourable pharmacokinetics following oral administration. It is well absorbed, achieves good plasma levels and is highly concentrated in pulmonary tissues and white blood cells. In clinical trials, telithromycin given orally at a dose of 800 mg once daily for 5 - 10 days was as effective as comparator antimicrobials for the treatment of adults with community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute maxillary sinusitis and group A-beta-haemolytic streptococcal pharyngitis or tonsillitis. The adverse events and safety profile were similar to comparator antimicrobials. The most common adverse events were diarrhoea, nausea, headache and dizziness. Telithromycin should provide an effective, convenient and well-tolerated once-daily oral therapy for treatment of respiratory infections.
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PMID:Telithromycin: a new ketolide antimicrobial for treatment of respiratory tract infections. 1117 47