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)

The chemistry, mechanism of action, antimicrobial spectrum, pharmacokinetics, clinical efficacy, adverse effects, drug interactions, and dosage and administration of clarithromycin and azithromycin are described. Clarithromycin and azithromycin are new macrolide antibiotics that are similar in structure to erythromycin. Compared with erythromycin, clarithromycin demonstrates increased activity against Staphylococcus aureus, streptococci, Legionella pneumophila, Moraxella catarrhalis, and Chlamydia trachomatis. Clarithromycin also has in vitro activity against Mycobacterium avium complex (MAC) and Toxoplasma gondii. Azithromycin has increased gram-negative activity compared with erythromycin, including activity against Haemophilus influenzae, while maintaining activity against gram-positive organisms. Azithromycin also has activity against sexually transmitted organisms including Chlamydia trachomatis. The pharmacokinetic profiles of clarithromycin and azithromycin are characterized by good oral bioavailability, excellent tissue penetration and persistence, and long elimination half-lives, which allow for once-daily or twice-daily dosing. Initial data show that clarithromycin and azithromycin are effective for the treatment of upper-respiratory-tract and lower-respiratory-tract infections and infections of the skin and skin structures. Azithromycin has been shown to be effective for the treatment of sexually transmitted diseases caused by Chlamydia trachomatis. Clarithromycin and azithromycin have been used to treat MAC and Toxoplasma infections in patients with the acquired immunodeficiency syndrome. The most frequently reported adverse effects for both agents have been nausea, diarrhea, and abdominal pain. Oral formulations of clarithromycin and azithromycin have recently been approved by the FDA. Clarithromycin and azithromycin are new macrolide antibiotics that have potential advantages over erythromycin; however, the role of these agents will be better defined as results of more ongoing trials become available for evaluation.
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PMID:Clarithromycin and azithromycin: new macrolide antibiotics. 151 40

Since the discovery of Legionella pneumophila in the late 1970s, this organism and other Legionella sp have been an important cause of pneumonia in solid organ transplant recipients. Legionella sp are obligate aerobes that require a source of amino acids, iron, and L-cystine. Growth is enhanced in a 5% CO2 atmosphere at 37 degrees C in the presence of charcoal. Legionella sp reside in water supplies and hospital outbreaks associated with contaminated water have been described. Transplant recipients are particularly susceptible to Legionella infection. Legionella pneumonia tends to occur within several weeks after transplantation and frequently coincides with episodes of rejection. A prodrome of influenza-like symptoms is followed by a sometimes "explosive" pneumonia with patchy lobular or interstitial infiltrates on chest radiograph. High fever, abdominal pain, and mental status changes are sometimes seen. Diagnosis is made by examination of respiratory secretions by the direct fluorescent antibody technique or culture of the organism. Intravenous erythromycin is the treatment of choice. Rifampin is added if there is a lack of response. Both erythromycin and rifampin have important and opposite effects on cyclosporine metabolism, which may result, respectively, in increased cyclosporine toxicity or graft loss. Patients who must continue cyclosporine will, therefore, require frequent monitoring of cyclosporine levels.
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PMID:Legionella infection in transplant patients. 218 18

Between August 1982 and December 1985, seven patients at a children's hospital developed hospital-acquired pneumonia caused by Legionella pneumophila. Demographic data included the following: mean age 12.3 years (range 9 months to 20.5 years); male/female ratio 5:2; all patients were white. Some previously identified risk factors present in our patients included high-dose corticosteroid therapy (five patients), other immunosuppressive therapy (four), and chronic lung (five) or kidney (three) disease. Symptoms and signs included rapid onset, fever, cough, pleuritic chest pain, dyspnea, abdominal pain, diarrhea, and headache. Rhinitis, myalgia, and neurologic abnormalities were not noted. Chest roentgenograms revealed single-lobe consolidation in three patients, diffuse bilateral alveolar infiltrates in three, and pleural effusion in three. All patients were treated with erythromycin; three patients also received rifampin. Tracheal intubation and mechanical ventilation were required by four patients. Six patients improved after therapy. One child died of persistent lung disease 1 month after the onset of legionnaires disease. L. pneumophila was isolated from potable water in the hospital. Aerosol equipment cleansed with tap water and the showers were implicated as means of exposure by patients to contaminated potable water. No new nosocomial cases were seen after immunocompromised children were prohibited from taking showers, and sterile water was used to cleanse equipment for administering aerosol medications.
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PMID:Nosocomial legionnaires disease in a children's hospital. 273 94

Serial chest radiographs from 34 confirmed cases of legionnaire disease diagnosed between February 1979 and June 1981 were reviewed. Initial involvement was most often a peripheral patchy alveolar infiltrate (76%, 26/34) with progression to consolidative pneumonia in 70% (18/26) of these cases. Initial or eventual involvement of noncontiguous lobes (50%, 17/34) was common. Bilateral changes developed in 50% of cases and bilateral diffuse disease developed in 12%. Pleural effusions attributable to legionnaire disease occurred in 32% of the patients. Definite clearing took longer than 2 weeks in 50% of treated patients. The severity of radiographic abnormality correlated with the presence of Legionella pneumophila detectable in sputum by direct immunofluorescence (p less than 0.001). No correlation of radiographic severity to smoking, immunosuppression, advanced age, race, or underlying disease, nor to symptoms of abdominal pain, diarrhea, neurologic abnormalities or high fever, nor to laboratory data including hyponatremia, leukocytosis, or hematuria was found. A comparative review of the literature is provided.
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PMID:Clinicoradiographic correlation with the extent of Legionnaire disease. 660 15

In an attempt to ascertain the incidence of Legionnaires' disease at our hospital, a prospective case-control pneumonia study was conducted for 11 months. Specialized diagnostic tests for Legionella pneumophila, including serologic study, direct immunofluorescent examination, and selective culture, were made routinely available in our hospital. To our surprise, L. pneumophila was the most common cause of pneumonia (22.5 percent) attributable to a single pathogen, followed by Streptococcus pneumoniae (10.6 percent). In 68.8 percent of the cases, Legionnaires' pneumonia was hospital-acquired. In contrast to other investigators, we found that abdominal pain, diarrhea, neurologic signs, abnormal liver function results, hypophosphatemia, and hematuria did not occur significantly more frequently in pneumonia caused by L. pneumophila than in that caused by other microorganisms. However, hyponatremia within five days of onset of pneumonia occurred significantly more frequently in Legionnaires' disease (p less than 0.0001). Since the clinical presentation is nonspecific, specialized laboratory tests are necessary to make the diagnosis. As a result of our experience, we suggest an approach using serologic tests as a screen to determine whether more specialized tests for Legionnaires' disease should be introduced into a hospital without previously recognized cases of Legionnaires' disease.
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PMID:Legionnaires' disease: new clinical perspective from a prospective pneumonia study. 712 63

In a double-blind, double-dummy, multicentre study the efficacy and safety of dirithromycin 500 mg/day given orally once daily for 10-14 days were compared with those of erythromycin 1000 mg/day given orally four times daily for 10-14 days in patients with bacterial pneumonia. At 3-5 days post-therapy, 90 dirithromycin- and 83 erythromycin-treated patients were evaluable; the main reason for non-evaluability was failure to isolate the causative organism. Symptomatic responses were favourable in 94.5% of dirithromycin- and 100% of erythromycin-treated patients at post-therapy. At late post-therapy (2-3 weeks after completion of treatment), symptomatic responses were favourable in 98.7% of dirithromycin- and 94.8% of erythromycin-treated patients. At post-therapy, 63.3% of dirithromycin- and 50.6% of erythromycin-treated patients were unable to be evaluated bacteriologically, mainly due to Mycoplasma pneumoniae or Legionella pneumophila being assessed serologically. In the remaining evaluable patients treated with dirithromycin and erythromycin, bacteriological responses were favourable in 91.4% and 87.8%, respectively. At late post-therapy, favourable bacteriological responses occurred in 89.7% and 86.8%, respectively, of dirithromycin- and erythromycin-treated patients. Abdominal pain was the only treatment-emergent event to occur significantly more frequently in dirithromycin-treated patients.
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PMID:Clinical efficacy of dirithromycin in pneumonia. 847 3

Gemifloxacin is a fluoroquinolone antibacterial agent which has an enhanced affinity for topoisomerase i.v.. It has potent activity against most Gram-positive bacteria, particularly Streptococcus pneumoniae. Gemifloxacin is over 30-fold more active than ciprofloxacin and 4- to 8-fold more active than moxifloxacin against this pathogen. Gemifloxacin has excellent activity against Haemophilus influenzae and Moraxella catarrhalis, and is unaffected by beta-lactamase production. It is generally 2-fold less active than ciprofloxacin against most Enterobacteriaceae. Atypical respiratory pathogens (Legionella, Mycoplasma and Chlamydia spp.) are highly susceptible to gemifloxacin. Preliminary results from phase II trials show that oral gemifloxacin 320 mg/day produced bacteriological responses of 94.7% in patients with acute exacerbations of chronic bronchitis and 95% of patients with uncomplicated urinary tract infections. Adverse events included nausea, abdominal pain, headache and mild rash in patients and healthy volunteers treated with gemifloxacin 320 mg/day. Gemifloxacin has a low potential for mild phototoxicity (comparable to that of ciprofloxacin).
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PMID:Gemifloxacin. 1085 45

Gemifloxacin is a dual targeted fluoroquinolone with potent in vitro activity against Gram-positive, -negative and atypical human pathogens--pathogens considered to be important causes of community-acquired respiratory tract infections. Gemifloxacin demonstrates impressive minimal inhibitory concentrations (MIC 90 ) values against clinical isolates of Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Chlamydia pneumoniae and Legionella spp., with MIC 90 values reported to be 0.016-0.06, < 0.0008-0.06, 0.008-0.3, 0.25, 0.125 and 0.016-0.07 microg/ml, respectively. Gemifloxacin is also active in vitro against a broad range of Gram-negative bacilli with MIC 90 values against the Enterobacteriaceae in the range of 0.016 to > 16 microg/ml ( Escherichia coli and Providencia stuartii, respectively), with the majority of the genus having MIC 90 drug concentrations < 0.5 microg/ml. The in vitro activity of gemifloxacin against anaerobic organisms is variable. The MIC values for gemifloxacin are not affected by beta-lactamase production nor by penicillin or macrolide resistance in S. pneumoniae. Gemifloxacin is approved by the FDA to be clinically efficacious against multi-drug resistant S. pneumoniae. The pharmacokinetics of gemifloxacin are such that the drug can be administered orally once-daily to yield or achieve sustainable drug concentrations exceeding the MIC values of clinically important organisms. Gemifloxacin has been shown to target both DNA gyrase (preferred target) and topoisomerase IV (secondary target) - enzymes critical for DNA replication and organism survival - against clinical isolates of S. pneumoniae. This dual targeting activity is thought to be important for reducing the likelihood for selecting for quinolone resistance. Gemifloxacin has been investigated and approved for therapy in patients with community-acquired pneumonia (CAP) and acute exacerbations of chronic bronchitis. In one study, more patients receiving gemifloxacin compared to clarithromycin remained free of exacerbations for longer periods of time (p < 0.016) and gemifloxacin had a shorter time to eradication of H. influenzae than did clarithromycin (p < 0.02). From efficacy studies, gemifloxacin was found to have an adverse profile that was comparable with other compounds. The most frequent side effects were diarrhoea, abdominal pain and headache. Gemifloxacin is a welcomed addition to currently available agents for the treatment of community-acquired lower respiratory tract infections. Other potential indications appear to be within the spectrum of this compound.
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PMID:Gemifloxacin: a new fluoroquinolone. 1515 13

Legionnaires' disease is a common cause of non-zoonotic atypical community-acquired pneumonia (CAP). Legionnaires' disease has varied manifestations but may be diagnosed clinically on the basis of its characteristic pattern of extra-organ involvement. In a patient with non-zoonotic CAP, the clinical and laboratory features in a patient with CAP pointing to the diagnosis of Legionnaires' disease include relative bradycardia, mental confusion/ encephalopathy, loose stools/diarrhea, abdominal pain, mild/transient increases in serum transaminases, decreased serum phosphorous, a highly elevated C-reactive protein (CRP), elevated creatinine phosphokinase (CPK), highly elevated serum ferritin levels, or microscopic hematuria. The radiologic manifestations of Legionnaires' disease are varied and no radiographic appearance is pathopneumonic. Patchy infiltrates in Legionnaires' disease are symmetrical and rapidly progressive even on appropriate anti-Legionella antimicrobial therapy. Spontaneous unilateral pneumothorax is a rare radiographic manifestation of Legionnaires' disease. We present a case of a young male who is presenting clinical finding was that of spontaneous bilateral pneumothoraces due to Legionella CAP. We believe this is the first reported case of Legionnaires' disease presenting as spontaneous bilateral pneumothoraces. Clinicians should be aware of the protean radiological manifestations of Legionnaires' disease. In patients presenting with CAP and unilateral or bilateral spontaneous pneumothorax, clinicians should have Legionnaires' disease in the differential diagnosis.
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PMID:Legionella community-acquired pneumonia (CAP) presenting with spontaneous bilateral pneumothoraces. 1848 36

Spontaneous rupture of the spleen associated with Legionella pneumonia is a rare and life-threatening complication; only three cases have been reported to date. The authors describe a case of a 47-year-old man who presented with pneumonia and abdominal pain. He underwent a splenectomy, and was successfully treated with clarithromycin and levofloxacin.
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PMID:Spontaneous rupture of the spleen associated with Legionella pneumonia. 2188 41


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