Changes in renal function after changes in antifungal drug therapy.
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Adult↗
Biomedical subjects
Ralph H Raasch
Publications and source records attributed to Ralph H Raasch.
Anidulafungin: review of a new echinocandin antifungal agent.
Anidulafungin (Vicuron Pharmaceuticals) is a new echinocandin antifungal with potent activity against Aspergillus and Candida spp. Anidulafungin is a noncompetitive inhibitor of (1,3)-beta-D-glucan synthase within fungal cells. The drug is rapidly distributed and steady-state concentrations are achieved after the first dose, when a loading dose of twice the daily maintenance dose is given on day 1. Drug biotransformation occurs via chemical degradation, with no hepatic metabolism or renal elimination. A favorable pharmacokinetic profile and lack of significant drug interactions suggest that patients can receive anidulafungin without dosage adjustments. These characteristics, in addition to comparable efficacy to fluconazole (Diflucan, Pfizer Ltd) in the treatment of esophageal candidiasis, support further investigation of its use in the treatment of systemic fungal infections caused by Candida and Aspergillus spp.
Anidulafungin↗
Single versus combined antibiotic therapy for gram-negative infections.
OBJECTIVE: To evaluate the available clinical data regarding single versus combination antimicrobial therapy for treatment of gram-negative infections, focusing on the more recent data in predominantly nonneutropenic hosts. In vitro and in vivo data regarding various antimicrobial combinations are also discussed. DATA SOURCES: Clinical trials, review articles, and meta-analyses were identified from a MEDLINE search (1960-July 2003). Special attention was given to clinical outcome trials performed since 1989. Search terms included gram-negative infections, drug synergism, Pseudomonas aeruginosa, monotherapy, combination therapy, carbapenems, beta-lactams, cefepime, aminoglycosides, and fluoroquinolones. DATA SYNTHESIS: Although most of the studies were not randomized, double-blind, or controlled, the most recent literature indicates that monotherapy with agents that are active against isolated organisms, including P. aeruginosa, may be appropriate for most patients. Efficacy outcomes, including mortality, did not significantly differ in most studies comparing single and combination therapies. Some trials suggest that combination therapy may be preferred in neutropenic patients and those with pseudomonal infections. CONCLUSIONS: Hospitalized patients with gram-negative infections are often treated with combination antimicrobial agents; however, some of the recently available data, although limited, suggest that administration of monotherapy is a feasible alternative in certain patient populations.
Animals↗
In vitro assessment of urinary isolates of ampicillin-resistant enterococci.
OBJECTIVE: Susceptibility and minimum inhibitory concentration (MIC) studies of ampicillin-resistant enterococci (ARE) were performed with vancomycin, ciprofloxacin, and trovafloxacin. Ampicillin MICs were determined to make comparisons with achievable urinary concentrations of ampicillin. DESIGN: From July 1998 to April 1999, all enterococci isolated from urinary specimens were tested for susceptibility to ampicillin by disk diffusion. For all ARE, vancomycin, ciprofloxacin, and trovafloxacin susceptibilities were determined by use of either disk diffusion or the E-test. Ampicillin MICs were determined for these isolates by liquid agar microdilution testing. ARE were identified to the species level on the basis of biochemical reactions. SETTING: The study was performed at a university-affiliated tertiary care hospital. OUTCOME MEASURES: In vitro susceptibility studies and MIC determinations were performed in accordance with the National Committee for Clinical Laboratory Standards. RESULTS: A total of 310 urine samples were culture positive for enterococcus. Thirty (9.7%) unduplicated isolates were resistant to ampicillin. Of these, nine ARE isolates (30%) were also vancomycin resistant, whereas only 2 ampicillin-susceptible isolates were vancomycin resistant (p < 0.05). All ARE were resistant to ciprofloxacin, and 29 (96.7%) were resistant to trovafloxacin. Nine (30%), 18 (60%), and 3 (10%) isolates had an ampicillin MIC of 128, 256, and 512 micrograms/mL, respectively. Ampicillin MICs did not differ significantly between vancomycin-susceptible and -resistant isolates (p = 0.963). Twenty-seven isolates (90%) were identified as Enterococcus faecium; the other 3 were either Enterococcus avium or Enterococcus raffinosus. CONCLUSIONS: Ampicillin resistance is associated with resistance to vancomycin. Most ARE are resistant to fluoroquinolone antibiotics such as ciprofloxacin and trovafloxacin. Ampicillin MICs for ARE found in these urinary specimens were all within 1 dilution of 256 micrograms/mL, a concentration achievable in the urine with higher doses of oral amoxicillin or intravenous ampicillin. Additional studies are needed to assess the clinical implications of these data.
Adult↗
Treatment of tick-borne diseases.
OBJECTIVE: To review the data regarding the pharmacotherapy of Lyme disease, Rocky Mountain spotted fever (RMSF), and the human ehrlichioses. DATA SOURCES: English-language literature was identified via MEDLINE (1966-January 2002) using the keywords Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis. Textbooks and other pertinent resources were also reviewed. STUDY SELECTION AND DATA EXTRACTION: All articles identified through the data sources above were evaluated and reviewed if pertinent to the objective. DATA SYNTHESIS: Tick-borne diseases are the most common vector-transmitted diseases in North America. Each disease causes significant morbidity and, in the case of RMSF, mortality if patients go untreated. If the disease syndromes are recognized early and treatment is initiated, complications are greatly reduced. Doxycycline is active against each of the causative organisms, simplifying empiric treatment. CONCLUSIONS: Effective pharmacotherapy exists to treat each of these diseases, assuming diagnosis is made quickly. The beta-lactam and tetracycline antibiotics appear to be the most effective therapy for Lyme disease. The tetracyclines, but not the beta-lactams, are effective for RMSF and the human ehrlichioses. Since Borrelia burgdorferi and the human granulocytic ehrlichiosis agent are becoming more common coinfecting pathogens, tetracycline or doxycycline should be considered the drugs of choice for patients from endemic areas where exposure to both pathogens may have occurred. Doxycycline is the preferred agent because of decreased frequency of administration and adverse effects.
Anti-Infective Agents↗