ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04473.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The mechanism by which the fluorinated quinolones produce central nervous system (CNS) effects is currently unknown. We measured the effect of lomefloxacin on cerebral blood flow and metabolism using positron emission tomography. Eighteen healthy, nonsmoking volunteers were randomized to receive lomefloxacin 400 mg, ciprofloxacin 750 mg, or placebo given in a single‐blind fashion every 12 hours for 72 hours, the time window for maximum lomefloxacin CNS effects. Subjects receiving lomefloxacin had a mean (± SEM) cerebral blood flow (CBF) of 46 (2.9) ml/min/100 g, glucose metabolism (FDG) 4.7 (0.4) mg/min/100 g, oxygen metabolism (OM) 3.3 (0.3) ml/min/100 g, and oxygen extraction (%OM) 0.4 (0.04). Posttreatment values were 43 (3.6) ml/min/100 g, 4.2 (0.4) mg/min/100 g, 2.6 (0.3) ml/min/100 g, and 0.4 (0.03), respectively. Values for subjects receiving ciprofloxacin were CBF 44.8 (1.6) ml/min/100 g, FDG 4.9 (0.7) mg/min/100 g, OM 4.1 (0.4) ml/min/100 g, and %OM 0.6 (0.03) at baseline, and 40.3 (3.5), 4.5 (0.6), 3.4 (0.4), and 0.5 (0.09), respectively, after treatment. For placebo‐treated subjects, baseline values were CBF 41.4 (1.9) ml/min/100 g, FDG 4.9 (0.5) mg/min/100 g, OM 3.3 (0.4) ml/min/100 g, and %OM 0.5 (0.07), and respective posttreatment values were 42.1 (2.3), 5.0 (0.6), 3.5 (0.3), and 0.5 (0.02). No effect was observed on visual (qualitative), blinded reading of the scans. No significant effect on cerebral blood flow or metabolism was detected. We conclude that short‐term administration of lomefloxacin or ciprofloxacin to healthy volunteers does not have a significant effect on cerebral blood flow, or on oxygen or glucose metabolism. Trends toward decreased metabolism in the quinolone‐treated subjects are consistent with findings from other published trials, although their significance is

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04474.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

This pilot study was undertaken to characterize age‐related alterations in airway and metabolic β2‐adrenergic receptor response using terbutaline as a probe. A single dose of terbutaline 0.007 mg/kg was administered subcutaneously to 10 young (range 20–35 yrs) and 10 elderly (range 60–73 yrs) men and women with asthma. β‐Receptor function was assessed by serial pulmonary function tests, heart rate, blood pressure, plasma potassium, glucose, insulin, and catecholamine levels, and in vitro 3′, 5′‐cyclic adenosine monophosphate (cAMP) production of pure T lymphocytes. The trend was for lung β2‐receptor response (bronchodilation) and T lymphocyte cAMP production to be lower in elderly than in young asthmatics, but differences did not reach statistical significance. Elderly subjects' β1‐adrenergic receptor responsiveness (systolic blood pressure) was also dampened. These data suggest that T lymphocyte stimulation does reflect pulmonary β2‐receptor response. Whether elderly asthmatics require and tolerate higher dosages of parenteral terbutaline than younger asthmat

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04475.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Several reports have been published on the disposition of methotrexate (MTX) when given in low dosages, but none in asthmatic patients. To address this matter, pharmacokinetic studies were performed in nine patients with severe, steroid‐requiring asthma (ages 18–76 yrs) after the sixth weekly intramuscular dose of MTX. Theophylline pharmacokinetic studies were also performed at baseline prior to the start of MTX treatment and at the time of the MTX studies. Total systemic clearance of MTX, given as mean (SD), was 122.6 (25.1) ml/minute, volume of distribution at steady state 0.49 (0.2) L/kg, half‐life 3.1 (0.3) hours, mean residence time 5.0 (0.6) hours, and renal clearance 89.1 (36.3) ml/minute. These values are similar to those previously reported for other patient populations receiving low‐dose MTX. Eight of these patients were evaluated for changes in theophylline pharmacokinetics. Theophylline clearance at week 6 decreased an average of 19% from baseline and correlated inversely with total MTX clearance. Percentage change in theophylline clearance from baseline was inversely correlated with MTX nonrenal clearance, but was not statistically significant. This finding may indicate competition for clearance pathways between MTX and theop

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04476.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Great advances have been made in the last two decades in understanding mechanisms of antibiotic resistance among pathogenic bacteria.1From the clinician's perspective, the value of this scientific information at the bedside is not always obvious. Its importance can be emphasized by exploring two separate avenues: anecdotal reports illustrating the clinical cases in which one often sees resistance, and reports to the Centers for Disease Control (CDC) and some relevant findings from the results of a recent multicenter study ofEnterobacterbacteremia.

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04477.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

The clinical and economic impacts of bacterial resistance are substantial. The development of bacterial resistance during a course of therapy often leads to clinical failure, prolonged hospitalization, increased morbidity, mortality, and increased health care costs. Resistance has been reported to occur most frequently with aminoglycosides, quinolones, and β‐lactam antimicrobials, and often occurs during the course of treatment of gram‐negative bacillary infection. Resistance is most commonly due to enzymatic inactivation, permeability changes, or receptor mutation. Strategies for the prevention of resistance include appropriate infection‐control practices, judicious use of antimicrobials, enhancement of host defenses, and the use of antimicrobial combinations. Despite success in vitro and in experimental animal models of infection, clinical trials in humans of antimicrobial combinations for the prevention of resistance have yielded mixed results. Use of the most potent agents available, preferably in bactericidal synergistic combinations, may be effective in preventing in vivo emergence of bacterial resi

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04478.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Single doses of nonprescription analgesics are commonly used to treat self‐diagnosed conditions. To evaluate the safety of single doses of nonprescriptionstrength ibuprofen, we examined reported side effects from 15 double‐blind, randomized, controlled trials we conducted of the drug to treat various common painful conditions (e.g., headache, sore throat). All studies included placebo and another nonprescription analgesic, acetaminophen. A total of 878 subjects received ibuprofen 200 or 400 mg, 849 acetaminophen 650 or 1000 mg, and 852 placebo. The overall frequency of side effects was comparable: ibuprofen 2.4%, acetaminophen 3.2%, and placebo 2.1%. The frequency of central nervous system symptoms was 0.8%, 2.1%, and 0.9%, respectively. Upper gastrointestinal upset ranged from 0.8–0.9% of subjects in all groups. We conclude that single doses of nonprescription ibuprofen are well tolerated and demonstrate a side effect profile indistinguishable from that of acetaminophen and pl

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04479.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Moricizine, a recently approved phenothiazine antiarrhythmic agent, is reported to be associated with a low frequency of congestive heart failure. A 61‐year‐old man with a history of congestive heart failure and ischemic heart disease began taking moricizine 250 mg every 8 hours to suppress his monomorphic sustained ventricular tachycardia. After five doses he became progressively short of breath and was in pulmonary edema. Moricizine was discontinued, intravenous diuretics were administered, and the patient's clinical status stabilized. Twelve hours later, however, he developed polymorphic ventricular tachycardia and was not successfully resuscitated. Despite claims as to its safety, limited data strongly suggest that moricizine, like other antiarrhythmics, may be detrimental in patients with preexisting ventricular dysfunction, and should be prescribed with caut

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04480.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

A 32‐year‐old man diagnosed with acquired immunodeficiency syndrome and a disseminated cytomegalovirus infection experienced seizures associated with the administration of ganciclovir. Seizures began 1 month after initiation of therapy and worsened with increasing dosages. Despite phenytoin administration, the seizure‐like activity subsided only after discontinuing ganciclovir. After rechallenge with ganciclovir the seizures recurred. Although this case was confounded by numerous patient and disease factors, the Naranjo algorithm produced a score of 7, indicating a probable association between ganciclovir and seizure act

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04481.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

Theophylline and mexiletine can be prescribed in patients with chronic obstructive pulmonary disease with coexistent arrhythmias. The drugs have common metabolic pathways that may result in an interaction. A patient who was taking theophylline became toxic after the initiation of mexiletine. Discontinuation of mexiletine led to an improvement in theophylline clearance.

ISSN:0277-0008    

DOI:10.1002/j.1875-9114.1992.tb04482.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY