Israel Medical Association Journal

Objectives: To test the in vitro activity of linezolid (oxazolidinone) and other antimicrobial agents against MRSA[1] isolates recovered from hospitalized patients.

Methods: We tested 150 MRSA isolates recovered from hospitalized patients. The minimal inhibitory concentration of vancomycin, teicoplanin, pristinamycin (quinupristin-dalforistin), and linezolid was determined by the Etest method. Susceptibility to other antibiotics was tested by the disk diffusion method.

Results: All isolates were sensitive to vancomycin, teicoplanin, pristinamycin, and linezolid. The MIC₉₀ was 2.0 mg/ml for vancomycin and teicoplanin (range 0.5–2.0 mg/ml and 0.125–2.0 mg/ml, respectively), and 0.5 mg/ml for pristinamycin and linezolid (range 0.125–0.75 mg/ml and 0.125–0.5 mg/m, respectively). Of the other antibiotics, fusidic acid showed the best in vitro activity, with 96.7% susceptibility, associated with trimethoprim/sulfamethoxazole (85.8%) and minocycline (84%). Penicillin was associated with the lowest susceptibility (1.3%), associated with ofloxacin (3%) and erythromycin (14%). An increase in the minimal inhibitory concentration value of vancomycin was associated with a significant decrease in resistance to TMP-SMZ[2] (P < 0.01) and an apparent increase in resistance to other antibiotics.

Conclusion: The excellent in vitro activity of linezolid and its reported in vivo effectiveness renders it an important therapeutic alternative to vancomycin in the treatment of MRSA infection.

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[1] MRSA = methicillin-resistant Staphylococcus aureus

[2] TMP-SMX = trimethoprim/sulfamethoxazole

The complexity of medical problems is a well-recognized phenomenon. In the presence of economic and cultural restrictions, medical decision-making can be particularly challenging. This paper outlines a system of analysis and decision-making for solving such problems, and briefly describes a case study in which the method was used to analyze the case of antibiotic overprescribing in a large health maintenance organization. The purpose of the study was to determine if a technique for problem-solving in the field of engineering could be applied to the complex problems facing primary care. The method is designated Systematic Inventive Thinking and consists of a three-step procedure: problem reformulation, general search-strategy selection, and an application of idea-provoking techniques. The problem examined is the over-prescribing of antibiotics by general practitioners working in Maccabi Healthcare Services, an HMO[1] serving one and a half million patients in Israel. The group of healthcare professionals involved in the discussions generated 117 ideas for improving antibiotic use. Six of these ideas were then implemented in a national campaign in the winter of 2000/1 and 2001/2. During this period, a significant reduction in per-visit antibiotic purchasing was observed for influenza visits (from 79.2 per 1,000 to 58.1 per 1,000, P < .0001), but not for other categories of visits. The SIT[2] methodology is a useful technique for problem-solving and idea generation within the medical framework.

Background: Erysipelas is a skin infection generally caused by group A streptococci. Although penicillin is the drug of choice, some physicians tend to treat erysipelas with antibiotics other than penicillin.

Objectives: To define the pattern of antibiotic use, factors affecting antibiotic selection, and outcome of patients treated with penicillin versus those treated with other antimicrobial agents.

Methods: A retrospective review of charts of adult patients with discharge diagnosis of erysipelas was conducted for the years 1993-1996.

Results: The study group comprised 365 patients (median age 67 years). In 76% of the cases infection involved the leg/s. Predisposing condition/s were present in 82% of cases. Microorganisms were isolated from blood cultures in only 6 of 176 cases (3%), and Streptococcus spp. was recovered in four of these six patients. Cultures from skin specimens were positive in 3 of 23 cases. Penicillin alone was given to 164 patients (45%). Other antibiotics were more commonly used in the second half of the study period (P < 0.0001) in patients with underlying conditions (P = 0.06) and in those hospitalized in the dermatology ward (P< 0.0001). Hospitalization was significantly shorter in the penicillin group (P= 0.004). There were no in-hospital deaths.

Conclusions: We found no advantage in using antibiotics other than penicillin for treating erysipelas. The low yield of skin and blood cultures and their marginal impact on manage­ment, as well as the excellent outcome suggest that this infection can probably be treated empirically on an outpatient basis.
 

Background: Current treatment for the eradication of Helicobacter pylori in patients with peptic disease is based on the combination of antibiotic and anti-acid regimens. Multiple combinations have been investigated, however no consensus has been reached regarding the optimal duration and medica­tions.

Objectives: To assess the efficacy of two treatment regimens in patients with peptic ulcer disease and non-ulcer dyspepsia, and to determine the need for gastric mucosal culture in patients failing previous treatment.

Methods: Ninety patients with established peptic ulcer and NUD (with previously proven ulcer) were randomly assigned to receive either bismuth-subcitrate, amoxycillin and metrnida­zole (8AM) or lansoprasole, clarithromycine and metronida­zole (LCM) for 7 days. Patients with active peptic disease were treated with ranitidine 300 mg/day for an additional month.

Results: Eradication failed in 8 of the 42 patients in the 8AM group and in 2 of the 43 patients in the LCM group, as determined by the ¹³C urea breath test or rapid urease test (19% vs. 5%, respectively, P=0.05). Five of these 10 patients were randomly assigned to treatment with lansoprazole, amoxycillin and clarithromycin (LAC) regardless of the culture obtained, and the other 5 patients were assigned to treatment with lansoprazole and two antibacterial agents chosen according to a susceptibility test. Eradication of H. pylon was confirmed by the ‘³C urea breath test. The same protocol (LAC) was used in all patients in the first group and in four of the five patients in the second group. The culture results did not influence the treatment protocol employed.

Conclusions: Combination therapy based on proton pump inhibitor and two antibiotics is superior to bismuth-based therapy for one week. Gastric-mucosal culture testing for sensitivity of H. pylon to antibiotics is probably unnecessary before the initiation of therapy for patients with eradication failure.

Background: Cefuroxime is a second-generation cephalosporin antibiotic used widely for the treatment of various infections.

Objectives: To assess the appropriateness of cefuroxime usage as well as the long-term impact of re-feeding the results to prescribing physicians.

Methods: Drug utilization evaluation involved three data-collecting periods, each comprising 6 weeks, during which all patients receiving cefuroxime were evaluated. Results of phase I were distributed to all physicians in a newsletter and departmental lectures; phase II was announced and conducted 6 months later. An identical phase III was unannounced and conducted one year after phase II. The study included all patients receiving cefuroxime during the three phases. The main outcome measure was appropriateness of initiation, and continuation beyond 3 days, of empirical treatment. Appropriateness was determined according to a prepared list of indications based on the literature and the hospital's protocols.

Results: Cefuroxime was initiated appropriately in 104 of 134 patients (78%) in phase I, in 85 of 100 (85%) in phase II, and in 93 of 100 (93%) in phase III (P<0.001). Cefuroxime was continued appropriately after 3 days in 58/134 (43%), 57/100 (57%) and 70/100 (70%) respectively (P<0.001). The total number of appropriate treatment days out of all treatment days increased from 516 of 635 (81%) in phase I, to 450 of 510 (88%) in phase II, to 485 of 509 (95%) in phase III (P<0.001). The principal reason for cefuroxime usage was community-acquired respiratory tract infection.

Conclusion: Drug utilization evaluation may provide valuable data on the usage of a particular drug. This information, once re-fed to physicians, may improve utilization of the particular drug. This positive effect may be prolonged beyond the immediate period of observation.