Potential Drug-Drug Interactions with Antimicrobials in Hospitalized Patients: A Multicenter Point-Prevalence Study.

BACKGROUND Improper use of antimicrobials can cause adverse drug events and high costs. The purpose of this study was to investigate the frequency and potential drug-drug interactions associated with antimicrobials among hospitalized patients. MATERIAL AND METHODS This study was conducted on the same day in 5 different hospitals in Turkey. We included patients aged ³18 years who received at least 1 antimicrobial drug and at least 1 of any other drug. The Micromedex® online drug reference system was used to control and describe the interactions. Drug interactions were classified as contraindicated, major, moderate, and minor. RESULTS Potential drug-drug interactions with antimicrobials were 26.4% of all interactions. Five (42%) of 12 contraindicated interactions and 61 (38%) of 159 major interactions were with antimicrobials. Quinolones, triazoles, metronidazole, linezolid, and clarithromycin accounted for 173 (25.7%) of 673 prescribed antimicrobials, but were responsible for 141 (92.1%) of 153 interactions. In multivariate analysis, number of prescribed antimicrobials (odds ratio: 2.3001, 95% CI: 1.6237-3.2582), number of prescribed drugs (odds ratio: 1.2008, 95% CI: 1.0943-1.3177), and hospitalization in the university hospital (odds ratio: 1.7798, 95% CI: 1.0035-3.1564) were independent risk factors for developing drug interactions. CONCLUSIONS Due to risk of drug interactions, physicians should be more cautious when prescribing antimicrobials, particularly when prescribing quinolones, linezolid, azoles, metronidazole, and macrolides.

Hydrocephalus and vasculitis delay therapeutic responses in tuberculous meninigitis: Results of Haydarpasa-III study.

AIMS: There is no report on the factors affecting the resolution of symptoms related to meningitis during treatment of tuberculous meningitis (TBM). Thus, we examined the factors associated with early therapeutic responses. MATERIALS AND METHODS: This multicenter study included 507 patients with microbiologically confirmed TBM. However, 94 patients eligible for the analysis were included in this study from 24 centers. Six out of 94 patients died and the statistical analysis was performed with 88 survivors. Early and late responder groups were compared in the statistical analysis. P < 0.05 were considered to show a significant difference. RESULTS: In the multivariate analysis, the presence of vasculitis (P = 0.029, OR = 10.491 [95% CI, 1.27-86.83]) was found to be significantly associated with a delayed fever response whereas hydrocephalus was associated with altered mental status for >9 days duration (P = 0.005, OR = 5.740 [95% CI, 1.68-19.57]). According to linear regression analysis, fever was significantly persisting (>7 days) in the presence of vasculitis (17.5 vs. 7, P< 0.001) and hydrocephalus (11 vs. 7, P = 0.029). Hydrocephalus was significantly associated with persisting headache (21 vs. 12, P = 0.025), delayed recovery of consciousness (19.5 vs. 7, P = 0.001), and a delay in complete recovery (21 vs. 14, P = 0.007) in the linear regression analysis. Following institution of treatment, the complaints seemed to disappear in up to 2 weeks among TBM survivors. CONCLUSIONS: In the absence of hydrocephalus or vasculitis, one week of anti-tuberculosis treatment seems to be adequate for the resolution of TBM symptoms. Hydrocephalus and vasculitis delay the resolution of TBM symptoms in response to antimycobacterial treatment.

Investigation of the antibiotic susceptibility patterns of pathogens causing nosocomial infections.

OBJECTIVE: The aim of this study is to determine the resistance patterns of bacteria causing nosocomial infections. The outcome of this resistance was followed for 3 years. METHODS: This study was carried out during 2000 to 2002 at a university hospital in Turkey. The resistance patterns of 570 bacteria (390 Gram-negative, 180 Gram-positive) against meropenem, imipenem, ceftazidime, cefotaxime, cefepime, piperacillin/tazobactam, ciprofloxacin and tobramycin were investigated using the E-test. Extended-spectrum beta-lactamase (ESBL) production was determined using ceftazidime and ceftazidime/clavulanic acid E-test strips. RESULTS: Meropenem was the most effective antibiotic against Gram-negative organisms (89.0%); this was followed by imipenem (87.2%) and piperacillin/tazobactam (66.4%). The most active antibiotic against Gram-positive bacteria was imipenem (87.2%) and this was followed by piperacillin/tazobactam (81.7%) and meropenem (77.8%). The rates of production of ESBL by Escherichia coli were 20.9%, Klebsiella pneumoniae 50% and Serratia marcescens were 46.7%. Extended-spectrum beta-lactamase production increased each year (21.7%, 22.1% and 45.5%). All of the ESBL producing isolates were sensitive to meropenem and 98.5% sensitive to imipenem. AmpC beta-lactamase was produced by 20.9% of the Enterobacter species spp, Citrobacter spp. and Serratia marcescens. All of these were sensitive to meropenem and 77.8% to imipenem and ciprofloxacin. Multi-drug resistance rates in Acinetobacter spp were 45.4% and 37.7% in Pseudomonas aeruginosa isolates. CONCLUSION: As in the entire world, resistance to antibiotics is a serious problem in our country. Solving of this problem depends primarily on prevention of the development of resistance.

Efficacy of rifampicin plus doxycycline versus rifampicin plus quinolone in the treatment of brucellosis.

OBJECTIVE: The aim of this study was to compare the efficacy, tolerability and side effects of 2 treatment regimens for brucellosis. METHODS: Fifty-seven patients with brucellosis were followed up in our clinic. The patients were given rifampicin plus doxycycline or rifampicin plus quinolone. Thirty patients (group one) received rifampicin 600mg/daily plus doxycycline 100mg twice daily and 27 patients (group 2) received quinolones (ofloxacin 200mg twice daily peroral) plus rifampicin 600mg/daily. Both regimens were administered for 45-days. During the course of treatment, patients were followed for the disappearance of physical signs and symptoms. All patients were followed up at least 6-months after cessation of therapy. Diagnosis of brucellosis was established by utilizing the following criteria; Isolation of brucella species in blood, body fluids (Sceptor, Becton-Dickinson, United States of America), compatible clinical picture supported by the detection of specific antibodies at significant titers or demonstration, or both, of an at least 4 fold rise in antibody titer in serum specimens taken after 2-weeks. Significant titer was determined to be >one/160 in the standart tube agglutination test (Brucella abortus Cromatest, Linear Chemicals, Spain). RESULTS: Of patients 14 (24.5%) were male and 43 (75.5%) were female. Mean age was 36.8 11.3 years (range 15-65). Sacroiliitis was the most common involvement in both groups 9 (30%) versus 6 (22%), followed by peripheral arthritis 6 (20%) versus 6 (22%). In this study, relapse rate was found 7.2% and 6.7% for ofloxacin plus rifampicin and doxycycline plus rifampicin for a 6-week therapy (p>0.05). No significant adverse effects were associated with either combination. CONCLUSION: These results indicated that a 45-day course of doxycycline plus ofloxacin combination was as effective as the doxycycline plus rifampicin combination in patients with brucellosis.