Antibiotic drug prescription in respiratory tract infections: a pharmacoepidemiological survey among general practitioners in a region of Italy

The spectrum of Cefditoren for Lower Respiratory Tract Infections (LRTIs) in Surabaya

Background:

Empirical antibiotics among outpatients with Lower Respiratory Tract Infections (LRTIs) are scarcely allocated in Indonesia. The study aims to evaluate the pathogens causing LRTIs, drug sensitivity test and the minimum inhibitory concentrations of 90% (MIC90) of Cefditoren, Azithromycin, Amoxicillin-Clavulanic Acid, and Cefixime

Methods:

The study was performed in adult outpatients with LRTI that can be expectorated. Patients with diabetes mellitus, HIV, lung tuberculosis, renal or hepatic failure, and hemoptysis were excluded. We performed bacterial culture, antibiotic sensitivity, and MIC measurement of four antibiotics.

Results:

There were 126 patients with LRTIs, and 61 patients were eligible for the study. We identified 69 bacteria. We found Klebsiella pneumonia (n=16; 26.23%), Staphylococcus aureus (n=11; 18%), Pseudomonas aeruginosa (n=8; 13.11%), Acinetobacter baumanii complex (n= 4; 6.55%), Streptococcus pneumonia (n=3; 4.9%) and others bacteria as causa of LRTI. Testing MIC90 of Cefditoren and three empiric antibiotics on LRTI found that Cefditoren has a lower MIC of 90 for K. pneumonia (0.97(2.04) µg.mL-1) and S. pneumonia (0.06(0.00)µg.mL-1) than other antibiotics, but almost the same as Cefixime ((0.05(0.16)µg.mL-1) and (0.38(0.17)µg.mL-1). MIC90 Cefditoren for S.aureus (3.18(3.54)µg.mL-1) and P.aeruginosa (9.2(3.53)µg.mL-1) is lower than Cefixime but higher than Azithromycin and Amoxicillin-Clavulanic acid. Reference data MIC90 of Cefditoren for LRTI bacteria is lower than the other three oral empirical antibiotics.

Conclusions:

In vitro studies of an outpatient LRTI in Surabaya found gram-negative bacteria dominant. Cefditoren can inhibit K.pneumonia and S.pneumonia has lower MIC90 compared to other antibiotics. Cefditoren can inhibit gram-negative and positive bacteria causing LRTI.

What rationale do GPs use to choose a particular antibiotic for a specific clinical situation?

Background

Many studies have investigated the ways in which physicians decide whether to prescribe antibiotics, but very few studies have focused on the reasons for which general practitioners (GPs) choose to prescribe a particular antibiotic in a specific clinical situation. Improvements in our understanding of the rationale behind GPs’ decisions would provide insight into the reasons for which GPs do not always prescribe the antibiotic recommended in clinical practice guidelines and facilitate the development of appropriate interventions to improve antibiotic prescription.

The objective of the study was to understand the rationale used by GPs to decide which antibiotic to prescribe in a specific clinical situation, and to propose a model representing this rationale.

Methods

We used a three-step process. First, data were collected from interviews with 20 GPs, and analysed according to the grounded theory approach. Second, data were collected from publications exploring the factors used by GPs to choose an antibiotic. Third, data were used to develop a comprehensive model of the rationale used by GPs to decide which antibiotic to prescribe.

Results

The GPs considered various factors when choosing antibiotics: factors relating to microbiology (bacterial resistance), pharmacology (adverse effects, efficacy, practicality of the administration protocol, antibiotic class, drug cost), clinical conditions (patient profile and comorbid conditions, symptoms, progression of infection, history of antibiotic treatment, preference), and personal factors (GP’s experience, knowledge, emotion, preference).

Conclusions

Various interventions, targeting all the factors underlying antibiotic choice, are required to improve antibiotic prescription. GP-related factors could be improved through interventions aiming to improve the GPs’ knowledge of antibiotics (e.g. continuing medical education). Factors relating to microbiology, pharmacology and clinical conditions could be targeted through the use of clinical decision support systems in everyday clinical practice.

Prevalence of antimicrobial resistance in Streptococcus pneumoniae circulating in Italy: results of the Italian Epidemiological Observatory Survey (1997-1999)

The Italian Epidemiological Observatory (IEO), a surveillance program supported by the SmithKline Foundation, analyzed the susceptibility of 2,664 community-acquired respiratory Streptococcus pneumoniae derived from over 50 clinical microbiology laboratories during 1997-1999, against 21 antibiotics adopting a quantitative methodology. Throughout these years, total penicillin resistance varied from 14.3% to 10.2%. High-level resistance has remained stable, ranging from 3.8% to 4.1%, while a decrease in low-level resistance (from 10.3% to 6.1%) has been recorded. Lack of susceptibility to macrolides ranged from 29.1% in 1997 to 25.5% in 1999. Similar figures have also been observed with tetracycline and co-trimoxazole (rates of resistance around 30%). As expected, large geographical variations in resistance rates were found for all drugs. Amoxicillin and amoxicillin-clavulanate were 100% active on penicillin-intermediate isolates. Injectable third-generation cephalosporins and carbapenems were also capable of inhibiting a large proportion of these microorganisms. Rifampin was the most potent non-beta-lactam compound tested. In contrast to the situation prevailing elsewhere, in Italian children (aged 0-5 years) presenting with respiratory conditions, the total rate of penicillin resistance (3%) was lower than that shown by the adult population (10.9%). However, lack of susceptibility to macrolides, tetracycline, and cotrimoxazole (35%, 41%, 44%) was more incident in pediatric than in adult patients (25%, 26%, 28% respectively). Strains recovered from blood in 1999 (67) were much more susceptible to penicillin (98.5%) than respiratory pneumococci (89.8%), whereas macrolides, tetracycline, and cotrimoxazole were consistently less active (75%, 67%, 64%).