Randomized clinical trial on antimicrobial prophylaxis for flexible urethrocystoscopy

OBJECTIVES

One of the main drawbacks of flexible urethrocystoscopy is the risk of urinary tract infection (UTI). In order to reduce this risk, antimicrobial prophylaxis has been considered, however there is not a unanimous view regarding indications, dosage, type of antibiotic, and so on. To clarify this uncertainty, we practiced a pilot and experimental study aimed at assessing the effectiveness of chemoprophylaxis with 3 grams of fosfomycin trometamol in the prevention of UTI after urethrocystoscopy.

METHODS

Sixty patients were entered into a pilot randomized clinical trial between March and August 2011. Thirty patients were assigned to a control group without receiving any antibiotic dose, and the intervention group (30 patients) received 3 g fosfomycin trometamol. Ten days later urine culture and sediment analysis were performed in all patients. Significant bacteriuria was considered from > 105 CFU /ml. One month later a telephone survey was developed to assess urinary symptoms, and assistance to the family doctor. We estimated the cumulative incidence of bacteriuria, pyuria and microhematuria in both groups, and we compared the results using a strategy of analysis per protocol and intention to treat.

RESULTS

The incidence of bacteriuria, pyuria and microhematuria in the control group was 10%, 23.3% and 26.7% respectively and in the intervention groups the values differed depending on the type of analysis. Considering only the 27 patients (per protocol analysis), the incidence would be 11.1%, 37.0% and 29.6% respectively. If we include the three patients who did not completed the study (per intention to treat analysis) and considering their results as negative, the results were 10%, 33.3% and 26.7% respectively. Finally, in the case the three cultures not performed in this group had produced a positive result, the impact would have been 20.0%, 43.3% and 36.7%. In any of the three cases, the differences with the control group were not statistically significant.

CONCLUSIONS

In a selected population and with appropriate aseptic measures, antibiotic chemoprophylaxis does not appear to show a clinically relevant reduction in the incidence of UTI in patients undergoing flexible urethrocystoscopy.

Impact of a region wide antimicrobial stewardship guideline on urinary tract infection prescription patterns

BACKGROUND

Fluoroquinolones are frequently prescribed for non complicated urinary tract infection treatments and have a negative ecological impact. We aimed to substitute them by antibiotics with narrower activity spectrum in order to preserve fluoroquinolone activity in complicated hospital infections.

OBJECTIVE

To assess the impact of a multi-modal approach that combines the dispatching of antibiotic prescription guidelines and voluntary attendance at educational sessions on general practitioners' (GP) antibiotic prescription habits.

SETTING

This study was led in Franche-Comté, a French eastern region, where GPs were given a guideline recommending a restricted use of fluoroquinolones for urinary tract infections.

METHOD

Segmented regression analysis of interrupted time series was used to assess changes in antibiotic prescription.

MAIN OUTCOME MEASURE

The antibiotic prescription data of nitrofurantoin, fosfomycin-trometamol and fluoroquinolones for women aged 15-65 years were obtained from the regional agency of health insurance.

RESULTS

Twenty months after intervention, the number of nitrofurantoin and fosfomycintrometamol prescriptions increased by 36.8% (95% CI: 30.6-42.2) and 28.5% (95% CI: 22.9-35.4), respectively, while that of norfloxacin decreased by 9.1% (95% CI: -15.3 to -3.5).

CONCLUSION

This study suggests that the dispatch of the guideline on urinary tract infection had a moderate impact on antibiotic prescriptions.

Extended-spectrum β-lactamase-producing Enterobacteriaceae: in vitro susceptibility to fosfomycin, nitrofurantoin and tigecycline

OBJECTIVE

To assess the susceptibility trends of community-acquired extended-spectrum β-Iactamase (ESBL)-producing urinary isolates with particular reference to fosfomycin, nitrofurantoin and tigecycline.

MATERIALS AND METHODS

Seven hospitals across the United Arab Emirates participated in this study from June 2008 to March 2010. The antibiotic sensitivity of ESBL-producing uropathogens to a panel of antibiotics including tigecycline, fosfomycin and nitrofurantoin was assessed. The Hyplex ESBL identification system (h-ES-ID) was used for genotypic identification.

RESULTS

Two hundred and ninety-two ESBL-producing Enterobacteriaceae isolates were identified during the study period. Of these, 182 (62%) were urinary isolates and comprised of Escherichia coli: 149 (81.9%), Klebsiella pneumoniae: 30 (16.5%) and Proteus mirabilis: 3 (1.6%). Of the 182 urinary isolates, 179 (98.3%) were from patients with community onset urinary tract infections. The h-ES-ID system identified 172 (94.5%) of the urinary isolates as CTX-M positive. All isolates were susceptible to imipenem and meropenem. Over half of the isolates showed resistance to gentamicin (98; 53.8%), trimethoprim-sulfamethoxazole (139; 76.4%) and ciprofloxacin (143; 78.6%). Sensitivity to nitrofurantoin and fosfomycin was 90 and 100%, respectively. Two CTX-M-positive K. pneumoniae isolates with tigecycline resistance (MIC >4 µg/ml) were identified.

CONCLUSION

There is dissemination of CTX-M ESBL-producing urinary pathogens into the community. Fosfomycin and nitrofurantoin were active against ESBL-positive uropathogens, and emergence of tigecycline resistance needs close monitoring.

Clinical effects of 2 days of treatment by fosfomycin calcium for acute uncomplicated cystitis in women

Fosfomycin calcium is a fosfomycin antimicrobial agent with a characteristic structure. After oral administration, the drug is absorbed and excreted via the kidneys in the unchanged form, without being metabolized in the body. It is, therefore, indicated for the treatment of urinary tract diseases, including cystitis and pyelonephritis. In the present study, the clinical usefulness of fosfomycin calcium (FOSMICIN® TABLETS 500) administered orally at the dosage of 1 g (two tablets) three times daily for 2 days was examined in female patients, who were at least 20 years of age, with acute uncomplicated cystitis of bacterial origin. Of the 48 patients enrolled between February 2008 and August 2008, 39 were evaluable for efficacy and safety. Overall evaluation of the cure revealed that microbiological eradication rate (microbiological outcome) and clinical efficacy rate (clinical outcome) at 5-9 days after drug administration (visit 2) were 94.9%. Determination of the microbiological and clinical outcomes for the evaluation of recurrence at 4-6 weeks after drug administration (visit 3) were 75.8 and 85.7%, respectively. Of the 48 patients, 40 (83.3%) returned to the clinic at visit 3. The causative bacterial species for cystitis was Escherichia coli in 31 (79.5%) of the 39 patients evaluable for efficacy and safety. Adverse drug reactions observed during the administration and follow-up periods included mild diarrhea and loose stools in 1 patient each, neither requiring any specific treatment. Evaluation of cure at visit 2 in patients in whom the causative bacterial species for the infection was E. coli revealed a microbiological outcome of 93.5%, and clinical outcome was 96.8%. Furthermore, evaluation for recurrence at visit 3 revealed a microbiological outcome of 74.1% and clinical outcome of 82.1%. When the patients were divided by age into an under 60 years of age group and an over 60 years of age group, the microbiological and clinical outcomes determined for evaluation of cure at visit 2 were 96.4 and 92.9%, respectively, and the corresponding rates determined for the evaluation of recurrence at visit 3 were 87.0 and 96.0%, respectively, in the under 60 years of age group. In the over 60 years of age group, the corresponding microbiological outcome and clinical outcome rates evaluated for cure were 90.9 and 100%, respectively, and those evaluated for recurrence were 50.0 and 60.0%, respectively. These results indicate the usefulness of fosfomycin calcium administered at 1 g three times daily for 2 days for acute uncomplicated cystitis.

Assessing the emergence of resistance: the absence of biological cost in vivo may compromise fosfomycin treatments for P. aeruginosa infections

BACKGROUND

Fosfomycin is a cell wall inhibitor used efficiently to treat uncomplicated urinary tract and gastrointestinal infections. A very convenient feature of fosfomycin, among others, is that although the expected frequency of resistant mutants is high, the biological cost associated with mutation impedes an effective growth rate, and bacteria cannot offset the obstacles posed by host defenses or compete with sensitive bacteria. Due to the current scarcity of new antibiotics, fosfomycin has been proposed as an alternative treatment for other infections caused by a wide variety of bacteria, particularly Pseudomonas aeruginosa. However, whether fosfomycin resistance in P. aeruginosa provides a fitness cost still remains unknown.

PRINCIPAL FINDINGS

We herein present experimental evidence to show that fosfomycin resistance cannot only emerge easily during treatment, but that it is also cost-free for P. aeruginosa. We also tested if, as has been reported for other species such as Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis, fosfomycin resistant strains are somewhat compromised in their virulence. As concerns colonization, persistence, lung damage, and lethality, we found no differences between the fosfomycin resistant mutant and its sensitive parental strain. The probability of acquisition in vitro of resistance to the combination of fosfomycin with other antibiotics (tobramycin and imipenem) has also been studied. While the combination of fosfomycin with tobramycin makes improbable the emergence of resistance to both antibiotics when administered together, the combination of fosfomycin plus imipenem does not avoid the appearance of mutants resistant to both antibiotics.

CONCLUSIONS

We have reached the conclusion that the use of fosfomycin for P. aeruginosa infections, even in combined therapy, might not be as promising as expected. This study should encourage the scientific community to assess the in vivo cost of resistance for specific antibiotic-bacterial species combinations, and therefore avoid reaching universal conclusions from single model organisms.

[Fosfomycin: past, present and future]

The continuously increasing problem of multidrug-resistant (extended-spectrum beta-lactamase and/or metallo-beta-lactamase producing) bacteria in recent years has created the need to re-evaluate antibiotic therapy for these infections. Fosfomycin is reconsidered to be an alternative treatment agent for such infections. Fosfomycin was first discovered in Spain in 1969 from cultures of Streptomyces species and originally called phosphonomycin. In the early years, fosfomycin was administered parenterally to the patients with many serious infections including meningitis. In some European countries, fosfomycin is occasionally administered for the initial empirical therapy of sepsis or soft-tissue infections. Although in most European countries fosfomycin has been used for many years, it has become available in clinical use only recently in Turkey. In USA, the Food and Drug Administration (FDA) has approved fosfomycin only for the treatment of patients with uncomplicated cystitis. The use of fosfomycin in the treatment of multidrug-resistant bacterial infections and in the treatment of pediatric cancer patients with fever and neutropenia in combination with other antibiotics, has withdrawn attention to this agent. Fosfomycin has a rapid bactericidal effect and a wide antibacterial spectrum, including methicillin-resistant Staphylococcus aureus, glycopeptide-susceptible or resistant enterococci and a large number of gram-negative pathogens. Since it has a long serum half-life and high concentrations are achieved in urine after oral administration; fosfomycin deserved further consideration for single-dose treatment of urinary tract infections caused by Escherichia coil and Enterococcus faecalis. In this review article the properties, mechanisms of action and resistance, antibacterial spectrum, clinical use, toxicity and adverse reactions of fosfomycin have been summarized.

[In vitro activity of fosfomycin trometamol in the treatment of Escherichia coli related uncomplicated urinary tract infections]

Although in certain countries in Europe fosfomycin trometamol (FT) has been used for many years, in Turkey FT has become available in recent years. FT has a broad-spectrum activity against most of gram-positive and gram-negative bacteria. In this study, we aimed to evaluate the effect of FT, a new alternative antimicrobial agent in the treatment of patients with Escherichia coli related uncomplicated lower urinary tract infection (UTI). For this purpose, between May 2007-July 2008, FT susceptibility of 771 nonduplicate E. coli strains, isolated from urine samples of patients with uncomplicated lower UTI (bacteria > or = 10(5) cfu/mL), was determined by disk diffusion method according to Clinical and Laboratory Standarts Institute (CLSI) criteria. Simultaneously, extended-spectrum beta-lactamase (ESBL) detection was performed by double disk synergy test in all isolates. Among all E. coli isolates, FT resistance rate was 0.4% (3/771) and ESBL positivity was 19.5% (150/771). The rates of ESBL producing strains isolated from inpatients and outpatients were 34.1% (70/205) and 14.1% (80/566), respectively, and the difference was found statistically significant (p = 0.0001). Although resistance to FT was not detected in non-ESBL producing E. coli isolates (n = 621), FT resistance rate was 2% (3/150) in ESBL producers. As far as the current literature was concerned this was the largest scale study investigating the activity of FT in Turkey. Resistance to antimicrobials that had been used frequently as therapeutic options for the treatment of E. coli related UTIs, has been increasing. In the present study high susceptibility rates to FT was determined for urinary E. coli isolates. In conclusion, these data suggest that FT may be a good alternative for the treatment of uncomplicated UTIs as a first line antimicrobial agent.

[Application of Monural to treat pregnant women with asymptomatic bacteriuria and acute cystitis]

Asymptomatic bacteriuria (AB) and cystitis affect 4-9% of pregnancies and are associated with pyelonephritis and preterm labor. Screening for AB and adequate antimicrobal therapy prevent most of these serious complications. Twenty- nine pregnant patients, suffering from AB and 9 cases with cystitis were treated with single dose Monura (Fosfomycin trometamol) in a prospective study.

Old antibiotics for infections in critically ill patients

PURPOSE OF REVIEW

The alarming epidemic of multidrug-resistant bacteria and the reluctance of the pharmaceutical industry to invest in the development of new antibiotics have forced clinicians to reintroduce forgotten antibiotics into their practice. This review highlights the effectiveness and safety of older antibiotics when used in the treatment of infections of critically ill patients.

RECENT FINDINGS

Polymyxins emerged as useful antibiotics for the treatment of infections due to multidrug-resistant Gram-negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae. The nephrotoxicity and neurotoxicity associated with their use are less frequent and serious than previously reported. In addition, aerosolized polymyxins may be a useful weapon in the treatment of hospital-acquired pneumonia. Fosfomycin and chloramphenicol have a wide antimicrobial spectrum, are used extensively in Europe and Africa, respectively, and may have an expanded role in our antimicrobial arsenal. Fusidic acid remains active against various staphylococcal strains, while isepamicin (an aminoglycoside used in some European countries) is slightly more effective than amikacin against some Gram-negative bacteria.

SUMMARY

The declining investment of the pharmaceutical industry in the development of new antibiotics and the increasing antimicrobial resistance create a fertile ground for the study and, probably, revival of older antibiotics for use, especially in critically ill patients.

[Lower urinary tract infections: bacterial epidemiology and recommendations]

Lower urinary tract infection remains frequent particularly in women, despite improvement in therapeutic means. It seems likely to revisit bacterial epidemiology and therapeutic available strategies. To analyze elements in presence i.e. infecting bacteria and antibiotics still active or identification of acquired resistance mechanisms should permit to establish the evolution during the last 10 years. The study shows that bacterial epidemiology in urinary tract infection has not changed significantly, despite antibiotic selective pressure expected from overused antibiotics. However few enterobacteriaceae more resistant than Escherichia coli have emerged, but the latter remains predominant. Development of resistance has concerned Negram, amoxicillin and Augmentin, but several active molecules such as ciprofloxacin, Monuril remain available. Duration of treatments are still discussed but there is a tend toward short durations and even mono-doses. The control of lower urinary tract infections remains relatively easy provided that a good therapeutic choice is based on well documented bacteriologic data (infecting species susceptible to the available antibiotics).

[Fosfomycin trometamol: multiple-dose regimen for the treatment of lower urinary tract infections]

INTRODUCTION

A short antibiotic regimen is recommended for the treatment of uncomplicated lower urinary tract infection. Nevertheless, the treatment to follow in other situations is not so clearly defined. When the person affected by lower urinary tract infection is not a young woman, it is recommended to treat at least 7 days, and quinolones or cotrimoxazole are the antibiotics most often used. However, because of the frequency of drug resistance in this type if infection, it is advisable to apply antibiotics with lower rates of resistance, such as fosfomycin trometamol, for longer treatment periods than the often-used single dose.

METHODS

Using the data on urinary elimination of fosfomycin after a single dose obtained in a prior study in healthy volunteers, we simulated the urinary concentrations of this antibiotic following administration of two doses. In addition, we calculated the interval of administration required to achieve urinary concentrations greater than 16 mg/L, the critical concentration of sensitivity for Escherichia coli, one of the most commonly implicated microorganisms in these infections.

RESULTS

Fosfomycin concentrations in urine persisted above the defined cut-off for 161 hours after administration of two 3-g doses of fosfomycin trometamol, 72 hours apart. This implied an efficacy time of 66% in a period of 7 days.

CONCLUSION

From the pharmacokinetic viewpoint, the optimum dosage of fosfomycin trometamol to achieve appropriate urinary concentrations along 7 days is administration of two 3-g doses, 72 hours apart.

Fosfomycin in the treatment of extended spectrum beta-lactamase-producing Escherichia coli-related lower urinary tract infections

Fosfomycin tromethamine (FT) is effective in vitro in extended spectrum beta-lactamase (ESBL)-producing Escherichia coli strains. The aim of this study was to evaluate the effect of FT in the treatment of ESBL-producing E. coli-related lower urinary tract infection. All patients were aged >18; had dysuria or problems with frequency or urgency in passing urine; had >20leukocytes/mm(3) in urine sediment and an ESBL-producing E. coli urine culture (>10(5)cfu/mm(3)); no leukocytosis or fever; and were treated with FT between September 2004 and July 2006 in our outpatient clinic and hospital. ESBL detection was performed by double disk synergy tests. All patients had received FT (3gx1 every other night, three times) and had a control urine culture taken 7 to 9 days after this therapy. Clinical success was defined as resolution of symptoms on the control visit; microbiological success was defined as a sterile control urine culture. In all, 52 patients (aged 55.0+/-18.3, range 19-85; 25 males, 27 females) were included in the study. Overall clinical and microbiological success was 94.3% (49/52) and 78.5% (41/52), respectively. Although it is not a randomized controlled study, these data show that FT may be a suitable, effective and cheap alternative in the treatment of ESBL-producing E. coli-related lower urinary tract infection.

[Fosfomycin, co-trimoxazole and nitrofurantoin in the treatment of recurrent uncomplicated urinary tract infections in type 2 diabetes mellitus]

The aim of this study was to comprise the efficacy of chronic therapy with fosfomycin, co-trimoxazole and nitrofurantoin in the treatment and prevention of recurrent urinary tract infections (UTI) in type 2 diabetic women.

MATERIALS AND METHODS

The study comprised 90 women aged 50-70 years, who suffered from the UTI (isolated bacterial uropathogen sensitive to fosfomycin, co-trimoxazole and nitrofurantoin). Women were divided into 3 groups. Group I comprised patients, who have been treated with fosfomycin, group II with co-tromixazole and group III with nitrofurantoin. Observation period lasted 9 months and for the 6 months patients were treated with antimicrobial agents. Efficacy of antimicrobial treatment was estimated when both clinical cure and bacteriological eradication of uropathogens were achieved.

RESULTS

There were no significant differences in the percentage of patients between study groups, who achieved therapeutic successes after 3 and 6 months of the antimicrobial treatment (NS). Three months after discontinuation of treatment episodes of UTI were observed significantly rarely in group treated with fosfomycin in comparison with the group treated with nitrofurantoin (p = 0.01) and co-trimoxazole (p = 0.02).

CONCLUSION

Fosfomycin, co-trimoxazole and nitrofurantoin are safe and effective antimicrobial methods to cure and prevent UTI. Fosfomycin is associated with rarely recurrence of UTI than nitrofurantoin and co-trimoxazole in the period without its taking.

[Prophylactic effect of fosfomycin on postoperative infection in gastroenterological surgery]

Fosfomycin (FOM), a drug with unique mechanism of action against bacteria, was prospectively compared with cefmetazole (CMZ) and flomoxef (FMOX) to assess its effectiveness in preventing postoperative infections after upper gastroenterological and hepatobiliary surgery. FOM (2g/dose), CMZ (1 g/dose), or FMOX (lg/dose) was infused intravenously 2-3 times daily for basically 4 days including the day of surgery in order to examine whether or not infections would develop after surgery. According to the analysis results of 162 cases, efficacy in preventing infection was 86.8% for FOM, 73.1% for CMZ and 83.3% for FMOX, showing no significant differences among the 3 groups. Thus FOM was considered as efficacious as CMZ or FMOX in prophylaxis against postoperative infections. There were no adverse reactions in the FOM or CMZ group, but 3 cases of adverse reactions occurred in the FMOX group. Based on the above results, the usefulness of FOM for prophylaxis against postoperative infections has been confirmed. At present, the first- and second-generation cephems are most frequently used for prophylaxis against postoperative infections. In order to prevent an increase of resistant strains due to inappropriate use of these drugs, FOM, having no cross resistance with currently used drugs, is a promising candidate for prophylaxis against postoperative infections.