Clinical use of fluoroquinolones in children

A short review of human exposure to antibiotics based on urinary biomonitoring

Antibiotics play a role in preventing and treating infectious diseases and also contribute to other health risks for humans. With the overuse of antibiotics, they are widely distributed in the environment. Long-term exposure to multiple antibiotics may occur in humans through medication and dietary intake. Therefore, it is critical to estimate daily intake and health risk of antibiotics based on urinary biomonitoring. This review compares the strengths and weaknesses of current analytical methods to determine antibiotics in urine samples, discusses the urinary concentration profiles and hazard quotients of individual antibiotics, and overviews correlations of antibiotic exposure with the risk of diseases. Liquid chromatography-tandem mass spectrometry is most applied to simultaneously determine multiple types of antibiotics at trace levels. Solid-phase extraction with a hydrophilic-lipophilic balance adsorbent is commonly used to extract antibiotics in urine samples. Fifteen major antibiotics with relatively higher detection frequencies and concentrations include sulfaclozine, trimethoprim, erythromycin, azithromycin, penicillin V, amoxicillin, oxytetracycline, chlortetracycline, tetracycline, doxycycline, ofloxacin, enrofloxacin, ciprofloxacin, norfloxacin, and florfenicol. Humans can be easily at microbiological effect-based risk induced by florfenicol, ciprofloxacin, azithromycin, and amoxicillin. Positive associations were observed between specific antibiotic exposure and obesity, allergic diseases, and mental disorders. Overall, the accessible, automated, and environmentally friendly methods are prospected for simultaneous determinations of antibiotics at trace level in urine. To estimate human exposure to antibiotics more accurately, knowledge gaps need to be filled up, including the transformation between parent and metabolic antibiotics, urinary excretion proportions of antibiotics at low-dose exposure and pharmacokinetic data of antibiotics in humans, and the repeated sampling over a long period in future research is needed. Longitudinal studies about antibiotic exposure and the risk of diseases in different developmental windows as well as in-depth research on the pathogenic mechanism of long-term, low-dose, and joint antibiotic exposure are warranted.

Invasive non-typhoidal Salmonella infections in sub-Saharan Africa: a systematic review on antimicrobial resistance and treatment

BACKGROUND

Non-typhoidal Salmonella (NTS) are a frequent cause of invasive infections in sub-Saharan Africa. They are frequently multidrug resistant (co-resistant to ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol), and resistance to third-generation cephalosporin and fluoroquinolone non-susceptibility have been reported. Third-generation cephalosporins and fluoroquinolones are often used to treat invasive NTS infections, but azithromycin might be an alternative. However, data on antibiotic treatment efficacy in invasive NTS infections are lacking. In this study, we aimed to assess the spatiotemporal distribution of antimicrobial resistance in invasive NTS infections in sub-Saharan Africa and to describe the available evidence and recommendations on antimicrobial treatment.

METHODS

We conducted a systematic review of all available literature on antimicrobial resistance and treatment in invasive NTS infections. We performed a random effects meta-analysis to assess the temporal distribution of multidrug resistance, third-generation cephalosporin resistance, and fluoroquinolone non-susceptibility. We mapped these data to assess the spatial distribution. We provided a narrative synthesis of the available evidence and recommendations on antimicrobial treatment.

RESULTS

Since 2001, multidrug resistance was observed in 75% of NTS isolates from all sub-Saharan African regions (95% confidence interval, 70-80% and 65-84%). Third-generation cephalosporin resistance emerged in all sub-Saharan African regions and was present in 5% (95% confidence interval, 1-10%) after 2010. Fluoroquinolone non-susceptibility emerged in all sub-Saharan African regions but did not increase over time. Azithromycin resistance was reported in DR Congo. There were no reports on carbapenem resistance. We did not find high-quality evidence on the efficacy of antimicrobial treatment. There were no supranational guidelines. The "Access group" antibiotics ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol and "Watch group" antibiotics ceftriaxone, cefotaxime, and ciprofloxacin were recommended as the first-choice antibiotics in national guidelines or reviews. These also recommended (a switch to) oral fluoroquinolones or azithromycin.

CONCLUSIONS

In addition to the widespread multidrug resistance in invasive NTS infections in sub-Saharan Africa, resistance to third-generation cephalosporins and fluoroquinolone non-susceptibility was present in all regions. There was a lack of data on the efficacy of antimicrobial treatment in these infections, and supranational evidence-based guidelines were absent.

The Use of Systemic and Topical Fluoroquinolones

Appropriate prescribing practices for fluoroquinolones, as well as all antimicrobial agents, are essential as evolving resistance patterns are considered, additional treatment indications are identified, and the toxicity profile of fluoroquinolones in children has become better defined. Earlier recommendations for systemic therapy remain; expanded uses of fluoroquinolones for the treatment of certain infections are outlined in this report. Prescribing clinicians should be aware of specific adverse reactions associated with fluoroquinolones, and their use in children should continue to be limited to the treatment of infections for which no safe and effective alternative exists or in situations in which oral fluoroquinolone treatment represents a reasonable alternative to parenteral antimicrobial therapy.

Safety Concerns Surrounding Quinolone Use in Children

Fluoroquinolones are highly effective antibiotics with many desirable pharmacokinetic and pharmacodynamic properties including high bioavailability, large volume of distribution, and a broad spectrum of antimicrobial activity. Despite their attractive profile as anti-infective agents, their use in children is limited, primarily due to safety concerns. In this review we highlight the pharmacological properties of fluoroquinolones and describe their current use in pediatrics. In addition, we provide a comprehensive assessment of the safety data associated with fluoroquinolone use in children. Although permanent or destructive arthropathy remains a significant concern, currently available data demonstrate that arthralgia and arthropathy are relatively uncommon in children and resolve following cessation of fluoroquinolone exposure without resulting in long-term sequelae. The concern for safety and risk of adverse events associated with pediatric fluoroquinolone use is likely driving the limited prescribing of this drug class in pediatrics. However, in adults, fluoroquinolones are the most commonly prescribed broad-spectrum antibiotics, resulting in the development of drug-resistant bacteria that can be challenging to treat effectively. The consequence of misuse and overuse of fluoroquinolones leading to drug resistance is a greater, but frequently overlooked, safety concern that applies to both children and adults and one that should be considered at the point of prescribing.

Safety and tolerability profile of second-line anti-tuberculosis medications

Tuberculosis (TB) remains a major public health problem, representing the second leading cause of death from infectious diseases globally, despite being nearly 100 % curable. Multidrug-resistant (MDR)-TB, a form of TB resistant to isoniazid and rifampicin (rifampin), two of the key first-line TB drugs, is becoming increasingly common. MDR-TB is treated with a combination of drugs that are less effective but more toxic than isoniazid and rifampicin. These drugs include fluoroquinolones, aminoglycosides, ethionamide, cycloserine, aminosalicyclic acid, linezolid and clofazimine among others. Minor adverse effects are quite common and they can be easily managed with symptomatic treatment. However, some adverse effects can be life-threatening, e.g. nephrotoxicity due to aminoglycosides, cardiotoxicity due to fluoroquinolones, gastrointestinal toxicity due to ethionamide or para-aminosalicylic acid, central nervous system toxicity due to cycloserine, etc. Baseline evaluation may help to identify patients who are at increased risk for adverse effects. Regular clinical and laboratory evaluation during treatment is very important to prevent adverse effects from becoming serious. Timely and intensive monitoring for, and management of adverse effects caused by, second-line drugs are essential components of drug-resistant TB control programmes; poor management of adverse effects increases the risk of non-adherence or irregular adherence to treatment, and may result in death or permanent morbidity. Treating physicians should have a thorough knowledge of the adverse effects associated with the use of second-line anti-TB drugs, and routinely monitor the occurrence of adverse drug reactions. In this review, we have compiled safety and tolerability information regarding second-line anti-TB drugs in both adults and children.

Appropriate use of fluoroquinolones in children

With the increasing resistance to antibiotics among common bacterial pathogens, challenges associated with the use of fluoroquinolones (FQs) in paediatrics have emerged. The majority of FQs have favourable pharmacokinetic properties, although these properties can differ in children compared with adults. Moreover, all FQs have broad antimicrobial activity both against Gram-positive and Gram-negative bacteria. However, only some FQs for which adequate studies are available have been approved for use in children in a limited number of clinical situations owing to the supposed risk of development of severe musculoskeletal disorders, as demonstrated in juvenile animals. Recent short- and long-term evaluations appear to indicate that, at least for levofloxacin, this risk, if present at all, is marginal. This marginal risk could lead to more frequent use of FQs in children, even to treat diseases for which several other drugs with documented efficacy, safety and tolerability are considered the first-line antibiotics. However, for most of the FQs, adequate long-term studies of safety are not available. This indicates that the use of FQs should be limited to selected respiratory infections (including tuberculosis), exacerbation of lung disease in cystic fibrosis, central nervous system infections, enteric infections, febrile neutropenia, as well as serious infections attributable to FQ-susceptible pathogen(s) in children with life-threatening allergies to alternative agents. When considering diseases that could benefit from the use of FQs, particular attention must be paid to the choice of drug and its dosage, considering that not all of the FQs have been evaluated in different diseases.

Moxifloxacin for the treatment of pulmonary tuberculosis in children: a single center experience

OBJECTIVE

To report our experience on the safety and tolerability of moxifloxacin for treating children affected by pulmonary TB.

STUDY DESIGN

Children receiving a moxifloxacin-containing anti-TB regimen were included in the study. Their medical records were revised at the end of follow-up.

METHODS

We describe nine children treated with moxifloxacin for pulmonary TB at Regina Margherita Children's Hospital (Turin, Italy) between 2007 and 2012. Moxifloxacin was administered orally at 10 mg/kg/day once daily (maximum dose = 400 mg/day) following World Health Organization indications. During treatment, patients were systematically assessed for the development of side effects.

RESULTS

Eight children were considered cured at the end of treatment; one child was lost to follow-up after 3 months of treatment. Two children had side effects during treatment: one developed arthritis of the ankle; the other had liver toxicity, whose relationship with moxifloxacin could not be ruled out. We did not observe any case of QT prolongation, central nervous system disorders, growth defects or gastrointestinal disturbances.

CONCLUSIONS

A moxifloxacin-containing regimen might be considered for the treatment of TB in children, especially for drug-resistant and extensive forms. However, vigilance for possible side effects is recommended, especially if other drugs are concomitantly used. Studies on wider populations are needed to better define the impact of long-term treatments with quinolones on children's growth and psychomotor development and to outline regulatory indications on moxifloxacin use in the pediatric setting.

Levofloxacin Pharmacokinetics in Children

Levofloxacin is a broad-spectrum fluoroquinolone antibiotic with activity against many pathogens that cause bacterial infections in children, including penicillin-resistant pneumococci. To provide dosing guidance for children, 3 single-dose, multicenter pharmacokinetic studies were conducted in 85 children in 5 age groups: 6 months to <2 years, 2 to <5 years, 5 to <10 years, 10 to <12 years, and 12 to 16 years. Each child received a single 7-mg/kg dose of levofloxacin (not to exceed 500 mg) intravenously or orally. Plasma and urine samples were collected through 24 hours after dose. Pharmacokinetic parameters were estimated and compared among the 5 age groups and to previously collected adult data. Levofloxacin absorption (as indicated by C(max) and t(max)) and distribution in children are not age dependent and are comparable to those in adults. Levofloxacin elimination (reflected by t1/2 and clearance), however, is age dependent. Children younger than 5 years of age clear levofloxacin nearly twice as fast (intravenous dose, 0.32+/-0.08 L/h/kg; oral dose, 0.28+/-0.05 L/h/kg) as adults and, as a result, have the total systemic exposure (area under the plasma drug concentration-time curve) approximately one half that of adults. The levofloxacin area under the plasma drug concentration-time curve (dose normalized) in children receiving a single dose of the oral liquid formulation is comparable to that in children receiving the intravenous formulation. To provide compatible levofloxacin exposures associated with clinical effectiveness and safety in adults, children > or =5 years need a daily dose of 10 mg/kg, whereas children 6 months to <5 years should receive 10 mg/kg every 12 hours.

The use of systemic and topical fluoroquinolones

Appropriate prescribing practices for fluoroquinolones are essential as evolving resistance patterns are considered, additional treatment indications are identified, and the toxicity profile of fluoroquinolones in children becomes better defined. Earlier recommendations for systemic therapy remain; expanded uses of fluoroquinolones for the treatment of certain infections are outlined in this report. Although fluoroquinolones are reasonably safe in children, clinicians should be aware of the specific adverse reactions. Use of fluoroquinolones in children should continue to be limited to treatment of infections for which no safe and effective alternative exists.

Changing trends in newborn sepsis in Sagamu, Nigeria: bacterial aetiology, risk factors and antibiotic susceptibility

AIM

Sepsis is a major contributor to newborn deaths in the developing world. The objective is to determine the prevalence of newborn sepsis, the bacterial pathogens and antibiotic sensitivity pattern of the isolates.

METHOD

A study of consecutive babies hospitalised in Sagamu, Nigeria, with risk factors for or clinical features of sepsis was retrospectively done between January 2006 and December 2007, and prospectively between January and December 2008. Positive blood culture defined neonatal sepsis, and the antibiotic sensitivity pattern of the organisms was also determined.

RESULTS

There were 1050 admissions, and 174 (16.5%) babies had positive blood culture. Of the 527 babies with risk factors and clinical features of sepsis, 174 (33.3%) had confirmed sepsis: 119 (22.5%) had early-onset sepsis, while 55 (10.4%) had late-onset sepsis. The incidence of neonatal sepsis in the hospital was 51.3/1000 live births. Weight less than 1.5 kg, prolonged labour, prolonged rupture of membranes and lower socio-economic status were risk factors for sepsis. Staphylococcus aureus (31.0%), Klebsiella (23.0%), and coagulase-negative Staphylococcus (12.6%) and Escherichia coli (11.0%) were the leading aetiologies. The isolates were most sensitive to levofloxacin (95.7%), ofloxacin (95.1%), cefotaxime (86.7%) and ceftazidime (81.3%). Their sensitivity was 56.4% to cefuroxime and gentamicin, which are commonly used.

CONCLUSION

The prevalence of sepsis was high in this cohort of high-risk infants. The low in vitro sensitivity of the leading microbes to commonly used drugs is challenging. Guidelines on the reduction of emergence of drug resistance must be provided and instituted in newborn units.

[Quinolones]

Quinolones act by inhibiting enzymes (topoisomerases) that are essential for DNA synthesis, and probably by fragmentation of chromosomal DNA. The bactericidal activity of these drugs depends on their concentration. Their spectrum has been broadened, particularly since the introduction of a fluorine atom at position 6 (fluorquinolones). Quinolones are used in a large variety of in-hospital and community infections, as the treatment of choice or as alternative therapy. Depending on the specific compound, they are used in urinary tract infections, sexually transmitted diseases, chronic osteomyelitis, respiratory tract infections, and severe systemic infections, among others. The emergence and spread of resistance to quinolones has limited their use in some conditions and may affect their application in the future. Strategies currently exist to minimize the spread of resistance. Quinolones are well tolerated and safe. The most common adverse effects involve the gastrointestinal tract and central nervous system.

Preparing families with children traveling to developing countries

The experience of international travel can be very gratifying. But illness, visits to the doctor, and disability should not be part of travel. Diseases such as malaria, yellow fever, traveler's diarrhea, and hepatitis A are preventable. Through the administration of vaccines, the prescribing of prophylactic medications, and by providing disease-prevention education, clinicians can help assure their pediatric travelers and their families will have an enjoyable and rewarding travel experience.

Antibiotic-resistant Staphylococcus aureus in community-acquired pediatric neck abscesses

OBJECTIVE

To determine the microbiology, particularly the prevalence of MRSA, in pediatric patients with community-acquired bacterial lymphadenitis. Long considered a nosocomial organism, methicillin-resistant Staphylococcus aureus (MRSA) has recently emerged as a cause of community-acquired infections. Resistance to other classes of antibiotics, including clindamycin, is prevalent amongst S. aureus, as well.

METHODS

A retrospective review of the medical records and culture results of patients under the age of 18 who underwent trans-cervical surgical drainage of abscessed lymph nodes between the years 2000 and 2006.

RESULTS

Sixty-two patients were identified for whom microbiology data were available. Six infections were classified as parapharyngeal on imaging; the remainder involved cervical chain lymph nodes. Forty-nine patients grew microorganisms on culture while 13 collections had no growth. The most common organism was S. aureus (63% of positive cultures); followed by beta-hemolytic group A Streptococcus (22%). Of S. aureus isolates, 27% were oxacillin-resistant (MRSA). All MRSA isolates were sensitive to clindamycin and trimethoprim/sulfamethoxazole; 63% were sensitive to ciprofloxacin, and 25% sensitive to erythromycin. Of methicillin-sensitive S. aureus isolates, 100, 86, and 82% were sensitive to trimethoprim/sulfamethoxazole, clindamycin, and ciprofloxacin, respectively. All MRSA isolates were identified during the latter half of the study period (2003-2006); none grew prior to 2003.

CONCLUSIONS

MRSA is a common pathogen in community-acquired lymphadenitis, and its incidence is rising. Resistance to clindamycin, a drug commonly used to treat MRSA, is prevalent amongst methicillin-sensitive S. aureus. This has important implications regarding the empiric treatment of lymphadenitis in children.

Additive effects of ciprofloxacin on the in-vitro activity of chloroquine against a clinical isolate of Plasmodium falciparum

As chloroquine and ciprofloxacin each possess substantial inhibitory activity against the schizonts of Plasmodium falciparum, it seems possible that a combination of the two drugs may be clinically useful. The effects on the erythrocytic stages of P. falciparum of combined treatment with chloroquine and ciprofloxacin were therefore evaluated in vitro, using the World Health Organization's standardized micro test. When used alone, the median inhibitory concentration (IC(50)) of chloroquine against the schizonts in the assay mixtures was found to be 7.75 microg/ml, whereas the corresponding value for ciprofloxacin was markedly lower, at 3.35 microg/ml. When they were used together, however, there was marked and statistically significant mutual enhancement of schizont inhibition by the two drugs, indicating that a chloroquine-ciprofloxacin combination may be useful clinically, in the treatment and management of P. falciparum malaria.

Pseudomonas aeruginosa: resistance and therapeutic options at the turn of the new millennium

Pseudomonas aeruginosa is a major cause of nosocomial infections. This organism shows a remarkable capacity to resist antibiotics, either intrinsically (because of constitutive expression of beta-lactamases and efflux pumps, combined with low permeability of the outer-membrane) or following acquisition of resistance genes (e.g., genes for beta-lactamases, or enzymes inactivating aminoglycosides or modifying their target), over-expression of efflux pumps, decreased expression of porins, or mutations in quinolone targets. Worryingly, these mechanisms are often present simultaneously, thereby conferring multiresistant phenotypes. Susceptibility testing is therefore crucial in clinical practice. Empirical treatment usually involves combination therapy, selected on the basis of known local epidemiology (usually a beta-lactam plus an aminoglycoside or a fluoroquinolone). However, therapy should be simplified as soon as possible, based on susceptibility data and the patient's clinical evolution. Alternative drugs (e.g., colistin) have proven useful against multiresistant strains, but innovative therapeutic options for the future remain scarce, while attempts to develop vaccines have been unsuccessful to date. Among broad-spectrum antibiotics in development, ceftobiprole, sitafloxacin and doripenem show interesting in-vitro activity, although the first two molecules have been evaluated in clinics only against Gram-positive organisms. Doripenem has received a fast track designation from the US Food and Drug Administration for the treatment of nosocomial pneumonia. Pump inhibitors are undergoing phase I trials in cystic fibrosis patients. Therefore, selecting appropriate antibiotics and optimising their use on the basis of pharmacodynamic concepts currently remains the best way of coping with pseudomonal infections.

Community-based therapy for children with multidrug-resistant tuberculosis

OBJECTIVES

The goals were to describe the management of multidrug-resistant tuberculosis among children, to examine the tolerability of second-line antituberculosis agents among children, and to report the outcomes of children treated for multidrug-resistant tuberculosis in poor urban communities in Lima, Peru, a city with high tuberculosis prevalence.

METHODS

A retrospective analysis of data for 38 children <15 years of age with multidrug-resistant tuberculosis, either documented with drug sensitivity testing of the child's tuberculosis isolate or suspected on the basis of the presence of clinical symptoms for a child with a household contact with documented multidrug-resistant tuberculosis, was performed. All 38 children initiated a supervised individualized treatment regimen for multidrug-resistant tuberculosis between July 1999 and July 2003. Each child received 18 to 24 months of therapy with > or =5 first- or second-line drugs to which their Mycobacterium tuberculosis strain was presumed to be sensitive.

RESULTS

Forty-five percent of the children had malnutrition or anemia at the time of diagnosis, 29% had severe radiographic findings (defined as bilateral or cavitary disease), and 13% had extrapulmonary disease. Forty-five percent of the children were hospitalized initially because of the severity of illness. Adverse events were observed for 42% of the children, but no events required suspension of therapy for >5 days. Ninety-five percent of the children (36 of 38 children) achieved cures or probable cures, 1 child (2.5%) died, and 1 child (2.5%) defaulted from therapy.

CONCLUSIONS

Multidrug-resistant tuberculosis disease among children can be treated successfully in resource-poor settings. Treatment is well tolerated by children, and severe adverse events with second-line agents are rare.

Randomized, investigator-blinded, multicenter study of gatifloxacin versus amoxicillin/clavulanate treatment of recurrent and nonresponsive otitis media in children

BACKGROUND

Decreased susceptibility of pathogens to currently used agents for recurrent otitis media has provided the impetus for identifying new antimicrobial options.

OBJECTIVE

To compare gatifloxacin with amoxicillin/clavulanate in children with recurrent or nonresponsive acute otitis media (AOM).

METHODS

Included in this multicenter randomized trial were 413 patients, ranging in age from 6 months to 7 years, who had recurrent AOM (at least 3 episodes in the previous 6 months or 4 episodes in the previous 12 months) and/or had failed antibiotic therapy for AOM within 14 days of enrollment. Diagnosis required evidence of acute inflammation and otoscopic findings of middle ear effusion; baseline tympanocentesis was optional and encouraged. Children were randomly assigned (2:1) to 10 days of oral therapy with gatifloxacin suspension (10 mg/kg of body weight once daily) or amoxicillin/clavulanate suspension (45/6.4 mg/kg/d in 2 divided doses).

RESULTS

: Clinical cure was obtained in 90.2% (222 of 246) of patients in the gatifloxacin group and 84.3% (102 of 121) of those in the amoxicillin/clavulanate group (95% confidence interval, -1.9-12.9) 3-10 days after treatment ended. Gatifloxacin was associated with higher clinical cure rates than was amoxicillin/clavulanate in children younger than 2 years of age (92.0% versus 80.0%, respectively). Cure rates by pretreatment pathogen in the gatifloxacin and amoxicillin/clavulanate groups were 92.1% (35 of 38) versus 88.9% (16 of 18) for Streptococcus pneumoniae infections and 88.2% (30 of 34) versus 92.3% (12 of 13) for Haemophilus influenzae infections, respectively. Sustained clinical cures 3-4 weeks after treatment ended were obtained in 74.4% (183 of 246) of patients treated with gatifloxacin and 72.7% (88 of 121) of those treated with amoxicillin/clavulanate. Adverse events considered drug-related occurred with similar frequency in the 2 groups. Six patients (2.2%) in the gatifloxacin group and 2 patients (1.5%) in the amoxicillin/clavulanate group developed transient symptoms of mild or moderate arthralgia.

CONCLUSIONS

In this comparative evaluation of fluoroquinolone therapy in children with AOM, gatifloxacin was similar in clinical efficacy to amoxicillin/clavulanate 45/6.4 mg/kg/d for treatment of recurrent/nonresponsive infections.

Randomized, investigator-blinded, multicenter, comparative study of gatifloxacin versus amoxicillin/clavulanate in recurrent otitis media and acute otitis media treatment failure in children

BACKGROUND

Recurrent otitis media and acute otitis media treatment failure are commonly encountered in the pediatric population.

OBJECTIVE

To compare the clinical efficacy of gatifloxacin with amoxicillin/clavulanate for the treatment of acute otitis media treatment failure and recurrent otitis media.

METHODS

Three hundred fifty-four children 6 months-7 years with recurrent otitis media and/or acute otitis media failure were stratified according to age (younger than 2 years versus 2 years or older) and then randomly assigned to 10 days of treatment with gatifloxacin 10 mg/kg once daily or amoxicillin/clavulanate 90 mg/6.4 mg in 2 divided doses. Tympanocentesis was performed in 116 children with acute otitis media treatment failure and 52 with recurrent otitis media at study entry to validate the clinical diagnosis and provide microbiologic data. The primary outcome measure was clinical resolution of infection at the test-of-cure visit 3-10 days after completing treatment.

RESULTS

Clinical resolution of acute otitis media was observed in 79.0% (49 of 62) of clinically evaluable children younger than 2 years and 90.3% (56 of 62) of those 2 years or older who were treated with gatifloxacin as compared with 77.6% (45 of 58) of children younger than 2 years and 79.7% (47 of 59) of children 2 years or older treated with amoxicillin/clavulanate. In patients with acute otitis media treatment failure, clinical response rates for children younger than 2 years and those 2 years or older were 87.5% (21 of 24) and 97.0% (32 of 33) with gatifloxacin versus 63.6% (14 of 22) and 83.9% (26 of 31) with amoxicillin/clavulanate. The corresponding clinical response rates in patients with recurrent otitis media were 79.2% (19 of 24) and 85.7% (18 of 21) with gatifloxacin and 90.5% (19 of 21) and 76.0% (19 of 25) with amoxicillin/clavulanate. Clinical success in those subjects having pretreatment middle ear fluid pathogens was similar for the 2 regimens [80.0% (24 of 30) gatifloxacin, 77.1% (27 of 35) amoxicillin/clavulanate]. Emergence of fluoroquinolone-resistant strains was not observed. Both drugs were generally well-tolerated. Diarrhea was the most common drug-related adverse event (10% gatifloxacin, 18% amoxicillin/clavulanate). No evidence of abnormal joint or gait findings was found during a 12-month follow-up.

CONCLUSIONS

Gatifloxacin once daily is at least as effective and well-tolerated as amoxicillin/clavulanate twice daily in children with acute otitis media treatment failure or recurrent otitis media. There was no evidence of arthrotoxicity or emergence of fluoroquinolone-resistant bacteria in gatifloxacin-treated children.

Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000

From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.

Preparing children for travel to tropical and developing regions

Visiting a grandparent for a first time, exploring the ruins of an ancient civilization in a distant country, or river rafting through a tropical jungle are all moments that are never forgotten. Illness, visits to the doctor, and disability should not be a part of these experiences. Diseases such as malaria, yellow fever, travelers' diarrhea, and hepatitis A are preventable. Through the use of vaccines, prophylactic medications, and disease-prevention education, clinicians may help ensure their pediatric patients have enjoyable and rewarding travel experiences.

Population pharmacokinetics of ciprofloxacin in pediatric and adolescent patients with acute infections

The aim of the present study was to characterize the population pharmacokinetics of ciprofloxacin in patients with and without cystic fibrosis ranging in age from 1 day to 24 years and to propose a limited sampling strategy to estimate individual pharmacokinetic parameters. Patients were divided into four groups according to the treatment schedule. They received ciprofloxacin by intravenous infusion (30 min) or by the oral route. The number of samples collected from each patient ranged from 1 to 12. The population parameters were computed for an initial group of 37 patients. The data were analyzed by nonlinear mixed-effect modeling by use of a two-compartment structural model. The interindividual variability in clearance (CL) was partially explained by a dependence on age and the patient's clinical status. In addition, a significant relationship was found between weight and the initial volume of distribution. Eighteen additional patients were used for model validation and evaluation of limited sampling strategies. When ciprofloxacin was administered intravenously, sampling at a single point (12 h after the start of infusion) allowed the precise and accurate estimation of CL and the elimination half-life, as well as the ciprofloxacin concentration at the end of the infusion. It should be noted that to take into account the presence of a lag time after oral administration, a schedule based on two sampling times of 1 and 12 h is needed. The results of this study combine relationships between ciprofloxacin pharmacokinetic parameters and patient covariates that may be useful for dose adjustment and a convenient sampling procedure that can be used for further studies.

Pseudomonas infections in the thermally injured patient

Pseudomonas aeruginosa, remains a serious cause of infection and septic mortality in burn patients, particularly when nosocomially acquired. A prototypic burn patient who developed serious nosocomially acquired Pseudomonas infection is described as an index case which initiated investigations and measures taken to identify the source of the infection. The effect of changes in wound care to avoid further nosocomial infections was measured to provide data on outcome and cost of care. The bacteriology of Pseudomonas is reviewed to increase the burn care providers understanding of the behaviour of this very common and serious pathogen in the burn care setting, before reviewing the approach to detection of the organism and treatment both medically and surgically. After controlling the nosocomial spread of Pseudomonas in our burn unit, we investigated the morbidity and mortality associated with nosocomial infection with an aminoglycoside resistant Pseudomonas and the associated costs compared to a group of case-matched control patients with similar severity of burn injury, that did not acquire resistant Pseudomonas during hospitalization at our institution. We found a significant increase in the mortality rate in the Pseudomonas group compared to controls. The morbidity in terms of length of stay, ventilator days, number of surgical procedures, and the amount of blood products used were all significantly higher in the Pseudomonas group compared to controls. Costs associated with antibiotic requirements were also significantly higher in the Pseudomonas group. Despite this increased resource consumption necessary to treat Pseudomonas infections, these efforts did not prevent significantly higher mortality rates when compared to control patients who avoided infection with the resistant organism. Thus, in addition to the specific measures required to identify and treat nosocomial Pseudomonas infections in burn patients, prevention of infection through modification of treatment protocols together with continuous infection control measures to afford early identification and eradication of nosocomial Pseudomonas infection are critical for cost-effective, successful burn care.

Ciprofloxacin-induced renal insufficiency in cystic fibrosis

Acute renal insufficiency is known to occur in patients who are taking ciprofloxacin, particularly the elderly. We report two young patients with cystic fibrosis who presented with acute renal insufficiency after 2-3 weeks of oral ciprofloxacin therapy. The incidence of this adverse effect in children and young adults who have cystic fibrosis is unknown. Multiple mechanisms for ciprofloxacin-induced nephrotoxicity have been proposed.

Susceptibilities to levofloxacin in Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis clinical isolates from children: results from 2000-2001 and 2001-2002 TRUST studies in the United States

Among respiratory tract isolates of Streptococcus pneumoniae from children, resistance to penicillins, cephalosporins, macrolides, and trimethoprim-sulfamethoxazole (SXT) increases on an annual basis. Pediatric patients who do not respond to conventional therapy for respiratory tract infections someday may be treated with fluoroquinolones. In this study, MICs of beta-lactams, azithromycin, SXT, and levofloxacin were determined and interpreted by using NCCLS guidelines for isolates of S. pneumoniae (2,834 from children and 10,966 from adults), Haemophilus influenzae (629 from children and 2,281 from adults), and Moraxella catarrhalis (389 from children and 1,357 from adults) collected during the 2000-2001 and 2001-2002 respiratory illness seasons in the United States as part of the ongoing TRUST surveillance studies. Rates of resistance to penicillin, azithromycin, and SXT were > or = 7.5% higher among patients < or = 4 years old than among patients 5 to 10, 11 to 17, and > or = 18 years old in both the 2000-2001 and the 2001-2002 respiratory illness seasons. Levofloxacin resistance was detected in 2 of 2,834 isolates (0.07%) from patients <18 years old. Levofloxacin MICs of 0.25 to 1 micro g/ml accounted for 99.6, 99.5, 99.3, 99.7, 98.4, and 98.0% of isolates from patients < 2, 2 to 4, 5 to 10, 11 to 17, 18 to 64, and > 64 years old. Multidrug resistance was twice as common among patients < or = 4 years old (25.3%) as among patients 5 to 10 years old (13.7%), 11 to 17 years old (11.9%), 18 to 64 years old (12.1%), and > 64 years old (12.4%). The most common multidrug resistance phenotype in S. pneumoniae isolates for all age groups was resistance to penicillin, azithromycin, and SXT (70.3 to 76.6%). For H. influenzae and M. catarrhalis isolates from patients < 2, 2 to 4, 5 to 10, 11 to 17, 18 to 64, and > 64 years old, levofloxacin MICs at which 90% of the isolates were inhibited were 0.015 and 0.03 to 0.06 microg/ml, respectively, in the 2000-2001 and 2001-2002 respiratory illness seasons. In the 2000-2001 and 2001-2002 respiratory illness season surveillance studies in the United States, 99.9% of pediatric isolates of S. pneumoniae were susceptible to levofloxacin. If fluoroquinolones become a treatment option for pediatric patients, careful monitoring of fluoroquinolone susceptibilities will be increasingly important in future surveillance studies.

Preparing the traveller

The four steps for giving travellers the foundation for healthy journeys are to assess their health, analyse their itineraries, select vaccines, and provide education about prevention and self-treatment of travel-related diseases. This process takes time. Since there is a risk of information overload, travellers should leave the clinic with some written advice for reinforcement. The order of these steps can be tailored to what best suits the travel clinic, but vaccinating early in the process allows monitoring for adverse reactions. Face-to-face discussion is vital for explaining the use and side-effects of medications. Those who provide a travel medicine service should be seeing many travellers and should seek specialist training. In 2003, the International Society of Travel Medicine introduced a certificate of knowledge examination in travel medicine. We cannot make travellers bullet-proof but it is possible to make them bullet-resistant. The pre-travel visit should minimise health risks specific to the journey, give travellers the capability to handle most minor medical problems, and allow them to identify when to seek local care during the trip or on return.

Penetration of topically administered ofloxacin and trimethoprim into aqueous humor

Ocular penetration of two topical antibiotics used to treat bacterial conjunctivitis was assessed in adult volunteers scheduled for cataract surgery. In this randomized, parallel-group study, patients instilled trimethoprim sulfate 0.1%/polymyxin B (n = 23) or ofloxacin 0.3% (n = 25) QID for 3 days, plus 4 instillations in the hour before surgery. Analysis of aqueous humor samples obtained during surgery showed a 2.4-fold greater concentration of ofloxacin over trimethoprim (1.135 micro g/ml vs 0.470 micro g/ml; P <.0001). The greater concentration of ofloxacin in ocular tissue coupled with its superior antibacterial activity profile supports its use as an alternative to trimethoprim/polymyxin B for treatment of bacterial conjunctivitis.

Elective bone marrow transplantation in a child with X-linked hyper-IgM syndrome presenting with acute respiratory distress syndrome

We describe a 10-month-old boy diagnosed with X-linked hyper-IgM syndrome (XHIM) after suffering from life-threatening acute respiratory distress syndrome (ARDS) caused by Pneumocystis carinii pneumonia (PCP), although his previous clinical history and first level laboratory tests investigating immunological function did not indicate immunodeficiency. When the patient's overall condition was good, elective bone marrow transplantation from an HLA-matched older brother was performed successfully. We describe how correct diagnosis and successful treatment were made possible thanks to the involvement of a network of specialists.

Use of anti-infective agents during lactation: Part 2--Aminoglycosides, macrolides, quinolones, sulfonamides, trimethoprim, tetracyclines, chloramphenicol, clindamycin, and metronidazole

Because many antibiotics are excreted into breast milk, it can be difficult for a practitioner to choose an antibiotic for a lactating patient that will have minimal risks to her nursing infant. This article is the second of a three-part series discussing the use of anti-infective agents during lactation. The authors review general information regarding use and common side effects for several classes of antibiotics. They also summarize information, including documented milk concentrations, milk-to-plasma ratios, and other pharmacokinetic properties, in a table that can help practitioners choose antibiotics that may be considered safe to use in the lactating mother.

A Risk-Benefit Assessment of Levofloxacin in Respiratory, Skin and Skin Structure, and Urinary Tract Infections

As a class, the quinolone antibacterials can no longer be assumed to be both effective and relatively free of significant adverse effects. Recent safety issues with newer generation fluoroquinolones, and concerns regarding drug-use associated bacterial resistance have made all drugs in this class subject to intense scrutiny and further study. Levofloxacin is a second generation fluoroquinolone with a post marketing history of well tolerated and successful use in a variety of clinical situations. Quinolones as a class cause a variety of adverse effects, including phototoxicity, seizures and other CNS disturbances, tendonitis and arthropathies, gastrointestinal effects, nephrotoxicity, prolonged QTc interval and torsade de pointes, hypo- or hyperglycaemia, and hypersensitivity reactions. Levofloxacin has been involved in only a few case reports of adverse events, which include QTc prolongation, seizures, glucose disturbances, and tendonitis. Levofloxacin has been shown to be effective at dosages of 250mg to 500mg once-daily in clinical trials in the management of acute maxillary sinusitis, acute bacterial exacerbations of chronic bronchitis, community-acquired pneumonia, skin and skin structure infections, and urinary tract infections. There are data suggesting that levofloxacin may promote fluoroquinolone resistance among the Streptococcus pneumoniae, and that clinical failures may result from this therapy. Other data suggest that fluoroquinolones with lower potency against Pseudomonas aeruginosa than ciprofloxacin, such as levofloxacin, may drive class-wide resistance to this pathogen. Levofloxacin is an effective drug in many clinical situations, but its cost is significantly higher than amoxicillin, erythromycin, or first and second generation cefalosporins. Because of the propensity to select for fluoroquinolone resistance in the pneumococcus and potentially other pathogens, levofloxacin should be an alternative agent rather than a drug-of-choice in routine community-acquired respiratory tract, urinary tract, and skin or skin structure infections. In areas with increasing pneumococcal beta-lactam resistance, levofloxacin may be a reasonable empiric therapy in community-acquired respiratory tract infections. Similarly, in patients with risk factors for infectious complications or poor outcome, levofloxacin may be an excellent empiric choice in severe community-acquired respiratory tract infections, urinary tract infections, complicated skin or skin structure infections, and nosocomial respiratory and urinary tract infections. Better clinical data are needed to identify the true place in therapy of the newer fluoroquinolones in common community-acquired and nosocomial infections. Until then, these agents, including levofloxacin, might best be reserved for complicated infections, infection recurrence, and infections caused by beta-lactam or macrolide-resistant pathogens.