Treatment of community-acquired acute uncomplicated urinary tract infection with sparfloxacin versus ofloxacin. The Sparfloxacin Multi Center UUTI Study Group

Diagnosis and treatment of urinary tract infections across age groups

Urinary tract infections are the most common outpatient infections, but predicting the probability of urinary tract infections through symptoms and test results can be complex. The most diagnostic symptoms of urinary tract infections include change in frequency, dysuria, urgency, and presence or absence of vaginal discharge, but urinary tract infections may present differently in older women. Dipstick urinalysis is popular for its availability and usefulness, but results must be interpreted in context of the patient's pretest probability based on symptoms and characteristics. In patients with a high probability of urinary tract infection based on symptoms, negative dipstick urinalysis does not rule out urinary tract infection. Nitrites are likely more sensitive and specific than other dipstick components for urinary tract infection, particularly in the elderly. Positive dipstick testing is likely specific for asymptomatic bacteriuria in pregnancy, but urine culture is still the test of choice. Microscopic urinalysis is likely comparable to dipstick urinalysis as a screening test. Bacteriuria is more specific and sensitive than pyuria for detecting urinary tract infection, even in older women and during pregnancy. Pyuria is commonly found in the absence of infection, particularly in older adults with lower urinary tract symptoms such as incontinence. Positive testing may increase the probability of urinary tract infection, but initiation of treatment should take into account risk of urinary tract infection based on symptoms as well. In cases in which the probability of urinary tract infection is moderate or unclear, urine culture should be performed. Urine culture is the gold standard for detection of urinary tract infection. However, asymptomatic bacteriuria is common, particularly in older women, and should not be treated with antibiotics. Conversely, in symptomatic women, even growth as low as 10² colony-forming unit/mL could reflect infection. Resistance is increasing to fluoroquinolones, beta-lactams, and trimethoprim-sulfamethoxazole. Most uropathogens still display good sensitivity to nitrofurantoin. First-line treatments for urinary tract infection include nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole (when resistance levels are <20%). These antibiotics have minimal collateral damage and resistance. In pregnancy, beta-lactams, nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole can be appropriate treatments. Interpreting the probability of urinary tract infection based on symptoms and testing allows for greater accuracy in diagnosis of urinary tract infection, decreasing overtreatment and encouraging antimicrobial stewardship.

Management of urinary tract infection in solid organ transplant recipients: Consensus statement of the Group for the Study of Infection in Transplant Recipients (GESITRA) of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Network for Research in Infectious Diseases (REIPI)

BACKGROUND

Urinary tract infections (UTIs) are one of the most common infections in solid organ transplant (SOT) recipients.

METHODS

Experienced SOT researchers and clinicians have developed and implemented this consensus document in support of the optimal management of these patients. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation. This article was written in accordance with international recommendations on consensus statements and the recommendations of the Appraisal of Guidelines for Research and Evaluation II (AGREE II).

RESULTS

Recommendations are provided on the management of asymptomatic bacteriuria, and prophylaxis and treatment of UTI in SOT recipients. The diagnostic-therapeutic management of recurrent UTI and the role of infection in kidney graft rejection or dysfunction are reviewed. Finally, recommendations on antimicrobials and immunosuppressant interactions are also included.

CONCLUSIONS

The latest scientific information on UTI in SOT is incorporated in this consensus document.

Genetic determinants of antimicrobial resistance in Gram positive bacteria from organic foods

Bacterial biocide resistance is becoming a matter of concern. In the present study, a collection of biocide-resistant, Gram-positive bacteria from organic foods (including 11 isolates from genus Bacillus, 25 from Enterococcus and 10 from Staphylococcus) were analyzed for genes associated to biocide resistance efflux pumps and antibiotic resistance. The only qac-genes detected were qacA/B (one Bacillus cereus isolate) and smr (one B. cereus and two Staphylococcus saprophyticus isolates). Efflux pump genes efrA and efrB genes were detected in Staphylococcus (60% of isolates), Bacillus (54.54%) and Enterococcus (24%); sugE was detected in Enterococcus (20%) and in one Bacillus licheniformis; mepA was detected in Staphylococcus (60%) and in one Enterococcus isolate (which also carried mdeA), and norE gene was detected only in one Enterococcus faecium and one S. saprophyticus isolate. An amplicon for acrB efflux pump was detected in all but one isolate. When minimal inhibitory concentrations (MICs) were determined, it was found that the addition of reserpine reduced the MICs by eight fold for most of the biocides and isolates, corroborating the role of efflux pumps in biocide resistance. Erythromycin resistance gene ermB was detected in 90% of Bacillus isolates, and in one Staphylococcus, while ereA was detected only in one Bacillus and one Staphyloccus, and ereB only in one Staphylococcus. The ATP-dependent msrA gene (which confers resistance to macrolides, lincosamides and type B streptogramins) was detected in 60% of Bacillus isolates and in all staphylococci, which in addition carried msrB. The lincosamide and streptogramin A resistance gene lsa was detected in Staphylococcus (40%), Bacillus (27.27%) and Enterococcus (8%) isolates. The aminoglycoside resistance determinant aph (3_)-IIIa was detected in Staphylococcus (40%) and Bacillus (one isolate), aph(2_)-1d in Bacillus (27.27%) and Enterococcus (8%), aph(2_)-Ib in Bacillus (one isolate), and the bifunctional aac(6_)1e-aph(2_)-Ia in Staphylococcus (20%), Enterococcus (8%) and Bacillus (one isolate). Chloramphenicol resistance cat gene was detected in Enterococcus (8%) and Staphylococcus (20%), and blaZ only in Staphylococcus (20%). All other antibiotic or biocide resistance genes investigated were not detected in any isolate. Isolates carrying multiple biocide and antibiotic determinants were frequent among Bacillus (36.36%) and Staphylococcus (50%), but not Enterococcus. These results suggest that biocide and antibiotic determinants may be co-selected.

Identification of Staphylococcus saprophyticus isolated from patients with urinary tract infection using a simple set of biochemical tests correlating with 16S-23S interspace region molecular weight patterns

The emergence of Staphylococcus spp. not only as human pathogens, but also as reservoirs of antibiotic resistance determinants, requires the development of methods for their rapid and reliable identification in medically important samples. The aim of this study was to compare three phenotypic methods for the identification of Staphylococcus spp. isolated from patients with urinary tract infection using the PCR of the 16S-23S interspace region generating molecular weight patterns (ITR-PCR) as reference. All 57 S. saprophyticus studied were correctly identified using only the novobiocin disk. A rate of agreement of 98.0% was obtained for the simplified battery of biochemical tests in relation to ITR-PCR, whereas the Vitek I system and novobiocin disk showed 81.2% and 89.1% agreement, respectively. No other novobiocin-resistant non-S. saprophyticus strain was identified. Thus, the novobiocin disk is a feasible alternative for the identification of S. saprophyticus in urine samples in laboratories with limited resources. ITR-PCR and the simplified battery of biochemical tests were more reliable than the commercial systems currently available. This study confirms that automated systems are still unable to correctly differentiate CoNS species and that simple, reliable and inexpensive methods can be used for routine identification.

Antibiotic treatment of uncomplicated urinary tract infection in premenopausal women

Uncomplicated urinary tract infections (UTIs) in otherwise healthy premenopausal women are one of the most frequent infections in the community. Therefore any improvement in management will have a high impact not only on the quality of life of the individual patient but also on the health system. In placebo-controlled studies antimicrobial treatment was significantly more effective than placebo, but on the other hand showed more adverse events. The choice of antibiotic depends on the spectrum and susceptibility patterns of the uropathogens, its effectiveness for this indication, its tolerability, its collateral effects and cost. After a systematic literature search, recommendations for empiric treatment of acute uncomplicated cystitis and acute uncomplicated pyelonephritis and for follow-up strategies were developed.

International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases

A Panel of International Experts was convened by the Infectious Diseases Society of America (IDSA) in collaboration with the European Society for Microbiology and Infectious Diseases (ESCMID) to update the 1999 Uncomplicated Urinary Tract Infection Guidelines by the IDSA. Co-sponsoring organizations include the American Congress of Obstetricians and Gynecologists, American Urological Association, Association of Medical Microbiology and Infectious Diseases–Canada, and the Society for Academic Emergency Medicine. The focus of this work is treatment of women with acute uncomplicated cystitis and pyelonephritis, diagnoses limited in these guidelines to premenopausal, non-pregnant women with no known urological abnormalities or co-morbidities. The issues of in vitro resistance prevalence and the ecological adverse effects of antimicrobial therapy (collateral damage) were considered as important factors in making optimal treatment choices and thus are reflected in the rankings of recommendations.

Quinolones for uncomplicated acute cystitis in women

BACKGROUND

Uncomplicated acute cystitis is one of the most common bacterial infections in adults. The percentage of women who have at least one episode of acute cystitis is estimated to be between 40% to 50%. Quinolones are recommended for acute cystitis in regions where the level of resistance to other antimicrobials namely co-trimoxazole is high. However the efficacy, safety and tolerance of quinolones needs investigation.

OBJECTIVES

To compare the efficacy, safety and tolerance of different quinolones in women with uncomplicated acute cystitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library Issue 3, 2003), MEDLINE (1966 - September 2003), EMBASE (1988 - September 2003), reference lists of articles and abstracts from conference proceedings without language restriction. Reference lists of urology, infectious diseases and nephrology textbooks, review articles and relevant studies.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing two or more different quinolones in women (>/= 16 years) with uncomplicated acute cystitis were selected.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data. Statistical analyses were performed using the random effects model and the results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI).

MAIN RESULTS

We identified 11 studies enrolling 7535 women. There were no significant differences in clinical or microbiological efficacy between quinolones. Photosensitivity reactions were more frequently observed for sparfloxacin when compared to ofloxacin. Any adverse event, adverse events causing withdrawal, skin adverse events, photosensitivity reactions were more common for lomefloxacin when compared to norfloxacin. Any adverse event, adverse drug reactions, CNS adverse events were more common for ofloxacin when compared to ciprofloxacin. CNS adverse events and insomnia were more often reported for rufloxacin when compared to pefloxacin. Adverse drug reactions occurred frequently for ofloxacin than levofloxacin. Insomnia was reported more frequently for enoxacin than ciprofloxacin.

AUTHORS' CONCLUSIONS

We found no significant differences in clinical or microbiological efficacy between quinolones but some differences in occurrence and spectrum of quinolone safety.

Empirical treatment of acute cystitis in women

Empirical antimicrobial treatment for acute cystitis in women requires continuing reassessment as the antimicrobial susceptibility of community isolates of Escherichia coli evolves. Current recommendations for 3 days trimethoprim or trimethoprim/sulphamethoxazole are compromised by increasing resistance of community E. coli to these agents. Fluoroquinolones are an alternate 3-day therapy, but increasing resistance is being reported from some countries, and widespread community use may promote resistance, limiting effectiveness of these agents for more serious infections. Alternate regimens supported by recent clinical trials suggest pivmecillinam given twice daily for 7 days is as effective as 3 days of quinolone therapy, while microbiological cure is 80% with 3 days therapy twice daily, and 90% with 3 days therapy thrice daily. Nitrofurantoin given for 7 days has a cure rate of 80-85%. Fosfomycin trometamol as a single dose has cure rates of 75-85%. All these agents are effective, but a compromise in efficacy or duration of therapy compared with current 3-day regimens may have to be considered.

The current management strategies for community-acquired urinary tract infection

Acute uncomplicated UTI is one of the most common problems for which young women seek medical attention and accounts for considerable morbidity and health care costs. Acute cystitis or pyelonephritis in the adult patient should be considered uncomplicated if the patient is not pregnant or elderly, if there has been no recent instrumentation or antimicrobial treatment, and if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by E. coli, which are susceptible to many oral antimicrobials, although resistance is increasing to some of the commonly used agents, especially TMP-SMX. In women with risk factors for infection with resistant bacteria, or in the setting of a high prevalence of TMP-SMX-resistant uropathogens, a case can be made for using a fluoroquinolone or nitrofurantoin. Use of nitrofurantoin for the empiric treatment of mild cystitis is supportable from a public health perspective in an attempt to decrease uropathogen resistance because it does not share cross-resistance with more commonly prescribed antimicrobials. Beta-lactams and fosfomycin should be considered second-line agents for empiric treatment of cystitis. Acute pyelonephritis in an otherwise healthy woman may be considered an uncomplicated infection. Fluoroquinolone regimens are superior to TMP-SMX for empiric therapy because of the relatively high prevalence of TMP-SMX resistance among uropathogens causing pyelonephritis. TMP-SMX, effective for patients with mild to moderate disease, is an appropriate drug if the uropathogen is known to be susceptible. It is reasonable to use a 7- to 10-day oral fluoroquinolone regimen for outpatient management of mild to moderate pyelonephritis in the setting of a susceptible causative pathogen and rapid clinical response to therapy. Most women with acute uncomplicated pyelonephritis are now managed safely and effectively as outpatients. Acute uncomplicated cystitis or pyelonephritis in healthy adult men is very uncommon but is generally caused by the same spectrum of uropathogens with the same antimicrobial susceptibility profile as that seen in women. The choice of antimicrobials is similar to that recommended for cystitis in women except that nitrofurantoin is not considered a good choice. Treatment duration should generally be longer than that recommended for women.

The expanding role of fluoroquinolones

There has been a growing rate of resistance among common urinary tract pathogens, such as Escherichia coli, to traditional antimicrobial therapies including the "gold standard" trimethoprim-sulfamethoxazole (TMP-SMX). Consequently, fluoroquinolone antimicrobial agents have taken on an expanding management role for UTIs. In fact, the recent Infectious Diseases Society of America clinical management guidelines for UTI recommend fluoroquinolones as first-line therapy for uncomplicated UTI in areas where resistance is likely to be of concern. Fluoroquinolones have demonstrated high bacteriologic and clinical cure rates, as well as low rates of resistance, among most common uropathogens. There are currently 7 fluoroquinolones with indications for UTI in the United States. However, only 3 are commonly used: levofloxacin, ciprofloxacin, and, to a lesser extent, gatifloxacin. Many of the fluoroquinolone agents have once-daily dosing regimens, enhancing patient adherence. In addition, levofloxacin and gatifloxacin have same-dose bioequivalency between their intravenous and oral formulations, allowing for "switch" or step-down therapy from parenteral to oral formulations of the same agent at the same dose. Fluoroquinolones are indicated for the management of acute uncomplicated UTIs, as well as complicated and severe UTI and pyelonephritis, in adults. They are the first-line treatment of acute uncomplicated cystitis in patients who cannot tolerate sulfonamides or TMP, who live in geographic areas with known resistance >10% to 20% to TMP-SMX, or who have risk factors for such resistance. Fluoroquinolone properties include a broad spectrum of coverage, low rates of resistance, and good safety profiles.

The expanding role of fluoroquinolones

There has been a growing rate of resistance among common urinary tract pathogens, such as Escherichia coli, to traditional antimicrobial therapies including the "gold standard" trimethoprim-sulfamethoxazole (TMP-SMX). Consequently, fluoroquinolone antimicrobial agents have taken on an expanding management role for UTIs. In fact, the recent Infectious Diseases Society of America clinical management guidelines for UTI recommend fluoroquinolones as first-line therapy for uncomplicated UTI in areas where resistance is likely to be of concern. Fluoroquinolones have demonstrated high bacteriologic and clinical cure rates, as well as low rates of resistance, among most common uropathogens. There are currently 7 fluoroquinolones with indications for UTI in the United States. However, only 3 are commonly used: levofloxacin, ciprofloxacin, and, to a lesser extent, gatifloxacin. Many of the fluoroquinolone agents have once-daily dosing regimens, enhancing patient adherence. In addition, levofloxacin and gatifloxacin have same-dose bioequivalency between their intravenous and oral formulations, allowing for "switch" or step-down therapy from parenteral to oral formulations of the same agent at the same dose. Fluoroquinolones are indicated for the management of acute uncomplicated UTIs, as well as complicated and severe UTI and pyelonephritis, in adults. They are the first-line treatment of acute uncomplicated cystitis in patients who cannot tolerate sulfonamides or TMP, who live in geographic areas with known resistance >10% to 20% to TMP-SMX, or who have risk factors for such resistance. Fluoroquinolone properties include a broad spectrum of coverage, low rates of resistance, and good safety profiles.

Integrating fluoroquinolones into the hospital formulary

With the increasing availability of new agents, selection of fluoroquinolones for formulary inclusion can be difficult. Appropriate evaluation of the important characteristics (pharmacokinetic and pharmacodynamic properties, antimicrobial activity, efficacy, tolerability, cost) of these agents should allow selection of the most cost-effective ones. Evidence from in vitro studies and clinical trials indicates differences exist among fluoroquinolones, especially in terms of activity against gram-positive, aerobic organisms. For selected clinical situations, it may be important to choose an agent that is available in both intravenous and oral formulations. Comparative drug costs, as well as costs associated with potential clinical failure and adverse events, should be evaluated carefully. Dosage regimens should be considered, as shorter durations of therapy and less frequent dose administration may lead to reduced labor costs and increased patient compliance, thereby improving effectiveness and economic efficiency.

Fluoroquinolone adverse effects and drug interactions

Extensive pharmacologic and clinical development of quinolone antimicrobial agents has resulted in improved antimicrobial activity, pharmacokinetic features, toxicity, and drug-drug interaction profiles. Nalidixic acid and other early quinolones had limited use due to poor pharmacokinetics, relatively narrow antimicrobial spectrum of activity, and frequent adverse effects. Beginning with the development of fluoroquinolones, such as norfloxacin and ciprofloxacin, in the 1980s, the agents assumed a greatly expanded clinical role because of their broad antimicrobial spectrum of action, improved pharmacokinetic properties, and more acceptable safety profile. Although the pharmacokinetics and efficacy of the drugs have improved significantly, a major area of continued emphasis is to further reduce the frequency and severity of adverse events and drug-drug interactions. Older agents such as ciprofloxacin and ofloxacin are still extensively prescribed, but the focus of this article is on the newer fluoroquinolones (levofloxacin and other drugs that have been approved or have been under investigation since approximately 1997).

Is more than one quinolone needed in clinical practice?

OBJECTIVE

To review clinical information on fluoroquinolone antimicrobials to distinguish between these agents and help define their place in clinical practice.

DATA SOURCES

Primary and review articles on fluoroquinolones available commercially in the US as of August 2000 were identified through MEDLINE (from 1993-August 2000) and secondary sources.

STUDY SELECTION AND DATA EXTRACTION

All pertinent, published, clinical trials for levofloxacin, moxifloxacin, and gatifloxacin were included. Minimal data were included for quinolones with restricted or limited uses, including trovafloxacin, sparfloxacin, enoxacin, and lomefloxacin. Due to the quantity of data on ciprofloxacin, only more recent or pivotal trials or articles summarizing data on specific infections were included. Relevant information was included if it was believed to assist in differentiating between the fluoroquinolones for infections for which these agents would most commonly be considered.

DATA SYNTHESIS

Fluoroquinolones are a potent class of intravenous and oral broad-spectrum antimicrobial agents used for treating a wide range of community-acquired and nosocomial infections. More than 10 quinolones have been approved for use; although some of these have been withdrawn from the market, numerous others are under investigation. It has become increasingly important to be able to differentiate between these agents.

CONCLUSIONS

Differences in safety, antimicrobial spectrum of activity, and resistance development support the selective use of various fluoroquinolones in differing clinical situations.

The new antibiotics

It is easy to become overwhelmed by the amount of information available on the new antibiotics and difficult to keep abreast of the appropriate indications for each of them. For most patients with community-acquired infections, the first-line agent is usually not one of the newer agents, but a standard regimen, or at times, no antibiotic at all. The development of resistance is likely to parallel the extent to which these agents are prescribed. They should be used only when standard treatment fails, when compliance with treatment is a real and serious issue, or when the patient has a real allergic reaction to the standard regimen.

Development of a rapid PCR assay specific for Staphylococcus saprophyticus and application to direct detection from urine samples

Staphylococcus saprophyticus is one of the most frequently encountered microorganisms associated with acute urinary tract infections (UTIs) in young, sexually active female outpatients. Conventional identification methods based on biochemical characteristics can efficiently identify S. saprophyticus, but the rapidities of these methods need to be improved. Rapid and direct identification of this bacterium from urine samples would be useful to improve time required for the diagnosis of S. saprophyticus infections in the clinical microbiology laboratory. We have developed a PCR-based assay for the specific detection of S. saprophyticus. An arbitrarily primed PCR amplification product of 380 bp specific for S. saprophyticus was sequenced and used to design a set of S. saprophyticus-specific PCR amplification primers. The PCR assay was specific for S. saprophyticus when tested with DNA from 49 gram-positive and 31 gram-negative bacterial species. This assay was also able to amplify efficiently DNA from all 60 strains of S. saprophyticus from various origins tested. This assay was adapted for direct detection from urine samples. The sensitivity levels achieved with urine samples was 19 CFU with 30 cycles of amplification and 0.5 CFU with 40 cycles of amplification. This PCR assay for the specific detection of S. saprophyticus is simple and rapid (approximately 90 min, including the time for urine specimen preparation).

The safety profile of the fluoroquinolones

BACKGROUND

Premarketing trials showed the fluoroquinolone agents to have a favorable side-effect profile, with treatment-related adverse events comprising gastrointestinal, central nervous system, and dermatologic effects that were generally mild and reversible on cessation of treatment. However, postmarketing surveillance studies have identified severe adverse events, including severe anaphylaxis, QTc-interval prolongation, and potential cardiotoxicity, associated with 3 quinolone agents that either resulted in the removal of the agent from the market (temafloxacin and grepafloxacin) or significantly restricted its use due to substantial mortality and morbidity associated with liver toxicity (trovafloxacin). To date, there have been no such significant adverse events associated with the older fluoroquinolone agents, including ciprofloxacin, ofloxacin, norfloxacin, and levofloxacin. However, there are fewer data from postmarketing surveillance studies on the most recently approved agents, such as moxifloxacin and gatifloxacin, or agents awaiting approval, such as gemifloxacin.

OBJECTIVE

This paper examines safety data from the premarketing trials and postmarketing surveillance studies of fluoroquinolones available in the United States.

METHODS

A MEDLINE search was performed to identify all English-language studies published since 1980 concerning the safety profiles of the fluoroquinolones.

CONCLUSIONS

The fluoroquinolone antibacterial agents offer broad-spectrum therapy in patients with a variety of infections. Given similar spectra of activity, the choice between quinolones may be based on differences in efficacy and safety or tolerability profiles. Most drug reactions involving these agents are minor and reversible on discontinuing treatment, but adverse effects can be associated with significant mortality and morbidity, as was seen in the case of trovafloxacin and temafloxacin.

Comparison of the in vitro activity of and pathogen responses to sparfloxacin with those of other agents in the treatment of respiratory tract, urinary tract, and skin and skin-structure infections

The in vitro activity of and pathogen responses to sparfloxacin were compared with those of standard therapies for the treatment of patients with community-acquired pneumonia, complicated skin or skin-structure infections, urinary tract infections, acute bacterial exacerbations of chronic bronchitis, and acute maxillary sinusitis in 7 multicenter controlled trials in North America. Sparfloxacin was administered orally as a 400-mg loading dose followed by 200 mg once daily for up to 10 days. The bacteriologic efficacy of sparfloxacin (84% to 95%) was comparable to that of comparator drugs (77% to 100%). Sparfloxacin was generally 2 to 8 times more active (minimum inhibitory concentration for 90% of strains tested [MIC90]: 0.03 to 0.5 microg/mL) than comparators against common pathogens isolated in community-acquired infections, especially Streptococcus pneumoniae, including penicillin-resistant strains; Moraxella catarrhalis; Haemophilus influenzae; Streptococcus pyogenes; and Staphylococcus aureus. Sparfloxacin was also effective against Chlamydia and Mycoplasma species. The emergence of resistance was uncommon during sparfloxacin therapy (0.3% of 1100 cases). Higher area under the plasma concentration-time curve/MIC and maximum plasma concentration/MIC ratios for sparfloxacin were associated with clinical and bacteriologic efficacy, whereas lower ratios were associated with clinical and bacteriologic failure. The clinical efficacy of sparfloxacin (80% to 95%) was comparable to that obtained with the comparator drugs (71% to 92%). In addition, sparfloxacin was well tolerated and had an overall frequency of related adverse events similar to that of the comparators. There was a higher frequency of photosensitivity reactions but a lower level of digestive adverse events with sparfloxacin compared with comparators. Sparfloxacin is a suitable therapeutic alternative for the empiric treatment of respiratory tract infections owing to its favorable pharmacokinetic profile and activity against typical and atypical respiratory tract pathogens, even in geographic areas with a high incidence of penicillin resistance.

Sparfloxacin versus ciprofloxacin for the treatment of community-acquired, complicated skin and skin-structure infections

Fluoroquinolones have been shown to be effective in the treatment of complicated skin and skin-structure infections, in part because of their broad-spectrum antibacterial activity against causative pathogens that are resistant to older antimicrobial agents. We enrolled 603 adult patients (>58% male, >85% white) in a double-masked, double-dummy, randomized, multicenter trial to compare the efficacy and tolerability of sparfloxacin (400-mg loading dose followed by 200 mg once daily) with those of ciprofloxacin (750 mg twice daily) for 10 days in the treatment of community-acquired, complicated skin and skin-structure infections. The primary efficacy variable was clinical response, based on assessment of signs and symptoms, in the clinically assessable population. Patients in the sparfloxacin and ciprofloxacin groups were comparable with respect to demographic characteristics, underlying diseases, medical history, and laboratory test results. Wound infection was the most common diagnosis, and Staphylococcus aureus was the most frequently isolated pathogen. For the 475 clinically assessable patients, the clinical success rate (percentage of patients cured or improved) was 90.1% (210/233) with sparfloxacin and 87.2% (211/242) with ciprofloxacin. In this analysis (95% confidence interval [CI], -2.8 to 8.6) and the intent-to-treat analyses (95% CI, -4.2 to 6.2), results with sparfloxacin were statistically equivalent to those with ciprofloxacin (95% CI, -1 to 15.3). For bacteriologically assessable patients, eradication rates were 87.0% (141/162) with sparfloxacin and 79.9% (123/154) with ciprofloxacin (95% CI, -1 to 15.3). Eradication rates of S. aureus and coagulase-negative staphylococcal infections were 90.2% (101/112) with sparfloxacin and 77.9% (88/113) with ciprofloxacin. For patients with 2 or more pathogens at baseline (mixed infections), bacteriologic success was 87.6% for sparfloxacin and 77.9% for ciprofloxacin. Pseudomonas aeruginosa infections were eradicated or presumed eradicated in 71.4% (10/14) of sparfloxacin-treated patients and 87.5% (7/8) of ciprofloxacin-treated patients. Overall success rates in the bacteriologically assessable patients for sparfloxacin (84.6% [137/162]) and ciprofloxacin (78.6% [121/154]) were statistically equivalent (95% CI, -2.5 to 14.5). Tolerability was assessed in all patients who received study medication. The overall frequency of treatment-related adverse events was comparable in the 2 treatment groups (26.5% sparfloxacin, 23.3% ciprofloxacin). Drug-related adverse events involving the digestive system occurred in 7.1% of sparfloxacin-treated patients and 19.0% of ciprofloxacin-treated patients; photosensitivity reactions were reported in 11.1% of patients in the sparfloxacin group and 0.7% of patients in the ciprofloxacin group (P < 0.001). The mean change in QTc interval from baseline to the maximum on-treatment value was greater in the sparfloxacin group (9 milliseconds) than in the ciprofloxacin group (3 milliseconds) (P = 0.005; 95% CI, 0.002 to 0.010). The efficacy of sparfloxacin was comparable to that of ciprofloxacin in the treatment of community-acquired, complicated skin and skin-structure infections, including those caused by staphylococci, the most common pathogens. Sparfloxacin's once-daily regimen, high skin-tissue penetration, and improved activity against gram-positive cocci make it a therapeutic alternative to ciprofloxacin for patients who are not at risk for photosensitivity reactions or adverse events associated with prolongation of the QTc interval.