Treatment of bacillary dysentery: a comparison between enoxacin and nalidixic acid

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

Lomefloxacin versus trimethoprim/sulfamethoxazole in the treatment of adults with acute bacterial diarrhea

This study compared the efficacy and safety of lomefloxacin with that of trimethoprim/sulfamethoxazole (TMP/SMX) in the treatment of adult patients with acute diarrhea of bacterial etiology. Two centers enrolled a total of 133 patients; 99 (74%) presented with severe symptoms. The patients were randomized to receive either lomefloxacin 400 mg once daily (n=68) or TMP/SMX 160/800 mg twice daily (n=65) for five days. Bacteriologic success was achieved in 89.5% of evaluation lomefloxacin-treated patients and in 97.5% of patients treated with TMP/SMX. Clinical success was achieved in 100% and 97.5% of patients in the two treatment groups, respectively. The predominant organisms isolated in both groups at baseline, i.e. Shigella flexneri, Vibrio parahaemolyticus, and Salmonella Group D, were eradicated in all patients. Campylobacter jejuni was isolated at baseline in four patients in the lomefloxacin group but in none randomized to receive TMP/SMX; this organism persisted in three patients. Adverse events were experienced by 14 (23%) of the lomefloxacin-treated patients and by 18 (30%) of the TMP/SMX-treated patients. All adverse events reported were mild or moderate in severity and their distribution was similar in both groups. The results of this study show that lomefloxacin 400 mg once daily is as effective as TMP/SMX 160/800 mg twice daily and suggest that lomefloxacin is a promising new quinolone for the treatment of bacterial diarrhea.

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

Antibiotic therapy for Shigella dysentery

BACKGROUND

Shigella dysentery is a relatively common illness and occasionally causes death, worldwide. Mild symptoms are self-limiting but in more severe cases, antibiotics are recommended for cure and preventing relapse. The antibiotics recommended are diverse, have regional differences in sensitivity, and have side effects.

OBJECTIVES

To evaluate the efficacy and safety of antibiotics for treating Shigella dysentery.

SEARCH STRATEGY

In June 2009 we identified all relevant trials from the following databases: Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 4), MEDLINE, EMBASE, LILACS and the metaRegister of Controlled Trials (mRCT). We also checked conference proceedings for relevant abstracts, and contacted researchers, organizations, and pharmaceutical companies.

SELECTION CRITERIA

Randomized controlled trials of antibiotics for Shigella dysentery.

DATA COLLECTION AND ANALYSIS

Four authors, working in pairs, independently assessed trial eligibility, methodological quality, and extracted data. We calculated risk ratios (RR) with 95% confidence intervals (CI) for dichotomous data, and used the random-effects model for significant heterogeneity. We explored possible sources of heterogeneity, when present, in subgroup analyses of participant age and percentage of participants with confirmed Shigella infection.

MAIN RESULTS

Sixteen trials (1748 participants), spanning four decades and with differing sensitivity to Shigella isolates, met the inclusion criteria. Seven were judged to be at risk of bias due to inadequate allocation concealment or blinding, and 12 due to incomplete reporting of outcome data. Limited data from one three-armed trial of people with moderately severe illness suggest that antibiotics reduce the episodes of diarrhoea at follow-up (furazolidone versus no drug RR 0.21, 95% CI 0.09 to 0.48, 73 participants; cotrimoxazole versus no drug RR 0.30, 95% CI 0.15 to 0.59, 76 participants).There was insufficient evidence to consider any class of antibiotic superior in efficacy in treating Shigella dysentery, but heterogeneity for some comparisons limits confidence in the results. All the antibiotics studied were safe. There was inadequate evidence regarding the role of antibiotics in preventing relapses.

AUTHORS' CONCLUSIONS

Antibiotics reduce the duration of Shigella dysentery.Regularly updated local or regional antibiotic sensitivity patterns to different species and strains of Shigella are required to guide empiric therapy. More trials adhering to standard guidelines are required to evaluate the role of antibiotics in the treatment of severe forms of Shigella dysentery and in groups who are at high risk of complications.

Spectrophotometric determination of enoxacin as ion-pairs with bromophenol blue and bromocresol purple in bulk and pharmaceutical dosage form

Three simple, accurate and sensitive spectrophotometric methods were developed for determination of enoxacin. The methods based on extraction of this drug into chloroform as ion pairs with sulphonphthalein dyes as bromophenol blue and bromocresol purple. The optimum conditions of the reactions were studied and optimized. The absorbance of yellow products was measured at 412 nm for enoxacin-bromophenol blue and 410 nm for enoxacin-bromocresol purple. Linearity ranges were found to be 2.0-20.0 microg ml(-1) for enoxacin-bromophenol blue and 0.77-17.62 microg ml(-1) for enoxacin-bromocresol purple. The detection limits were found to be 0.084 microg ml(-1) and 0.193 microg ml(-1) for enoxacin-bromophenol blue and enoxacin-bromocresol purple, respectively. The composition of the ion pairs was found 1:1 by Job's method. The developed methods were applied successfully for the determination of this drug in pharmaceutical preparation. The data obtained by developed methods were compared with the spectrophotometric method in literature. No differences were found statistically.

In vitro antimicrobial susceptibility testing of bacterial enteropathogens causing traveler's diarrhea in four geographic regions

The emergence of resistant enteropathogens has been reported worldwide. Few data are available on the contemporary in vitro activities of commonly used antimicrobial agents against enteropathogens causing traveler's diarrhea (TD). The susceptibility patterns of antimicrobial agents currently available or under evaluation against pathogens causing TD in four different areas of the world were evaluated. Pathogens were identified in stool samples from U.S., Canadian, or European adults (18 years of age or older) with TD during 1997, visiting India, Mexico, Jamaica, or Kenya. MICs of 11different antimicrobials were determined against 284 bacterial enteropathogens by the agar dilution method. Ciprofloxacin, levofloxacin, ceftriaxone, and azithromycin were highly active in vitro against the enteropathogens, while traditional antimicrobials such as ampicillin, trimethoprim, and trimethoprim/sulfamethoxazole showed high levels and high frequencies of resistance. Rifaximin, a promising and poorly absorbable drug, had an MIC at which 90% of the strains tested were inhibited of 32 microg/ml, 250 times lower than the concentration of this drug in the stools. Amdinocillin, nalidixic acid, and doxycycline showed moderate activity. Fluoroquinolones are still the drugs of choice for TD in most regions of the world, although our study has a limitation due to the lack of Escherichia coli samples from Kenya and possible bias in selection of the patients for evaluation. Azithromycin and rifaximin should be considered as promising new agents. The widespread in vitro resistance of the traditional antimicrobial agents reported since the 1980s and the new finding of resistance to fluoroquinolones in Southeast Asia are the main reasons for monitoring carefully the antimicrobial susceptibility patterns worldwide and for developing and evaluating new antimicrobial agents for the treatment of TD.

Use of ciprofloxacin in developing countries

BACKGROUND

The demographic and subsequent economic pressures in developing nations have contributed to the increasing levels of antibiotic resistance among both commensal flora and pathogenic bacteria. As empirical options are diminishing daily, the role of ciprofloxacin in pediatric infections is becoming increasingly significant.

OBJECTIVE

The levels of resistance among various enteric pathogens are described, and the efficacy and safety of ciprofloxacin in treating infections such as shigellosis, cholera and Escherichia coli gastroenteritis are discussed. The findings of a large study of invasive salmonellosis in children in rural Africa are briefly presented, including the role of ciprofloxacin in multiresistant invasive disease. In addition the role of ciprofloxacin as a chemoprophylactic agent in the control of meningococcal disease is discussed.

RESULTS

The efficacy and safety of ciprofloxacin in children were found to be similar to those observed in adults for gastrointestinal infectious diseases. Overall the data presented confirm that ciprofloxacin is a safe and efficacious agent for use in children in the developing world.

CONCLUSION

Ciprofloxacin has been shown to be safe and efficacious in children in developing countries. Subsequently a priority for both the pharmaceutical industry and regulatory authorities in developing nations is to prevent fluoroquinolone misuse and development of antibiotic resistance.

Enoxacin: a reappraisal of its clinical efficacy in the treatment of genitourinary tract infections

Enoxacin is a 6-fluoronaphthyridinone antibacterial agent with good in vitro activity against Neisseria gonorrhoeae and most Gram-negative urinary tract pathogens. It is less active in vitro against Acinetobacter spp., Pseudomonas aeruginosa, and most Gram-positive bacteria, than against Gram-negative organisms. Enoxacin is rapidly absorbed, with a high oral bioavailability (87 to 91%). Of the absorbed dose, 44 to 56% is excreted unchanged in the urine, with peak urinary concentrations (>500 mg/L within 4 hours) remaining high (>100 mg/L) for up to 24 hours, sufficient to inhibit most urinary tract pathogens. Single (400 mg) and multiple oral dose regimens (100 to 600 mg twice or 3 times daily for 5 to 14 days) of enoxacin are as effective for the treatment of patients with complicated or uncomplicated urinary tract infections as other antibacterial agents such as amoxicillin, cefuroxime axetil, cotrimoxazole (trimethoprim-sulfamethoxazole) or trimethoprim. Noncomparative data suggest that enoxacin is also an effective agent for the treatment of prostatitis. Single 400 mgoral doses of enoxacin produce >/- 95% bacteriological cure rates in gonococcal infections, comparable to those produced by single intramuscular doses of ceftriaxone 250 mg. Perioperative doses of oral enoxacin 200 mg provide effective prophylaxis against postoperative bacteriuria after transurethral resection of the prostate. Concomitant administration of enoxacin with a number of commonly used therapeutic agents (e.g. antacids, methylxanthines, warfarin) affects the pharmacokinetic properties of either enoxacin or the coadministered agents. Enoxacin is reasonably well tolerated, with the incidence of adverse experiences ranging from 0 to 24%. Adverse events are mainly gastrointestinal, neurological or dermatological and resolve with minimal intervention. Overall, although enoxacin exhibits a number of clinical characteristics that are similar to those of other agents for the treatment of genitourinary tract infections, the advantages offered by this agent generally do not outweigh those of alternative fluoroquinolone agents. Thus, it is likely to prove to be yet another addition to the list of agents available for the management of these infections.

The new quinolones in the treatment of diarrhoea and typhoid fever

Diarrhoea and typhoid fever are two important diseases in the developing world, particularly the Asian countries. The management of these conditions is becoming increasingly difficult in the face of emerging pathogen resistance. The new fluoroquinolones demonstrate good in vitro activity against the causative pathogens involved, including those that are multidrug resistant. These agents have been shown to be very effective in the treatment of diarrhoea and typhoid in clinical trials, achieving results equal to, or better than, standard drugs. Importantly, fluoroquinolones also considerably shorten the duration of illness, thereby offering rapid relief to the patient.

Antimicrobial resistance of Shigella isolates causing traveler's diarrhea

Shigella isolates were identified as a cause of traveler's diarrhea in 67 (10%) of 675 patients and were tested for resistance to seven antimicrobial agents in a comparative study with those causing nontraveler's diarrhea in Spain. Ampicillin and chloramphenicol resistance was more frequent in Shigella flexneri (60 and 46%, respectively) than in Shigella sonnei (32 and 18%, respectively) and in travel-related isolates (P < 0.05 and 0.04, respectively). Of S. sonnei isolates from patients with traveler's diarrhea, 73 and 54% showed tetracycline and trimethoprim-sulfamethoxazole resistance, respectively, compared with only 8% of isolates from patients without a history of travel to developing countries (P < 0.007 and P < 0.0002). Low-level resistance to cephalosporins was found, whereas quinolone-resistant strains were not detected among travel-related Shigella isolates. Thus, quinolones may be an effective alternative therapy for travel-related shigellosis.

Quinolones in the treatment of acute bacterial diarrhoeal diseases

Acute bacterial diarrhoea is still an important disease, especially in developing countries. Resistance to antibiotics among enteric pathogens is relatively common in many parts of the world. The quinolones are active in vitro against these organisms, and achieve high stool concentrations. Because of these features, quinolones have been used in the treatment of acute diarrhoeal diseases caused by various bacteria. They appear to be effective in the therapy of shigellosis and travellers' diarrhoea, as well as in the prevention of diarrhoeal disease in travellers. However, their role in the treatment of salmonella gastroenteritis has not been established yet.

Comparative efficacy of ceftriaxone and ampicillin for treatment of severe shigellosis in children

In a prospective randomized open study, ceftriaxone, 50 mg/kg per day, was compared with ampicillin, 100 mg/kg per day, both given for a period of 5 days, for the treatment of 40 children whose mean (+/- SD) age was 4.5 +/- 3.2 years and who had severe dysentery caused by Shigella organisms. Twenty patients were treated with ceftriaxone and 20 with ampicillin. Both drugs were initially given intravenously for a period of 1 to 2 days and were continued intramuscularly, in the case of ceftriaxone, or orally, in the patients receiving ampicillin. All Shigella organisms isolated were susceptible to ceftriaxone; 28% were resistant to ampicillin. The diarrhea persisted for a mean (+/- SD) period of 2.5 +/- 1.0 days in the ceftriaxone-treated patients versus 6.8 +/- 6.3 days in the ampicillin-treated patients (p less than 0.005). At the end of the 5 days of therapy, stool cultures for Shigella organisms were negative in 12 (60%) of the 20 patients from the ampicillin group and in all the children (100%) from the ceftriaxone group (p less than 0.001). Bacteriologic relapses were observed in eight (40%) of the patients treated with ampicillin but in none of the children treated with ceftriaxone (p less than 0.001). In instances of clinical or bacteriologic failure in the ampicillin group, retreatment was instituted in most of the cases with ceftriaxone; persistent clearing of the Shigella organisms from the stool was finally achieved after a mean (+/- SD) period of 11.75 +/- 9.4 days after therapy was started, as compared with 1.85 +/- 0.6 days in the ceftriaxone-treated patients (p less than 0.001). We conclude that in children with severe shigellosis, treatment with ceftriaxone for 5 days is effective and better than use of ampicillin for clinical cure and eradication of the Shigella organisms from the stool.

Quinolones and the gastrointestinal tract

A number of studies have evaluated the efficacy of the new fluoroquinolones for therapy of bacterial enteric diseases and for prevention of gram-negative sepsis in granulocytopenic patients. The success of the quinolones in these settings is related to several special features of these agents, including their spectrum of activity and high fecal levels, which are in turn reflected in their effect on the gastrointestinal flora. Other factors that are important, particularly for invasive disease such as typhoid fever and shigellosis, include good intracellular and bowel wall penetration, and lymph node and systemic drug concentrations many times higher than the MICs of the causative organisms. This article reviews the factors that contribute to the changes in fecal flora, and the results of clinical studies in patients with diarrhea, granulocytopenic patients, and patients with selected other infections of, or related to, the gastrointestinal tract.

Fluoroquinolone antimicrobial agents

The fluoroquinolones, a new class of potent orally absorbed antimicrobial agents, are reviewed, considering structure, mechanisms of action and resistance, spectrum, variables affecting activity in vitro, pharmacokinetic properties, clinical efficacy, emergence of resistance, and tolerability. The primary bacterial target is the enzyme deoxyribonucleic acid gyrase. Bacterial resistance occurs by chromosomal mutations altering deoxyribonucleic acid gyrase and decreasing drug permeation. The drugs are bactericidal and potent in vitro against members of the family Enterobacteriaceae, Haemophilus spp., and Neisseria spp., have good activity against Pseudomonas aeruginosa and staphylococci, and (with several exceptions) are less potent against streptococci and have fair to poor activity against anaerobic species. Potency in vitro decreases in the presence of low pH, magnesium ions, or urine but is little affected by different media, increased inoculum, or serum. The effects of the drugs in combination with a beta-lactam or aminoglycoside are often additive, occasionally synergistic, and rarely antagonistic. The agents are orally absorbed, require at most twice-daily dosing, and achieve high concentrations in urine, feces, and kidney and good concentrations in lung, bone, prostate, and other tissues. The drugs are efficacious in treatment of a variety of bacterial infections, including uncomplicated and complicated urinary tract infections, bacterial gastroenteritis, and gonorrhea, and show promise for therapy of prostatitis, respiratory tract infections, osteomyelitis, and cutaneous infections, particularly when caused by aerobic gram-negative bacilli. Fluoroquinolones have also proved to be efficacious for prophylaxis against travelers' diarrhea and infection with gram-negative bacilli in neutropenic patients. The drugs are effective in eliminating carriage of Neisseria meningitidis. Patient tolerability appears acceptable, with gastrointestinal or central nervous system toxicities occurring most commonly, but only rarely necessitating discontinuance of therapy. In 17 of 18 prospective, randomized, double-blind comparisons with another agent or placebo, fluoroquinolones were tolerated as well as or better than the comparison regimen. Bacterial resistance has been uncommonly documented but occurs, most notably with P. aeruginosa and Staphylococcus aureus and occasionally other species for which the therapeutic ratio is less favorable. Fluoroquinolones offer an efficacious, well-tolerated, and cost-effective alternative to parenteral therapies of selected infections.

Therapy for shigellosis. I. Randomized, double-blind trial of nalidixic acid in childhood shigellosis

We compared nalidixic acid, 55 mg/kg/day, with ampicillin, 100 mg/kg/day, both given orally for 5 days, in the treatment of children with dysentery caused by shigellosis. All patients entered into the study had illness of less than 72 hours' duration and no prior allopathic drug therapy. Treatment was randomized and administered in double-blind fashion. Patients initially treated with ampicillin who were infected with a Shigella strain resistant to ampicillin were considered as a separate group (ampicillin-R). All isolates were susceptible to nalidixic acid. Similar percentages of patients treated with nalidixic acid (26/32, 81%) and with ampicillin (17/22, 77%) were clinically cured by the end of therapy; the rate in ampicillin-R (3/14, 21%) patients was significantly lower (p less than 0.001). Stool frequency in patients treated with nalidixic acid was significantly less than for ampicillin-treated or ampicillin-R patients during the final 3 study days. All patients treated with nalidixic acid and ampicillin had Shigella eradicated from their stool by day 3, compared with 77% (10/13) of ampicillin-R patients (p less than 0.05, ampicillin-R vs nalidixic acid or ampicillin). We conclude that nalidixic acid is an effective alternative to ampicillin in the treatment of shigellosis caused by nalidixic acid-susceptible strains.