Single-dose ciprofloxacin at 100 versus 250 mg for treatment of uncomplicated urinary tract infections in women

Efficacy and safety of quinolones for the treatment of uncomplicated urinary tract infections in women: a network meta-analysis

INTRODUCTION AND HYPOTHESIS

Uncomplicated urinary tract infection (uUTI) is defined as the presence of pathogenic organisms in the urinary tract without anatomical and functional abnormalities, is accompanied by inflammatory leukocytes and cytokines and may or may not develop clinical symptoms. The frequency of uncomplicated urinary tract infection is higher in young women. Several quinolone treatment regimens are available; however, since we do not know which is the best antibiotic regimen for the treatment of this urinary infection, we analyzed the published evidence and conducted a systematic review with network meta-analysis. The aim was to compare and hierarchize quinolones according to their efficacy and safety and to identify the best treatment for uncomplicated urinary tract infection in women through a systematic review with network meta-analysis.

METHODS

Medline, Embase, LILACS, Cochrane CENTRAL and other databases were searched for trials. Bias in the trials was assessed using the Cochrane Collaboration tool. To analyze efficacy and adverse events, for direct comparisons, we obtained risk ratios and 95% confidence intervals by applying a fixed-effects model using tau² and Q² tests to calculate the heterogeneity. For the network meta-analysis, we analyzed the indirect comparisons by Bucher's method.

RESULTS

We included 18 trials (8765 women). For premenopausal women, ofloxacin had a 57% probability of achieving remission but an 83% frequency of adverse events. For postmenopausal women, ofloxacin was 82% more effective for remission, with a 49% frequency of adverse events, compared with other types of quinolones.

CONCLUSIONS

Compared with other quinolones, ofloxacin 200 mg once daily for a treatment duration < 3 days provides the highest clinical and bacteriological remission rates with the lowest relapse and resistance rates for the treatment of women with uUTIs. However, additional trials are needed to confirm our findings, especially when the treatment duration exceeds 3 days.

Managing recurrent urinary tract infections in women

Recurrent urinary infections are a common problem for women of all ages. Risk factors for urinary infection differ for pre- and postmenopausal women. Management strategies are well established, and include treatment of the acute symptomatic episode, and decreasing the frequency of subsequent episodes. This update focuses on the management of acute uncomplicated urinary infection, the most common bacterial infection in women.

Do high doses of quinolones decrease the emergence of antibacterial resistance? A systematic review of data from comparative clinical trials

OBJECTIVE

To evaluate whether the use of high doses of quinolones may reduce the development of antimicrobial resistance.

DATA SOURCES

Relevant studies were identified from PubMed and the Cochrane Central Register of Controlled Trials (until June 2006).

STUDY SELECTION AND DATA EXTRACTION

We performed a systematic review of the available data from comparative clinical studies reporting on the emergence of resistance when using different daily doses of quinolones.

DATA SYNTHESIS

Twelve studies reported comparative data regarding the emergence of antimicrobial resistance. Development of resistance occurred in patients of 5/12 studies included in the review, with no statistical difference between the compared arms.

CONCLUSIONS

Although data from laboratory studies are indicative of a benefit from using high daily doses of quinolones in order to minimize the emergence of antimicrobial resistance, the data from the reviewed trials are limited and can neither support nor reject this finding. However, it seems that if a true benefit exists this is rather small and regards mainly isolates with initially high minimum inhibitory concentrations. Further comparative clinical studies focusing on this issue are justified.

Uncomplicated urinary tract infection in women. Current practice and the effect of antibiotic resistance on empiric treatment

OBJECTIVE

To review treatment recommendations for empiric therapy of uncomplicated urinary tract infection (uUTI) in light of evolving antibiotic resistance and to consider use of guidelines to promote optimal practice.

QUALITY OF EVIDENCE

PubMed was searched and additional relevant references were identified by reviewing articles found in the search. Guidelines were identified through discussion with family practitioners. Level of evidence was assessed for recommendations.

MAIN MESSAGE

Many women have uUTIs. The treatment approach is usually empiric antimicrobial therapy without obtaining pretherapy cultures. Trimethoprim-sulfamethoxazole is standard first-line empiric treatment. While resistance to this drug is increasing, it remains only about 10% in community-acquired Escherichia coli in Canada. Concerns about increased resistance have contributed to greater use of fluoroquinolones, but widespread empiric use of this class of medications might promote resistance to fluoroquinolones. Hence, fluoroquinolones should not be considered first-line therapy. While guidelines for treatment of uUTIs have been developed, their usefulness is compromised by their conflicting recommendations.

CONCLUSION

Trimethoprim-sulfamethoxazole and nitrofurantoin remain first-choice empiric therapy for uUTIs. Development of guidelines relevant to family physicians and community education programs that incorporate local susceptibility patterns are important strategies for promoting optimal practice.

Best pharmacological practice: urinary tract infections

Urinary tract infection is the most frequent bacterial infection. Acute uncomplicated urinary infection and acute non-obstructive pyelonephritis occur in young women with normal genitourinary tracts. Empirical short-course therapy is preferred for the management of acute cystitis, but evolving resistance requires continuing reassessment of optimal antimicrobial selection. Empirical trimethoprim or trimethoprim/sulfamethoxazole has been recommended, but increasing resistance to these agents suggests that pivmecillinam, nitrofurantoin and perhaps fosfomycin trometamol should be considered. Although flouroquinolones are effective as short-course therapy, widespread empirical use of these agents should be discouraged because of potential promotion of resistance. For acute non-obstructive pyelonephritis, flouroquinolones are the empirical oral treatment of choice, although urine culture results should direct continuing therapy. Complicated urinary tract infection occurs in men or women of all ages with underlying abnormalities of the genitourinary tract. Treatment of complicated urinary infection is individualised, taking into consideration the underlying abnormality and susceptibilities of the infecting organism. Asymptomatic bacteriuria should not be treated except in pregnant women, in patients prior to undergoing an invasive surgical procedure, or renal transplant recipients in the early postrenal transplant period.

Short-term therapy of acute uncomplicated cystitis

Short-term therapy, including single-dose treatment and up to 3-day courses, can be considered the treatment of choice in premenopausal women with acute uncomplicated cystitis, because of similar effectiveness, better tolerance and compliance, and lower cost as compared with conventional therapy. Several studies with trimethoprim alone or in combination with a sulfonamide, usually sulphamethoxazole, and with fluoroquinolones with moderately long half-lives, such as ciprofloxacin, enoxacin, lomefloxacin and ofloxacin, suggested that results obtained with a single dose may be inferior to those with a 3-day course, and therefore that the latter may be better. Longer therapy was not considered to be necessary. On the other hand, fluoroquinolones with longer half-lives, such as fleroxacin, pefloxacin and rufloxacin, as single-dose therapy may be as effective as other standard regimens. Fosfomycin trometamol may also be suitable for single-dose therapy. Agents that have not been shown effective in any of these short-term regimens should no longer be used for the treatment of acute cystitis.

Urinary pharmacodynamics of low-dose ciprofloxacin and ofloxacin

The incidence of resistant uropathogens to the fluoroquinolones is increasing, but their effectiveness in the urine against these strains is unknown. In this investigation, we studied the urinary pharmacodynamics of ciprofloxacin (100 mg) and ofloxacin (200 mg) against urinary isolates that were moderately resistant to ciprofloxacin (Escherichia coli, MIC = 4; Klebsiella pneumoniae, MIC = 4. Staphylococcus saprophyticus, MIC = 8) and ofloxacin. Seven healthy female volunteers received three doses (one dose every 12 h) of ciprofloxacin and ofloxacin in a randomized, crossover design with a 1-week washout period between regimens. Urine bactericidal activity was determined after the first and third dose of each drug. Both ciprofloxacin and ofloxacin exhibited prolonged (> or = 6 h) urine bactericidal activity against the E. coli and K. pneumoniae isolates after the first dose. No bactericidal activity was demonstrated for ciprofloxacin against the S. saprophyticus strain. In contrast, ofloxacin exhibited urine bactericidal activity for 8 h against this isolate. Similar findings were observed after the third dose, with the exception that ciprofloxacin exhibited a short period (4 h) of bactericidal activity against the S. saprophyticus strain. In summary, low-dose regimens of ciprofloxacin and ofloxacin exhibited prolonged bactericidal activity against moderately resistant strains of common bacterial uropathogens. Only ofloxacin demonstrated bactericidal activity in the urine during the first dosing interval against a moderately resistant isolate of S. saprophyticus.

Diagnosis and treatment of uncomplicated urinary tract infection

Acute uncomplicated urinary tract infection 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. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole seem to be more effective than those with beta lactams, regardless of the duration. Because of increasing resistance to trimethoprim-sulfamethoxazole, an alternative regimen such as nitrofurantoin (in a 7-day regimen), a fluoroquinolone, or an oral third-generation cephalosporin may be a better empiric choice in some areas. Acute pyelonephritis caused by highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, but 10- to 14-day regimens are recommended. We prefer to use antimicrobials that attain high renal tissue levels, such as a fluoroquinolone, trimethoprim-sulfamethoxazole, or an aminoglycoside, for pyelonephritis. Acute uncomplicated cystitis or pyelonephritis in healthy adult men is uncommon but is generally caused by the same spectrum of uropathogens with the same antimicrobial susceptibility profile as that seen in women.

Double-blind study comparing 3-day regimens of cefixime and ofloxacin in treatment of uncomplicated urinary tract infections in women

This double-blind randomized study compared 3-day regimens of cefixime (400 mg once daily) and ofloxacin (200 mg twice a day) in the treatment of urinary tract infections in women. The respective clinical cure rates for the two groups of women were 89 and 92% after 7 days and 81 and 84% after 4 weeks. The respective microbiological cure rates (free of bacteriuria) for the two groups of women were 83 and 86% after 7 days and 77 and 80% after 28 days. A 3-day cefixime regimen seems to be as efficient as a 3-day ofloxacin regimen in the treatment of uncomplicated cystitis in women.

Single dose quinolone treatment in acute uncomplicated urinary tract infection in women

A total of 125 ambulatory women (85 premenopausal and 40 postmenopausal) who experienced 174 acute urinary tract infections with mainly gram-negative bacteria (99%) was randomized to receive a single dose, 2-tablet treatment with either ofloxacin (400 mg.), norfloxacin (800 mg.) or ciprofloxacin (500 mg.). Cure was achieved in 163 of the 174 acute episodes (94%). More specifically, the cure rates were 97% (57 of 59 infections) with ofloxacin, 96.5% (56 of 58) with ciprofloxacin and 88% (50 of 57) with norfloxacin. While the initial cure rate of the acute urinary tract infections was 96% (112 of 117) in the premenopausal group, it reached only 90% (51 of 57) in the postmenopausal group. The 17 urinary tract infections that followed the initial 2-tablet quinolone treatment were cured by either an additional single dose, 2-tablet treatment with a different quinolone in 6 cases, a 1-day treatment with other adequate antibacterials in 9 and a 7-day treatment in 2. The 2-tablet quinolone treatment proved to be an effective, easy and cost-effective treatment for acute urinary tract infections in premenopausal and postmenopausal women.

Treatment of acute uncomplicated urinary tract infections with 3 days of lomefloxacin compared with treatment with 3 days of norfloxacin

The bacteriologic and clinical efficacies of 3 days of lomefloxacin therapy were compared with those of 3 days of norfloxacin therapy for the treatment of acute uncomplicated urinary tract infections in a prospective, randomized, double-blind study. One hundred sixty-four subjects were enrolled at five Canadian centers; 84 received lomefloxacin, and 80 received norfloxacin. Escherichia coli (84%) and Staphylococcus saprophyticus (11%) were the most common organisms isolated. Forty subjects (24%) had low quantitative counts in their pretherapy urine specimens. In the intent-to-treat analysis, 76 lomefloxacin subjects (91%) and 76 norfloxacin subjects (95%) were cured or improved at follow-up 5 to 9 days posttreatment and 73 (87%) and 71 (89%) subjects from the lomefloxacin and norfloxacin groups, respectively, were cured or improved at 4 to 6 weeks posttreatment. Bacteriologic eradication occurred in 61 of 63 lomefloxacin subjects (97%) with > or = 10(8) CFU/liter in their pretherapy specimens and 56 of 59 norfloxacin subjects (95%) at 5 to 9 days and 55 (87%) and 53 (90%) subjects from the lomefloxacin and norfloxacin groups, respectively, at 4 to 6 weeks. There were no statistically significant differences in outcome. Adverse effects which were potentially related to the study medications were reported by 26% of the subjects who received lomefloxacin and 25% of the subjects who received norfloxacin. There were no severe adverse events, and only one subject discontinued therapy. These data suggest that 3 days of therapy with either lomefloxacin or norfloxacin is effective in the treatment of acute uncomplicated urinary tract infections.

Standards of therapy for urinary tract infections in adults

Therapeutic standards have not been well defined for many forms of bacterial urinary tract infection. In women with uncomplicated infections, these exist for bacterial cystitis and for acute pyelonephritis. For most other categories of illness, among patients with complicated infections, no treatment regimens have been determined. As a result, well-designed clinical trials for these patient populations should be a priority.

Single-dose and three-day regimens of ofloxacin versus trimethoprim-sulfamethoxazole for acute cystitis in women

We compared the safety and efficacy of a single 400-mg dose of ofloxacin, ofloxacin (200 mg) once daily for 3 days, and trimethoprim-sulfamethoxazole (160:800 mg) twice daily for 7 days for the treatment of acute uncomplicated cystitis (urinary tract infection [UTI]) in women. At 5 weeks posttreatment, 35 (81%) of 43 patients treated with single-dose ofloxacin, 40 (89%) of 45 treated with 3 days of ofloxacin, and 41 (98%) of 42 treated with trimethoprim-sulfamethoxazole were cured (P = 0.03, single-dose ofloxacin group versus trimethoprim-sulfamethoxazole group). Retreatment for symptomatic recurrent UTI was given to 7 (16%) of 43 patients initially treated with single-dose ofloxacin, 3 (7%) of 45 patients treated with 3 days of ofloxacin, and 0 of 42 patients treated with trimethoprim-sulfamethoxazole (P = 0.01, single-dose ofloxacin group versus trimethoprim-sulfamethoxazole group). There was a trend in each of the three treatment groups toward an association between persistent or recurrent episodes of significant bacteriuria and a history of UTI in the past year and with diaphragm use. Ofloxacin was more effective than trimethoprim-sulfamethoxazole in eradicating Escherichia coli from rectal cultures during or soon after therapy, but there were no differences at later follow-up visits. Adverse effects were equally common among the three treatment groups. We conclude that single-dose ofloxacin was less effective than 7 days of trimethoprim-sulfamethoxazole for treatment of uncomplicated cystitis in women, while the 3-day ofloxacin regimen and the trimethoprim-sulfamethoxazole regimen were not significantly different in efficacy.

Use of quinolones in treatment of prostatitis and lower urinary tract infections

The newer quinolones, ciprofloxacin, enoxacin, fleroxacin, lomefloxacin, norfloxacin, ofloxacin and pefloxacin are highly effective antimicrobial agents against the majority of bacteria responsible for urinary tract infections and bacterial prostatitis. The pharmacokinetic properties of these agents after oral administration result in high concentrations in human urine, as well as in prostatic fluid and prostatic tissue. Ciprofloxacin, enoxacin and lomefloxacin produce the highest concentrations in prostatic tissue, followed by norfloxacin, ofloxacin and fleroxacin. More than 400 patients with chronic bacterial prostatitis have been treated with one of the newer quinolones in varying doses for 10 to 84 days. The results indicate a cure rate of approximately 70%, although the follow-up period is quite variable in these studies. Clinical trials of short-term (single dose vs three days) therapy with the newer quinolones conducted in women with uncomplicated lower urinary tract infections were reviewed. Although bacteriologic cure rates were high with single doses of ciprofloxacin, fleroxacin, norfloxacin, ofloxacin and pefloxacin, approximately one in five women with suspected uncomplicated lower urinary tract infection experience failure of single-dose therapy. In contrast, a three-day regimen with these agents is more effective than a single-dose in the treatment of uncomplicated lower urinary tract infections in women.

Management of acute uncomplicated urinary tract infection in adults

Acute uncomplicated UTI is one of the most common problems for which young women seek medical attention, and it accounts for considerable morbidity and health care costs. Acute cystitis is a superficial infection of the bladder mucosa, whereas pyelonephritis involves tissue invasion of the upper urinary tract. Localization tests suggest that as many as one third of episodes of acute cystitis are associated with silent upper tract involvement. 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. Because of the superficial nature of cystitis, single-dose and 3-day regimens have gained wide acceptance as the preferred methods of treatment. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole appear to be more effective than those with beta-lactams, regardless of the duration. Acute pyelonephritis does not necessarily imply a complicated infection. Upper tract infection with highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, and 14-day regimens are often used. We prefer to use antimicrobials that attain high renal tissue levels, such as trimethoprim-sulfamethoxazole or quinolones, for pyelonephritis. Women with frequently recurring infections can be successfully managed by continuous prophylaxis, either daily or thrice-weekly, by postcoital prophylaxis, or, in compliant patients, by early self-administration of single-dose or 3-day therapy as soon as typical symptoms are noted. Our drug of choice for all these regimens is trimethoprim-sulfamethoxazole. Acute uncomplicated cystitis in adult men is very uncommon, but it is occasionally noted in homosexual men who practice insertive and intercourse or in heterosexual men whose partners have vaginal colonization with E. coli.

Comparative in vitro activities of sparfloxacin (CI-978; AT-4140) and other antimicrobial agents against staphylococci, enterococci, and respiratory tract pathogens

The in vitro activity of sparfloxacin (CI-978; AT-4140) was compared with those of other antimicrobial agents against isolates of staphylococci, enterococci, and various respiratory tract pathogens. Sparfloxacin was the most active drug tested against staphylococci (MIC for 90% of the strains tested [MIC90], 0.125 micrograms/ml) and enterococci (MIC90, 1.0 microgram/ml). It was also active against Haemophilus influenzae (MIC90, less than or equal to 0.06 microgram/ml), Moraxella (Branhamella) catarrhalis (MIC90, 0.125 microgram/ml), Streptococcus pneumoniae (MIC90, 0.5 microgram/ml), and Streptococcus pyogenes (MIC90, 1.0 microgram/ml).

Comparison of three dosage regimens of ciprofloxacin in urinary tract infections

Fifty-four patients with complicated UTI were administered ciprofloxacin in doses of 500 mg (30 subjects) and 250 mg (24 subjects) at 12-hour intervals. While a positive effect was noted in 96-100% upon termination of therapy, the effect was still present 3 weeks later in 90% of the high-dose, but only in 71% of the low-dose group. In 23 patients with uncomplicated UTI, a positive effect of the three-day therapy with 100 mg of ciprofloxacin at 12-hour intervals was observed in 91% of subjects. Intolerance to the agent was found in one case only. Development of resistance to ciprofloxacin was not observed.

Review of published studies on single dose therapy of urinary tract infections

The published studies of the use of single dose antimicrobial therapy for the treatment of urinary tract infection have been reviewed. In women and children a single dose of any of several antimicrobial agents was as effective as a course of treatment for uncomplicated urinary tract infections caused by Escherichia coli. Trimethoprim or co-trimoxazole are currently the preferred agents for single dose therapy. Failure of single dose therapy may prove to be a simple guide as to the need for further urinary tract investigation or more intensive therapy. Single dose antimicrobial therapy is now the treatment of choice for uncomplicated urinary tract infections.

Fosfomycin trometamol in a single dose versus norfloxacin for seven days in the treatment of uncomplicated urinary infections in general practice

The efficacy and tolerability of fosfomycin trometamol in a single dose of 3 g was compared with norfloxacin 400 mg b.i.d. for seven days in the treatment of adult female patients with uncomplicated urinary infections. 158 female patients with a mean age of 30 years who presented symptoms of dysuria and frequency with documented pyuria and bacteriuria on urinalysis (greater than or equal to 10(5) cfu/ml of urine) were initially included in the study. The total number of clinically and bacteriologically evaluable patients was 111, of which 61 received fosfomycin trometamol and 50 norfloxacin. One to two days after the double blind medication schedule for seven days, 55 of 60 patients (92%) in the fosfomycin trometamol group and 48 of 50 patients (96%) in the norfloxacin group were clinically cured. 37 patients without significant bacteriuria showed a clinical cure rate of over 90% in both therapy groups. Two to three days after the single dose treatment with fosfomycin trometamol the initial infecting pathogen was eradicated in 60 of the 61 patients (98%). One to two days after a seven day treatment with norfloxacin 48 of 50 patients (96%) showed an eradication of the initial infecting pathogen. Six weeks after the start of therapy 39/60 patients (65%) and 32/49 (65%) in the fosfomycin trometamol and norfloxacin groups respectively, remained free from urinary infection. The reinfection rate in both treatment groups was approximately 25%. The relapse rate in the post treatment evaluation period of four weeks was relatively low in both therapy groups, 5/49 patients (10%) in the norfloxacin group and 3/55 patients (6%) in the fosfomycin trometamol group, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Single-dose ciprofloxacin in the treatment of uncomplicated urinary tract infection in women

In a randomised, double-blind trial two single-dose regimens of ciprofloxacin were evaluated for treatment of acute urinary tract infection (UTI) in women. Fifty-three women received 250 mg and 46 750 mg of ciprofloxacin. Seven days after treatment the eradication rate was 81.1% and 82.6% in the low and high dose groups respectively; the clinical cure rate at 28 days was 64.1% and 73.9% respectively. In women with recurrent UTI a significantly better response was found with the high dose regimen (92% versus 68%; p less than 0.001). It is concluded that a single 250 mg dose of ciprofloxacin is effective for treatment in most women with acute UTI, but in women with recurrent infection a 750 mg dose is preferable.

Quinolone antibacterial agents for the treatment of genitourinary tract infections

The fluoroquinolones have expanded the therapeutic options available for the treatment of genitourinary tract infections. Their ease of oral administration, favourable pharmacokinetics, low incidence of adverse reactions, and broad spectrum of in vitro activity against aerobic and facultative organisms make them especially suitable for treating bacteriuria, particularly when pathogens are resistant to other available oral agents. Their efficacy has also been established in the treatment of prostatis, gonorrhea and chancroid. They have lower in vitro activity against chlamydia, ureaplasma and anaerobes, and their role in the treatment of non-gonococcal urethritis, vaginitis and acute pelvic inflammatory disease is less well established.

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.

Ofloxacin versus trimethoprim-sulfamethoxazole for treatment of acute cystitis

We compared the safety and efficacies of ofloxacin and trimethoprim-sulfamethoxazole for the treatment of acute uncomplicated cystitis in women enrolled in a multicenter study. Data from three centers were combined for this report because the study design and study populations were identical, and patients were enrolled within an 18-month period. Cure rates for evaluable patients 4 weeks after treatment were high for all regimens: ofloxacin (200 mg) twice daily for 3 days, 22 of 25 (88%) cured; ofloxacin (200 mg) twice daily for 7 days, 42 of 49 (86%) cured; ofloxacin (300 mg) twice daily for 7 days, 25 of 25 (100%) cured; and trimethoprim-sulfamethoxazole (160/800 mg) twice daily for 7 days, 46 of 52 (88%) cured. Ofloxacin was more effective than trimethoprim-sulfamethoxazole in eradicating Escherichia coli from rectal cultures during and 1 week after treatment. Both ofloxacin and trimethoprim-sulfamethoxazole markedly reduced vaginal colonization with E. coli during and 4 weeks after therapy. Emergence of resistant coliforms in rectal flora was found in 5 (19%) of 27 patients treated with trimethoprim-sulfamethoxazole but none of 50 ofloxacin-treated patients who were studied (P = 0.004). Adverse effects were equally common among the four treatment groups. We conclude that 3 to 7 days of ofloxacin is as safe and effective as trimethoprim-sulfamethoxazole for treatment of uncomplicated cystitis in women and that ofloxacin effectively reduces the fecal and vaginal reservoirs of coliforms in such patients.

Quinolones in urology

The new quinolones have broad antimicrobial spectra covering all aerobic gram-negative and gram-positive bacteria encountered in urinary tract infections. All are administered orally, some also parenterally, low degree of resistance, few side effects and bacteriological and clinical cure rates similar to or higher than traditional antimicrobials make them especially suitable for treatment of complicated urinary tract infections including bacterial prostatitis. Non-critical use of quinolones in simple infections where standard drugs may be equally effective and safe should be discouraged.

Ciprofloxacin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use

Ciprofloxacin is one of a new generation of fluorinated quinolones structurally related to nalidixic acid. The primary mechanism of action of ciprofloxacin is inhibition of bacterial DNA gyrase. It is a broad spectrum antibacterial drug to which most Gram-negative bacteria are highly susceptible in vitro and many Gram-positive bacteria are susceptible or moderately susceptible. Unlike most broad spectrum antibacterial drugs, ciprofloxacin is effective after oral or intravenous administration. Ciprofloxacin has been most extensively studied following oral administration. It attains concentrations in most tissues and body fluids which are at least equivalent to the minimum inhibitory concentration designated as the breakpoint for bacterial susceptibility in vitro. The results of clinical trials with orally and intravenously administered ciprofloxacin have confirmed the potential for its use in a wide range of infections, which was suggested by its in vitro antibacterial and pharmacokinetic profiles. It has proven an effective treatment for many types of systemic infections as well as for both acute and chronic infections of the urinary tract. Ciprofloxacin generally appeared to be at least as effective as alternative orally administered antibacterial drugs in the indications in which they were compared, and in some indications, to parenterally administered antibacterial therapy. However, further studies are needed to fully clarify the comparative efficacy of ciprofloxacin and standard antibacterial therapies. Bacterial resistance to ciprofloxacin develops infrequently, both in vitro and clinically, except in the setting of pseudomonal respiratory tract infections in cystic fibrosis patients. The drug is also well tolerated. Thus, as an orally active, broad spectrum and potent antibacterial drug, ciprofloxacin offers a valuable alternative to broad spectrum parenterally administered antibacterial drugs for use in a wide range of clinical infections, including difficult infections due to multiresistant pathogens.

Ciprofloxacin in management of urinary tract infection

Ciprofloxacin is a new quinolone derivative which is particularly well adapted for the treatment of bacterial urinary tract infection. Virtually all uropathogens are susceptible, and the development of resistance is uncommon. Its pharmacokinetic characteristics reveal that effective concentrations of the drug are easily achieved with twice a day oral therapy in the blood, urine, kidneys, and prostate--even in advanced renal failure. The drug is well tolerated, even with prolonged courses of therapy. It will be particularly useful in the treatment of antibiotic-resistant, complicated, and/or prostatic infection.

Ciprofloxacin: chemistry, mechanism of action, resistance, antimicrobial spectrum, pharmacokinetics, clinical trials, and adverse reactions

Ciprofloxacin, considered a benchmark when comparing new fluoroquinolones, shares with these agents a common mechanism of action: inhibition of DNA gyrase. While ciprofloxacin demonstrated a fairly good activity against gram-positive bacteria, it is against gram-negative organisms that it proved to be more potent than other fluoroquinolones. It is the most active quinolone against Pseudomonas aeruginosa, with MIC90s on the order of 0.5 micrograms/ml. When given orally, ciprofloxacin exhibited 70% bioavailability and attained peak serum levels ranging between 1.5 and 2.9 micrograms/ml after a single 500-mg dose. Nineteen percent of an oral dose was excreted as metabolites in both urine and feces. In most cases, body fluids and tissue concentrations equaled or exceeded those in concurrent serum samples. In clinical trials, oral and intravenous ciprofloxacin yielded similar clinical and bacteriologic results compared to standard therapy in a wide array of systemic infections, including lower and upper urinary tract infections; gonococcal urethritis; skin, skin structure, and bone infections; and respiratory tract and gastrointestinal tract infections. Major benefits with the oral form of this quinolone are expected in chronic pyelonephritis and bone infections, and in pulmonary exacerbations in patients with cystic fibrosis. Emergence of ciprofloxacin-resistant microorganisms has been noted in clinical practice, primarily Pseudomonas aeruginosa and Staphylococcus aureus. The most frequent side effects are related to the gastrointestinal tract; but attention should be given to adverse central nervous system effects.