Efficacy Of Ciprofloxacin Research Articles

Clinical efficacy of ciprofloxacin in patients with respiratory tract infection refractory to penicillin or cephem: carbapenem-controlled clinical study

Clinical efficacy of ciprofloxacin in patients with respiratory tract infection refractory to penicillin or cephem: carbapenem-controlled clinical study

Liposome delivery of ciprofloxacin against intracellular Francisella tularensis infection

The effect of liposome delivery on the controlled release and therapeutic efficacy of ciprofloxacin against intracellular Francisella tularensis infection in vivo was evaluated in this study. Ciprofloxacin was encapsulated in small unilamellar vesicles by a remote loading procedure using an ammonium sulfate gradient. This procedure produced uniform sized liposomes (100 nm) with an entrapment rate of 90±3.5%. Following administration of unencapsulated or liposome-encapsulated ciprofloxacin by intravenous injection or aerosol inhalation, levels of ciprofloxacin in sera, lungs, liver and spleen were determined using 14C-ciprofloxacin as radiotracer for ciprofloxacin. Intravenous injection of liposome-encapsulated ciprofloxacin resulted in higher serum levels of drug in serum, as well as increased drug retention in lungs, liver and spleen, compared to that of free encapsulated drug. Aerosol administration of liposome-encapsulated ciprofloxacin by jet nebulization resulted in significantly higher drug levels and prolonged drug retention in the lower respiratory tract compared to the free drug. Aerosol inhalation of liposome-encapsulated ciprofloxacin, given either prophylactically or therapeutically, provided complete protection to mice against a pulmonary lethal infection model of F. tularensis. In contrast, ciprofloxacin given in its free form, was ineffective. These results suggest that liposome encapsulation of ciprofloxacin enhances drug delivery to the primary site of infection and results in increasing therapeutic efficacy against F. tularensis.

Significance of low-level resistance to ciprofloxacin in Klebsiella pneumoniae and the effect of increased dosage of ciprofloxacin in vivo using the rat granuloma pouch model.

This study was designed to compare the killing effect of ciprofloxacin on strains of Klebsiella pneumoniae with different MICs of ciprofloxacin in vivo using the rat granuloma pouch infection model. Five different strains were used: one ciprofloxacin-susceptible strain (MIC 0.06 mg/L); one strain highly resistant to ciprofloxacin (MIC 8 mg/L); and three nalidixic acid-resistant strains with low-level resistance to ciprofloxacin (MIC 0.25-0.5 mg/L). The efficacy of ciprofloxacin was evaluated 3 h after bacterial challenge (treating an acute infection) or after 3 days (treating a late infection) with a single intraperitoneal injection of ciprofloxacin (40 and 200 mg/kg). Ciprofloxacin was bactericidal against both growing K. pneumoniae (acute infection model) and non-growing K. pneumoniae (late infection model), but the extent of killing was significantly higher on growing bacteria and against ciprofloxacin-susceptible K. pneumoniae. A peak concentration of ciprofloxacin, at the infection site, <3 x MIC was not sufficient for optimal bacterial elimination. However, it was possible to compensate for the lower killing in low-level ciprofloxacin-resistant K. pneumoniae by increasing the dosage of ciprofloxacin from 40 to 200 mg/kg, consistent with the higher MIC.

Improved efficacy of ciprofloxacin administered in polyethylene glycol-coated liposomes for treatment of Klebsiella pneumoniae pneumonia in rats.

Animal and clinical data show that high ratios of the area under the concentration-time curve and the peak concentration in blood to the MIC of fluoroquinolones for a given pathogen are associated with a favorable outcome. The present study investigated whether improvement of the therapeutic potential of ciprofloxacin could be achieved by encapsulation in polyethylene glycol (PEG)-coated long-circulating sustained-release liposomes. In a rat model of unilateral Klebsiella pneumoniae pneumonia (MIC = 0.1 microg/ml), antibiotic was administered at 12- or 24-h intervals at twofold-increasing doses. A treatment period of 3 days was started 24 h after inoculation of the left lung, when the bacterial count had increased 1,000-fold and some rats had positive blood cultures. The infection was fatal within 5 days in untreated rats. Administration of ciprofloxacin in the liposomal form resulted in delayed ciprofloxacin clearance and increased and prolonged ciprofloxacin concentrations in blood and tissues. The ED(50) (dosage that results in 50% survival) of liposomal ciprofloxacin was 3.3 mg/kg of body weight/day given once daily, and that of free ciprofloxacin was 18.9 mg/kg/day once daily or 5.1 mg/kg/day twice daily. The ED(90) of liposomal ciprofloxacin was 15.0 mg/kg/day once daily compared with 36.0 mg/kg/day twice daily for free ciprofloxacin; 90% survival could not be achieved with free ciprofloxacin given once daily. In summary, the therapeutic efficacy of liposomal ciprofloxacin was superior to that of ciprofloxacin in the free form. PEG-coated liposomal ciprofloxacin was well tolerated in relatively high doses, permitting once daily administration with relatively low ciprofloxacin clearance and without compromising therapeutic efficacy.

Gonorrhea Showing Resistance to Quinolones

Surveillance of antibiotic sensitivity is crucial to effective treatment of infectious diseases. The authors of this NIH- and industry-funded study evaluated the efficacy of ciprofloxacin and cefixime in female sex workers in the Philippines. One hundred five …

A retrospective analysis of pharmacokinetic/pharmacodynamic indices as indicators of the clinical efficacy of ciprofloxacin

A retrospective analysis of the relationship between estimated pharmacokinetic/pharmacodynamic indices and the reported efficacy of ciprofloxacin has been carried out using different correlation models. f1.gif" BORDER="0">, T(ss) > MIC, f2.gif" BORDER="0"> and AUIC(ss) were calculated for each clinical case included in the study, from simulated plasma level curves corresponding to the dosage regimen administered. A univariate correlation analysis was performed considering efficacy (%) as the dependent variable and indices as the independent variables according to linear and non-linear pharmacokinetic-pharmacodynamic models (PK-PD models). The results prove that log-transformation of the independent variable improves the data fitting to linear model. The four estimated indices show a log-linear relationship with outcome, T(ss) > MIC and AUIC(ss) being the parameters best correlated with percentage efficacy. The E(max) model with intrinsic response is an additional correlation strategy for T(ss) > MIC, leading to estimated values of E(max) and E(0) of 100.34 +/- 25.09% and 24.40 +/- 11.7%, respectively. The wide range of bacteria responsible for the infections considered, including Gram-positive pathogens such as staphylococci, might explain the good correlation between T(ss) > MIC and percentage efficacy found for ciprofloxacin in this study.

Oral ciprofloxacin as antibacterial prophylaxis after allogeneic bone marrow transplantation: a reappraisal.

The efficacy of ciprofloxacin as antibacterial prophylaxis for allogeneic bone marrow transplantation has been well documented, and it virtually eliminated bacteremias caused by gram-negative pathogens in early reports. Ciprofloxacin was therefore incorporated into the prophylactic antibiotic regimen during allogeneic bone marrow or peripheral blood stem cell transplantation at Veterans General Hospital, Kaohsiung from February 1997. In 12 consecutive patients receiving allogeneic bone marrow or peripheral blood stem cell transplantation, ciprofloxacin-resistant Escherichia coli bacteremia developed in three (25%). In addition to our data, increasing evidence suggests that the widespread use of a fluoroquinolone is associated with the emergence of resistant isolates as well as documented infections caused by these resistant strains. The incidence of Escherichia coli bacteremia in our transplant patients was 25%, which was similar to that in patients not receiving preventive therapy or in those receiving trimethoprim-sulfamethoxazole prophylaxis. The prophylactic efficacy of ciprofloxacin in allogeneic bone marrow transplant or peripheral blood stem cell transplant recipients should therefore be reassessed.

Efficacy of ciprofloxacin in urinary tract infections and risk factors for ciprofloxacin‐resistant infections

Objectives: The study was undertaken to assess the safety and efficacy of sequential intravenous and oral ciprofloxacin in the treatment of moderate‐to‐severe urinary tract infections (UTI), and to identify risk factors for acquiring UTI caused by ciprofloxacin‐resistant organisms. Materials and Methods: Using a prospective, open, single‐centre study design, hospitalized patients with a clinical diagnosis of moderately severe UTI were enrolled. After a minimum of 3 days of intravenous ciprofloxacin, patients were switched to oral therapy. Assessment for response and analysis of risk factors were performed at the end of therapy. Results: Between December 1996 and November 1997, a total of 66 patients met the criteria for efficacy evaluation. Among the 55 patients with ciprofloxacin‐sensitive organisms, 51 patients (93%) were cured. Persisting infection was noted in three patients (5%) and one patient (2%) was re‐infected with a ciprofloxacin‐resistant organism. Of the organisms isolated, 14 (19%) were resistant to ciprofloxacin. The presence of prostatic obstruction (odds ratio 6.02, 95% confidence interval (CI) 1.28–28.30, P = 0.02) and recurrent UTI (odds ratio 8.63, 95% CI 1.81–41.17, P = 0.007) were independently associated with infections caused by ciprofloxacin‐resistant organisms. Adverse events were reported in 5 patients (8%) but no premature discontinuation or mortality was documented. Conclusion: Sequential therapy with oral therapy after initial parenteral ciprofloxacin is safe and effective in the management of moderate‐to‐severe UTI in appropriately selected patients.

Influence of Sanguisorba officinalis, a mineral-rich plant drug, on the pharmacokinetics of ciprofloxacin in the rat.

The significance of an interaction between ciprofloxacin and Sanguisorba officinalis L. (SO), a mineral-rich herbal medicine, was evaluated in this study. Male Sprague-Dawley rats (220-250 g) receiving ciprofloxacin dosages of 20 mg/kg po were concomitantly dosed with an aqueous extract of SO (equivalent to 2 g/kg crude drug). Blood and urine samples were collected over 6 and 24 h, respectively, for the quantitation of ciprofloxacin by HPLC. The presence of SO reduced significantly (P < 0.05) the maximum plasma concentration, the area under the concentration-time curve and the urinary recovery of ciprofloxacin, by 94%, 78% and 79%, respectively, compared with rats receiving only ciprofloxacin. The presence of SO also caused an eight-fold and two-fold increase in drug distribution (Vd, lambda(z)/F) and terminal elimination half-life (t1/2, lambda(z)) from 30.8 L/kg and 1.96 h, respectively. Therefore, should the use of both agents be required, sufficient time should be allowed to ensure the efficacy of ciprofloxacin.

A controlled trial comparing ciprofloxacin with mesalazine for the treatment of active Crohn’s disease

OBJECTIVE: The aim of this randomized controlled study was to investigate the efficacy of ciprofloxacin compared with mesalazine in treating active Crohn’s disease. METHODS: Patients with a mild to moderate flare-up of Crohn’s disease (mean Crohn’s Disease Activity Index [CDAI]; 217; range, 160–305) were randomized to receive ciprofloxacin 1 g/day or Pentasa 4 g/day for 6 wk. Complete remission was defined at wk 6 as a CDAI ≤ 150 associated with a decrease (Δ) in CDAI > 75. Partial remission was defined as a CDAI ≤ 150 with 50 < Δ CDAI < 75 or a CDAI > 150 with Δ CDAI > 50 at wk 6. Group sequential procedure with triangular continuation regions was used to monitor the trial through the difference in complete remission rates, every 20 patients included. RESULTS: Inclusion of patients was stopped at the second step, i.e., after 40 inclusions, with the conclusion of no difference in complete remission rates between ciprofloxacin- and Pentasa-treated groups. Among the 18 patients taking ciprofloxacin, two decided to stop treatment during the trial and three were considered as treatment failures because of deterioration at wk 3. Among the 22 patients taking mesalazine, one patient was lost to follow-up and eight patients were considered as treatment failures. Complete remission was observed in 10 patients (56%) treated with ciprofloxacin and 12 patients (55%) treated with mesalazine and partial remission was observed in three and one patient, respectively. CONCLUSIONS: This study suggests that ciprofloxacin 1 g/day is as effective as mesalazine 4 g/day in treating mild to moderate flare-up of Crohn’s disease.

Effect of Oral Ciprofloxacin on Bacterial Flora of Perineum, Urethra, and Lower Urinary Tract in Men with Spinal Cord Injury

A study was performed in 25 men with spinal cord injuries undergoing intermittent catheterization whose urine had > 1Cf’ bacterial colonies/ml to determine efficacy of ciprofloxacin in eradicating susceptible organisms from urine, urethra, and perineum. Cultures were obtained prior to, during, and 5 to 7 days after administration of 500 mg twice daily for 10 days. Organisms in urine were also present in the urethra and/or perineum in 20 cases. Susceptible bacteria disappeared from urine in all subjects; but at follow-up 12 had cultures positive for ciprofloxacin-resistant Gram-positive cocci, including 1 with methicillin-resistant Staphylococcus aureus (MRSA), and 2 with ciprofloxacin-resistant Acinetobacter sp. Treatment significantly reduced Gram-negative bacilli in perinea and urethras, but ciprofloxacin-susceptible organisms were replaced by resistant staphylococci, including MRSA, enterococci, and Acinetobacter sp. We support use of ciprofloxacin for treatment of urinary tract infections in persons with spinal cord injury, but in view of supercolonization with resistant organisms, the drug should be reserved for symptomatic persons not likely to respond to other oral agents.

The Efficacy of Topical Ciprofloxacin in the Treatment of Chronic Suppurative Otitis Media

We conducted a test of the efficacy of ciprofloxacin eardrops in 80 patients (95 ears) with otorrhea due to chronic suppurative otitis media in two treatment settings. One group (n = 40; 47 ears) received daily ciprofloxacin therapy plus aspiration in the clinic. The other group (n = 40; 48 ears) self-administered ciprofloxacin at home. Overall, otorrhea resolved in 88% of all ears within 12 days of the initiation of treatment. The clinic-treated patients tended to respond more rapidly than did the self-treated patients, but there was no statistically significant difference in success rates between the two groups. Side effects were negligible. We conclude that empiric topical ciprofloxacin therapy is an effective, safe and relatively inexpensive treatment for otorrhea in patients with chronic otitis media.

Ciprofloxacin-loaded polyisobutylcyanoacrylate nanoparticles: pharmacokinetics and in vitro antimicrobial activity

The disposition of ciprofloxacin in free form and loaded PIBCA/NP has been studied after intravenous infusion to the rabbit. Data from plasma concentration profiles revealed that pharmacokinetic parameters of ciprofloxacin associated with the colloidal carrier were greatly modified. Thus, ciprofloxacin-loaded PIBCA/NP led to increased AUC, t 1/2 and V d, and to a decreased Cl as compared with drug in solution. This could be due not only to the colloidal drug carrier but also to the pharmacokinetics of ciprofloxacin itself. Studies of efficacy against Mycobacterium avium complex in human macrophages proved that ciprofloxacin-loaded PIBCA/NP was more effective than free drug. The cytotoxicity of the polymeric material was observed at concentrations higher than 80 μg of PIBCA per ml with drastic reduction of viable macrophages. This may explain why the efficacy of ciprofloxacin associated with nanoparticles was much lower than expected.

The efficacy of ciprofloxacin and doxycycline against experimental tularaemia.

The efficacy of doxycycline and ciprofloxacin against an experimental tularaemia infection was assessed by comparing the median lethal dose (MLD) of Francisella tularensis Schu4 biotype A strain given intraperitoneally to antibiotic-treated and untreated mice. In untreated Porton outbred mice this was <1 cfu. Ciprofloxacin and doxycycline given at 40 mg/kg bd, initiated 48 h before infection and continued for 5 days after infection, afforded protection against intraperitoneal challenges of 3.7 x 10(6) cfu and 6.0 x 10(6) cfu, respectively. Protection was reduced when both antibiotics were given over a similar period at a lower dose regimen (20 mg/kg bd) to 8.8 x 10(5) cfu and 3.5 x 10(2) cfu, respectively. The greater reduction in protection offered by doxycycline was a reflection of the higher in-vitro MIC. Protection also decreased when the antibiotics were initiated 24 h after challenge. The MLD was 3.2 x 10(5) cfu and 1.6 x 10(6) cfu for ciprofloxacin and doxycycline respectively given at 40 mg/kg bd and was reduced further using the lower dose regimen. Overall, 90% of the deaths occurred following the withdrawal of antibiotic, irrespective of the antibiotic dose or type. It was possible to prevent this relapse by extending the antibiotic administration to 10 days after challenge. Ciprofloxacin and doxycycline may be useful for treating tularaemia, although the possibility of relapse should be considered.

Efficacy of doxycycline and ciprofloxacin against experimental Yersinia pestis infection.

The efficacies of ciprofloxacin and doxycycline prophylaxis and therapy were assessed against experimental pneumonic plague infections induced by two strains of Yersinia pestis in a mouse model. When exposed to an aerosol of Y. pestis strain GB, containing 8.39 x 10(5) +/- 4.17 x 10(4) cfu, the retained dose was 7.3 x 10(3) +/- 2.3 x 10(3) cfu. When exposed to an aerosol of Y. pestis strain CO-92, containing 1.86 x 10(5) +/- 7.4 x 10(3) cfu, the retained dose was 3.4 x 10(4) +/- 2.6 x 10(3) cfu. Both strains resulted in a respiratory and systemic infection closely resembling human pneumonic plague. Ciprofloxacin prophylaxis and therapy was successful against both strains for up to 24 h after challenge, but not after 48 h. Both doxycycline prophylaxis and therapy regimens were ineffective against both strains, although strain CO-92 was more susceptible in vitro to doxycycline than strain GB and supra-MIC levels were achieved in the serum and lungs of the animal.

Efficacy of ciprofloxacin and clarithromycin in acute bacterial exacerbations of complicated chronic bronchitis: interim analysis

In a multicenter, community-based study involving more than 300 primary care physicians in the United States, the efficacy and safety of ciprofloxacin and clarithromycin were compared in the treatment of patients with complicated or severe acute bacterial exacerbations of chronic bronchitis (ie, those who had failed previous antibiotic treatment within the prior 2 to 4 weeks; those with susceptibility data suggestive of a resistant pathogen; those having three or more acute exacerbations of chronic bronchitis [AECB] within the past year; and those having three or more comorbid conditions). Patients were randomized to either ciprofloxacin (CIP) 750 mg BID or clarithromycin (CLR) 500 mg BID, both administered for 10 days; all patients were treated on an outpatient basis. Clinical response at the end of therapy was the primary efficacy variable. An interim analysis was performed on the results from 743 patients (369 CIP, 374 CLR) with clinical and bacteriologic evidence of a broncho-pulmonary infection who had completed an ongoing study as of the end of May 1997. Three hundred nine pathogens were isolated before therapy, including Haemophilus spp (75 isolates), Moraxella catarrhalis (67 isolates), Staphylococcus aureus (55 isolates), and Streptococcus pneumoniae (23 isolates). Seven hundred eighteen patients (97%) were included in the efficacy-valid population. Clinical success at the end of therapy was observed in 90% (272 of 302) and 88% (274 of 313) of efficacy-valid patients treated with CIP and CLR, respectively (95% confidence interval [CI] = −2.4 to 7.6). Corresponding rates for the intent-to-treat population were also 90% (283 of 314) and 88% (281 of 321), respectively (95% CI = −2.3 to 7.5). The bacteriologic response for efficacy-valid patients at the end of therapy was 98% (119 of 122) for CIP-treated and 93% (103 of 111) for CLR-treated patients (95% CI = −0.8 to 10.2). The eradication rates for the three most commonly isolated gram-negative pathogens were 100% for CIP-treated and 95% for CLR-treated patients and 96% each for the two most commonly isolated gram-positive organisms. Superinfections due to respiratory tract pathogens were more common in the CLR group (10 organisms) than in the CIP group (4 organisms). Seventy-four (20%) CIP-treated and 62 (17%) CLR-treated patients reported 118 and 103 respective study-emergent adverse events. Headache, abdominal pain, diarrhea, nausea, and vomiting in CIP-treated patients and diarrhea, nausea, vomiting, and taste perversion in CLR-treated patients were the most commonly reported adverse events. Treatment of patients with complicated or severe AECB with CIP 750 mg BID was associated with rates of clinical success and bacteriologic eradication similar to those with CLR.

Ciprofloxacin and imipenem alone or in combination in experimental aortic valve endocarditis due to a ciprofloxacin borderline susceptible strain of Pseudomonas aeruginosa

The in vivo efficacies of ciprofloxacin, imipenem and their combination were studied in the rabbit left-sided endocarditis model by using a seroresistant strain of Pseudomonas aeruginosa with borderline susceptibilities to ciprofloxacin (MIC/MBC 1 2 and 2 8 μg/ml to ciprofloxacin and imipenem, respectively). Both antimicrobials expressed synergy in vitro at the MBC level. Ciprofloxacin was given intramuscularly, 20 mg/kg of body weight q 8 h and imipenem at the same regimen intravenously for 9 days. When compared to the controls no significant differences were observed among the applied regimens regarding (1) blood culture sterilization, (2) percent of sterile vegetation, and (3) mean bacterial titers in vegetations. No strain isolated from vegetations at the end of therapy had developed resistance to either ciprofloxacin or imipenem. It is concluded that further studies are required after appropriate increase of ciprofloxacin dosage and more frequent administration and/or even higher doses of imipenem.

Unorthodox antibiotic combinations including ciprofloxacin against high-level gentamicin resistant enterococci.

Development of high-level gentamicin resistance among enterococci represents a serious therapeutic problem as it precludes synergy between aminoglycosides and cell-wall active agents. As part of a search for active antibiotic combinations against enterococci with high-level gentamicin resistance, we tested by the time kill curve method the efficacy of ciprofloxacin combined with ampicillin, trimethoprim-sulphamethoxazole, vancomycin or teicoplanin against ten isolates of Enterococcus faecium, three of Enterococcus casseliflavus and 13 of Enterococcus faecalis that exhibited a MIC of gentamicin > or = 2000 mg/L. Most of the E. faecium were also resistant to ampicillin and to ciprofloxacin. The combination of ciprofloxacin with ampicillin was bactericidal against five of seven E. faecium strains that exhibited a ciprofloxacin MIC < or = 4 mg/L, but was inactive against the three E. faecium that were highly resistant to ciprofloxacin. This combination was also bactericidal against the E. casseliflavus and all the E. faecalis strains. The combination of ciprofloxacin with trimethoprim-sulphamethoxazole was bactericidal against five of the seven E. faecium and seven of the nine E. faecalis strains with a ciprofloxacin MIC < or = 4 mg/L. No bactericidal activity of this combination was seen against the enterococci that were highly resistant to either ciprofloxacin or to trimethoprim-sulphamethoxazole. The combination of ciprofloxacin with glycopeptides was inactive against E. faecium and E. casseliflavus and against E. faecalis, it was either ineffective or antagonistic; in only one case it was bactericidal. Five strains of E. faecium were resistant to all antibiotic combinations tested.

Critical influence of timing of administration of granulocyte colony-stimulating factor on antibacterial effect in experimental endocarditis due to Pseudomonas aeruginosa.

The effect of human recombinant granulocyte colony-stimulating factor (hrG-CSF) in rabbits with aortic endocarditis due to Pseudomonas aeruginosa was investigated. hrG-CSF significantly increased the number of polymorphonuclear neutrophils in blood and in cardiac vegetations and the expression of the adhesin molecule CD11b on the surface of polymorphonuclear neutrophils compared with those of animals that had not received hrG-CSF. When treatment was started 72 h after bacterial challenge, hrG-CSF alone had no antibacterial effect and did not enhance the efficacy of ciprofloxacin when used in combination, even with the higher dosing regimen used (50 micrograms/kg of body weight subcutaneously every 12 h for 4 days), in terms of number of positive blood cultures, bacterial counts in vegetations, and survival. In contrast, when treatment was started 30 min prior to bacterial challenge, hrG-CSF (50 micrograms/kg injected every 12 h) decreased bacterial titers in vegetations 72 h later (6.5 +/- 0.9 versus 7.9 +/- 0.9 log10 CFU/g of vegetation for hrG-CSF and controls, respectively; P = prophylactic administration of hrG-CSF did not increase the antibacterial effect of ciprofloxacin. We concluded that the antibacterial effect of hrG-CSF in experimental endocarditis was related to the timing of its administration since hrG-CSF demonstrated a significant but transient antimicrobial effect only when treatment was initiated before bacterial challenge.

Efficacy of Ciprofloxacin in Enteric Fever: Comparison of Treatment Duration in Sensitive and Multidrug-Resistant Salmonella

The efficacy of two regimens of ciprofloxacin was compared in a randomized study conducted on 69 patients with enteric fever, 52.2% of whom had infection with multidrug-resistant (MDR) strains of Salmonella typhi or S. paratyphi. Patients were randomly assigned to two regimens (10 days versus 14 days) of ciprofloxacin (500 mg twice a day). The mean +/- SD time required for defervescence was similar for both regimens (4.2 +/- 1.9 days in the 10-day group and 4.9 +/- 2.6 days in the 14-day group). A 100% cure was observed in each treatment group and no serious side effects were observed. Relapse occurred in two patients (14-day regimen). Only one patient (14-day regimen) had growth of S. typhi in stool culture at the time of the first follow-up three days after completion of therapy. Follow-up studies on available patients on two, six, and 12 months after completion of therapy revealed that all patients had negative stool cultures for S. typhi and S. paratyphi. This study indicates that ciprofloxacin may be recommended as an initial therapy for enteric fever for adult men and nonpregnant and nonlactating women in areas where MDR strains of S. typhi and S. paratyphi are prevalent, and that 500 mg twice a day of the drug given for 10 days is as effective as 14 days at the same dosage.