The efficacy and safety of once-daily ceftibuten compared with co-amoxiclav in the treatment of acute bacterial sinusitis

Management of Acute and Chronic Sinusitis in Adult Patients

Sinusitis is a highly prevalent illness in the United States resulting in significant sinus discomfort and pain. Diagnoses of sinusitis are typically based on patients’clinical presentations but are complicated because numerous microbiologic etiologies exist (viruses, bacteria, fungi). Along with its diagnosis, sinusitis should be classified as acute or chronic on the basis of the duration of symptoms. It is important to differentiate acute from chronic sinusitis because their etiologies and treatments may differ. Patients who present with symptoms of acute sinusitis for at least 1 week after an acute viral illness are appropriate candidates for antibiotics. Antibiotic choices should be based on local resistance patterns and patients’ characteristics, but a 2-week course of first-line antibiotics (eg, amoxicillin, trimethoprim-sulfamethoxazole) is usually sufficient. Compared to that of acute sinusitis, the management of chronic bacterial sinusitis is more complicated and controversial. Chronic sinusitis may be medically or surgically managed. Medical therapy of chronic bacterial sinusitis should consist of a prolonged course of antibiotics (4 to 6 weeks). Broad-spectrum antibiotics should be used, covering Staphylococcus aureus, • -lactamase-producing organisms, and in certain situations anaerobes. Adjunctive therapy with saline nasal spray, nasal decongestants, and inhaled nasal corticosteroids may be helpful for certain patients with acute or chronic sinusitis.

WITHDRAWN: Antibiotics for acute maxillary sinusitis in adults

Currently, two separate Cochrane reviews, ‘Antibiotics for acute maxillary sinusitis in adults ’ and ‘Antibiotics for clinically diagnosed acute rhinosinusitis in adults ’ describe the effect of antibiotics for acute rhinosinusitis. Although both Cochrane reviews study the same condition, they look at different populations (patients in which the diagnosis was based on clinical signs and symptoms and patients in which the diagnosis was confirmed by imaging). Because of this, the conclusions are different in these Cochrane reviews. This was confusing for clinicians who needed to read both Cochrane reviews to know which conclusions are most applicable to their patients.
 
 This review is being withdrawn and will be incorporated into the updated publication of ‘Antibiotics for clinically diagnosed acute rhinosinusitis in adults ’. This ‘merged’ review will still maintain the relevant distinction between the two populations. However, information on the effectiveness of antibiotics for rhinosinusitis will be published in the ‘merged’ Cochrane review. We will omit the comparison between antibiotics (as published in this Cochrane review) because the choice for certain antibiotics and/or doses differs according to the local antibiotic resistance patterns and therefore this comparison is less relevant.

The editorial group responsible for this previously published document have withdrawn it from publication.

Antibiotics for acute maxillary sinusitis in adults

BACKGROUND

Sinusitis is one of the most common diagnoses among adults in ambulatory care, accounting for 15% to 21% of all adult outpatient antibiotic prescriptions. However, the role of antibiotics for sinusitis is controversial.

OBJECTIVES

To assess the effects of antibiotics in adults with acute maxillary sinusitis by comparing antibiotics with placebo, antibiotics from different classes and the side effects of different treatments.

SEARCH METHODS

We searched CENTRAL 2013, Issue 2, MEDLINE (1946 to March week 3, 2013), EMBASE (1974 to March 2013), SIGLE (OpenSIGLE, later OpenGrey (accessed 15 January 2013)), reference lists of the identified trials and systematic reviews of placebo-controlled studies. We also searched for ongoing trials via ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP). We imposed no language or publication restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antibiotics with placebo or antibiotics from different classes for acute maxillary sinusitis in adults. We included trials with clinically diagnosed acute sinusitis, confirmed or not by imaging or bacterial culture.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results, extracted data and assessed trial quality. We calculated risk ratios (RRs) for differences between intervention and control groups in whether the treatment failed or not. All measures are presented with 95% confidence intervals (CIs). We conducted the meta-analyses using either the fixed-effect or random-effects model. In meta-analyses of the placebo-controlled studies, we combined data across antibiotic classes. Primary outcomes were clinical failure rates at 7 to 15 days and 16 to 60 days follow-up. We used GRADEpro to assess the quality of the evidence.

MAIN RESULTS

We included 63 studies in this updated review; nine placebo-controlled studies involving 1915 participants (seven of the studies clearly conducted in primary care settings) and 54 studies comparing different classes of antibiotics (10 different comparisons). Five studies at low risk of bias comparing penicillin or amoxicillin to placebo provided information on the main outcome: clinical failure rate at 7 to 15 days follow-up, defined as a lack of full recovery or improvement, for participants with symptoms lasting at least seven days. In these studies antibiotics decreased the risk of clinical failure (pooled RR of 0.66, 95% CI 0.47 to 0.94, 1084 participants randomised, 1058 evaluated, moderate quality evidence). However, the clinical benefit was small. Cure or improvement rates were high in both the placebo group (86%) and the antibiotic group (91%) in these five studies. When clinical failure was defined as a lack of full recovery (n = five studies), results were similar: antibiotics decreased the risk of failure (pooled RR of 0.73, 95% CI 0.63 to 0.85, high quality evidence) at 7 to 15 days follow-up.Adverse effects in seven of the nine placebo-controlled studies (comparing penicillin, amoxicillin, azithromycin or moxicillin to placebo) were more common in antibiotic than in placebo groups (median of difference between groups 10.5%, range 2% to 23%). However, drop-outs due to adverse effects were rare in both groups: 1.5% in antibiotic groups and 1% in control groups.In the 10 head-to-head comparisons, none of the antibiotic preparations were superior to another. However, amoxicillin-clavulanate had significantly more drop-outs due to adverse effects than cephalosporins and macrolides.

AUTHORS' CONCLUSIONS

There is moderate evidence that antibiotics provide a small benefit for clinical outcomes in immunocompetent primary care patients with uncomplicated acute sinusitis. However, about 80% of participants treated without antibiotics improved within two weeks. Clinicians need to weigh the small benefits of antibiotic treatment against the potential for adverse effects at both the individual and general population levels.

Oral cephalosporins: current perspectives

Oral cephalosporins had been, for years, a small group of compounds belonging to the first or second-generation cephalosporins, with a limited antimicrobial spectrum. New oral first-generation cephalosporins include cefprozil and loracarbef, similar to cefadroxil and cefaclor, respectively, with activity similar to cefaclor but with pharmacokinetic improvements. Second-generation oral cephalosporins are esters of already available cephalosporins, and third-generation oral cephalosporins include a number of drugs whose activity is similar to available parenteral drugs, showing pharmacokinetic advantages and, some of them, better resistance to hydrolysis mediated by extended wide-spectrum beta-lactamases. They may be a good alternative against mild to moderate ENT infections, UTIs, STDs, lower respiratory tract and skin and soft tissue infections, mainly in the outpatient setting.

Antibiotics for acute maxillary sinusitis

BACKGROUND

Expert opinions vary on the appropriate role of antibiotics for sinusitis, one of the most commonly diagnosed conditions among adults in ambulatory care.

OBJECTIVES

We examined whether antibiotics are effective in treating acute sinusitis, and if so, which antibiotic classes are the most effective.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2007, Issue 3); MEDLINE (1950 to May 2007) and EMBASE (1974 to June 2007).

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing antibiotics with placebo or antibiotics from different classes for acute maxillary sinusitis in adults. We included trials with clinically diagnosed acute sinusitis, whether or not confirmed by radiography or bacterial culture.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened search results, extracted data and quality assessed trials. Risk ratios (RR) were calculated for differences in the intervention and control groups to see whether or not the treatment was a failure. In meta-analysing the placebo-controlled studies, the data across antibiotic classes were combined. Primary outcomes were the clinical failure rates at 7 to 15 days and 16 to 60 days follow up.

MAIN RESULTS

Fifty-seven studies were included in the review; six placebo-controlled studies and 51 studies comparing different classes of antibiotics. Five studies involving 631 participants provided data for comparison of antibiotics to placebo, when clinical failure was defined as a lack of cure or improvement at 7 to 15 days follow up. These studies found a slight statistical difference in favor of antibiotics, compared to placebo, with a pooled RR of 0.66 (95% confidence interval (CI) 0.44 to 0.98). However, the clinical significance of the result is equivocal, also considering that cure or improvement rate was high in both the placebo group (80%) and the antibiotic group (90%). Based on six studies, when clinical failure was defined as a lack of total cure, there was significant difference in favor of antibiotics compared to placebo with a pooled RR of 0.74 (95% CI 0.65 to 0.84) at 7 to 15 days follow up. None of the antibiotic preparations was superior to each other.

AUTHORS' CONCLUSIONS

Antibiotics have a small treatment effect in patients with uncomplicated acute sinusitis in a primary care setting with symptoms for more than seven days. However, 80% of participants treated without antibiotics improve within two weeks. Clinicians need to weigh the small benefits of antibiotic treatment against the potential for adverse effects at both the individual and general population level.

Antibiotics for acute maxillary sinusitis

BACKGROUND

For adults seeking care in ambulatory medical practices, sinusitis is the most common diagnosis treated with antibiotics.

OBJECTIVES

We examined whether antibiotics are indicated for acute sinusitis, and if so, which antibiotic classes are most effective.

SEARCH STRATEGY

Relevant studies were identified from searches of MEDLINE and EMBASE in December 2001, contacts with pharmaceutical companies and bibliographies of included studies.

SELECTION CRITERIA

Randomized trials were eligible that compared antibiotic to control or antibiotics from different classes, for acute maxillary sinusitis. Additional criteria for inclusion were diagnostic confirmation by radiograph or sinus aspiration, outcomes that included clinical cure or improvement, and a sample size of 30 or more adults. Of 2058 potentially relevant studies, two or more reviewers identified 49 studies meeting selection criteria.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two persons and synthesized descriptively. Some data were analyzed quantitatively using a random effects model. Primary outcomes were: a) clinical cure, and b) clinical cure or improvement. Secondary outcomes were radiographic improvement, relapse rates, and dropouts due to adverse effects.

MAIN RESULTS

Forty-nine trials, involving 13,660 participants, evaluated antibiotic treatment for acute maxillary sinusitis. Major comparisons were antibiotic versus control (n of 5); newer, non-penicillin antibiotic versus penicillin class (n of 10); and amoxicillin-clavulanate versus other extended spectrum antibiotics (n of 17), where n is the number of trials. Most trials were conducted in otolaryngology settings. Only 8 trials described adequate allocation and concealment procedures; 20 were double-blind. Compared to control, penicillin improved clinical cures [relative risk (RR) 1.72; 95% CI 1.00 to 2.96]. Treatment with amoxicillin did not significantly improve cure rates (RR 2.06; 95% CI 0.65 to 6.53) but there was significant variability between studies. Radiographic outcomes were improved by antibiotic treatment. Comparisons between classes of antibiotics showed no significant differences: newer non-penicillins versus penicillins (RR for cure 1.07; 95% CI 0.99 to 1.17); newer non-penicillins versus amoxicillin-clavulanate (RR for cure 1.03; 95% CI 0.96 to 1.11). Compared to amoxicillin-clavulanate, dropouts due to adverse effects were significantly lower for cephalosporin antibiotics (RR 0.47; 95% CI 0.30 to 0.73). Relapse rates within one month of successful therapy were 7.7%.

REVIEWER'S CONCLUSIONS

For acute maxillary sinusitis confirmed radiographically or by aspiration, current evidence is limited but supports the use of penicillin or amoxicillin for 7 to 14 days. Clinicians should weigh the moderate benefits of antibiotic treatment against the potential for adverse effects.

Rigid nasal endoscopy versus sinus puncture and aspiration for microbiologic documentation of acute bacterial maxillary sinusitis

Sinus puncture and aspiration is an invasive procedure that hinders patient enrollment in studies of acute bacterial maxillary sinusitis (ABMS). Pain and minor bleeding also limit its potential diagnostic utility in clinical practice. Cultures obtained by rigid nasal endoscopy were compared with those from sinus puncture and aspiration in 53 patients with ABMS; 46 patients were assessable. Considering recovery of Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae from puncture and aspiration as the gold standard, endoscopy cultures demonstrated a sensitivity of 85.7% (95% confidence interval, 56.2-97.5), specificity of 90.6% (73.8-97.5), positive predictive value of 80% (51.4-94.7), negative predictive value of 93.5% (77.2-98.9), and accuracy of 89.1% (75.6-95.9). Ten adverse events related to puncture and aspiration occurred in 5 (9.6%) of 52 patients; there were no endoscopy-related adverse events. In our study, the largest to date, endoscopic sampling compared favorably with puncture and aspiration for identifying H. influenzae, M. catarrhalis, and S. pneumoniae in ABMS and produced less morbidity.

Changes in fecal flora and comparative multiple-dose pharmacokinetics of ceftibuten, cefpodoxime proxetil and amoxycillin/clavulanate

OBJECTIVE: To investigate changes in fecal flora and multiple-dose pharmacokinetics with the oral antibiotics ceftibuten 400 mg daily and cefpodoxime proxetil (CPX) 200 mg every 12 h, compared to amoxycillin/clavulanate 500/125 mg every 8 h during and following 1 week of medication. METHODS: In an open randomized triple crossover design, 18 (nine female, nine male) healthy volunteers received each drug for 7 days, followed by a 'washout' period of 4 weeks. Serum and urine levels of the substances were determined by bioassay, and for ceftibuten isomers by high-pressure liquid chromatography. Statistical analysis of quantitative aerobic and anaerobic cultures of feces was performed, and beta-lactamase activity was determined. RESULTS: Ceftibuten showed a mean Cmax of 18.9 (SD 3.0) mg/L, a terminal half-life of 2.89 h, and an AUCtot of 100 (21.8) mg.h/L; protein binding was 63.7 (5.1)%, and accumulation was marginal. Cefpodoxime proxetil had a Cmax of 1.92 (0.61) mg/L, a terminal half-life of 1.97 (0.42) h and an AUCtot of 10.8 (3.3) mg.h/L; no accumulation was seen. Amoxycillin and clavulanate had Cmax values of 7.15 (2.16) mg/L and 3.39 (1.31) mg/L, terminal half-life values of 1.03 (0.15) h and 0.93 (0.17) h, AUCtot values of 20.0 (4.2) mg.h/L and 8.87 (3.10) mg.h/L, and there was no accumulation. Statistical analysis for ech microorganism in fecal samples showed significant differences between amoxycillin/clavulanate and the two third-generation cephalosporins, but virtually no differences between ceftibuten and cefpodoxime proxetil. Eleven of 12 volunteers reported loose stools (days 2-7, mean duration 4.4 (SD 2.7) days) with amoxycillin/clavulanate, but nobody during ceftibuten administration and one volunteer during cefpodoxime proxetil administration. CONCLUSIONS: Ceftibuten showed excellent and cefpodoxime favorable pharmacokinetic properties, with significantly less pronounced fecal flora changes and intestinal side effects compared to amoxycillin/clavulanate. The multiple crossover design allows powerful microbiological statistical analysis and pharmacokinetic parameter comparisons.

Treatment of acute sinusitis in childhood with ceftibuten

Acute sinusitis is a common childhood illness. If it is overlooked or undertreated, suppurative and intracranial complications may develop. Amoxicillin has traditionally been the antibiotic of choice for treatment of acute sinusitis. However, the efficacy of amoxicillin has been reduced because of the emergence of bacteria producing b-lactamase and altered penicillin-binding proteins. This study compares the effectiveness of 10, 15, and 20 days of ceftibuten therapy with 14 days of erythromycin-sulfisoxazole therapy in treating acute sinusitis. The results indicate that both treatment regimens are effective in treating acute sinusitis (96% clinical response for erythromycin-sulfisoxazole vs 92% for a 10- or 15-day course of ceftibuten vs 100% for a 20-day course of ceftibuten). Longer treatment periods may be more effective in resolving the acute illness.

Comparison of the effectiveness of levofloxacin and amoxicillin-clavulanate for the treatment of acute sinusitis in adults

In this comparative trial, outpatients with acute sinusitis were randomly assigned to receive levofloxacin (500 mg orally once daily) or amoxicillin-clavulanate (500/125 mg orally 3 times daily) for 10 to 14 days. The success rates (cured and improved) 2 to 5 days after the end of treatment were 88.4% for the 267 clinically evaluable patients who received levofloxacin and 87.3% for the 268 clinically evaluable patients who received amoxicillin-clavulanate. Drug-related adverse events occurred in a smaller percentage of patients in the levofloxacin treatment group (7.4%) than in the amoxicillin-clavulanate treatment group (21.2%). The most common of these were nausea, diarrhea, vaginitis, and abdominal pain for levofloxacin-treated patients and diarrhea, vaginitis, nausea, genital moniliasis, abdominal pain, vomiting, and flatulence for amoxicillin-clavulanate-treated patients. The results of this study show that once-daily administration of levofloxacin is as effective and better tolerated than amoxicillin-clavulanate administered 3 times daily for treating acute sinusitis in adult outpatients.

Efficacy and tolerability of cefprozil versus amoxicillin/clavulanate for the treatment of adults with severe sinusitis

Cefprozil is a beta-lactamase-stable oral cephalosporin with an antimicrobial spectrum that includes gram-positive and gram-negative pathogens commonly associated with acute bacterial sinusitis, one of the most common upper respiratory tract infections among adults. We conducted a multicenter, open-label study to compare the efficacy and safety of cefprozil and amoxicillin/clavulanate in the treatment of adults with severe acute bacterial sinusitis diagnosed by clinical and radiographic criteria. A total of 278 patients entered the study, 140 (59 males, 81 females) in the cefprozil group and 138 (69 males, 69 females) in the amoxicillin/clavulanate group. Patients were randomized to 10 days of treatment with either cefprozil 500 mg BID or amoxicillin/clavulanate 500 mg/125 mg TID. Clinical severity was assessed at study entry, and patients were stratified based on symptom grade. Efficacy was evaluated using a 10-point questionnaire administered during, at the end of, and 2 weeks after completing therapy. At the end of treatment, 84.5% (71/84) of patients with severe sinusitis treated with cefprozil had a satisfactory clinical response, which was not significantly different from the 89.9% (80/89) of patients in the amoxicillin/clavulanate group who had a satisfactory clinical response. Two weeks after completing treatment, 80.8% (63/78) of cefprozil-treated patients and 81.0% (64/79) of amoxicillin/clavulanate-treated patients with severe sinusitis had a satisfactory response. Relapse was more common among amoxicillin/clavulanate patients (6/70; 8.6%) than among cefprozil patients (2/65; 3.1%), but the difference was not statistically significant. Significantly more amoxicillin/clavulanate-treated patients experienced adverse events compared with cefprozil-treated patients (P < 0.001), including diarrhea (P < 0.001), nausea (P < 0.042), and rash (P < 0.035). Three times as many amoxicillin/clavulanate patients discontinued treatment because of adverse events. Cefprozil demonstrated comparable clinical efficacy to amoxicillin/clavulanate in the treatment of adults with severe sinusitis; however, cefprozil was associated with a significantly lower incidence of diarrhea, nausea, and rash.

Ceftibuten: a new expanded-spectrum oral cephalosporin

OBJECTIVE

To review the antimicrobial activity, pharmacokinetics, clinical efficacy, and tolerability of ceftibuten, a new expanded-spectrum oral cephalosporin.

DATA SOURCES

Literature was identified by a MEDLINE search (January 1983-June 1996) of the medical literature, review of English-language literature and bibliographies of these articles, and data on file.

STUDY SELECTION

Clinical efficacy data were selected from all published and unpublished trials and abstracts that mentioned ceftibuten. Additional information concerning in vitro susceptibility, safety, chemistry, and pharmacokinetic profile of ceftibuten also was reviewed.

DATA SYNTHESIS

Ceftibuten, an oral expanded-spectrum cephalosporin, has a broad spectrum of activity against many gram-negative and selected gram-positive organisms, including Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis, and Haemophilus influenzae. Ceftibuten is stable to hydrolysis by many common beta-lactamases. Ceftibuten is rapidly and almost completely absorbed from the gastrointestinal tract and is primarily eliminated renally as unchanged drug. The elimination half-life of ceftibuten is slightly longer than 2 hours. Efficacy has been demonstrated in a number of clinical trials in adults and children with upper and lower respiratory tract infections (e.g., acute otitis media, pharyngitis, sinusitis, bronchitis) and urinary tract infections. The adverse effect profile is equal to that of comparator agents.

CONCLUSIONS

Ceftibuten is an alternative to other antimicrobial agents with convenient once-daily dosing in the treatment of upper and lower respiratory tract infections. Similar to other oral expanded-spectrum cephalosporins, ceftibuten has antimicrobial activity against common pathogens of the respiratory tract and is stable in the presence of many beta-lactamases. The clinical choice of an oral expanded-spectrum cephalosporin will be based on patient acceptance, frequency of administration, and cost.

Antimicrobial treatment in acute maxillary sinusitis: a meta-analysis

OBJECTIVE

The aims of this study were to assess which antibiotic is most effective in the treatment of acute maxillary sinusitis in otherwise healthy adults and adolescents, and which has the fewest side effects.

DESIGN

To assess the short-term effects of antimicrobial treatments, a meta-analysis was performed using Mantel-Haenszel procedures on 16 comparative, randomized studies with a total number of 3358 patients. No placebo-controlled studies were available. Antimicrobial treatments were categorized according to type, spectrum, beta-lactamase inhibition, and bactericidal effect. Outcomes were clinical cure, clinical success, and adverse events.

RESULTS

When studies were analyzed separately, we found significant differences between cefpodoxim and cefaclor in relation to clinical cure, and between loracarbef and doxycycline in relation to clinical success. When data was pooled, sulphonamides were significantly more effective than penicillins in relation to clinical cure, and macrolids were more effective than penicillins in relation to clinical success, whereas cephalosporins caused significantly less adverse events than penicillins. When studies were stratified (standard classic meta-analysis), antibiotics with beta-lactamase inhibition offered significantly more clinical cures than antibiotics without beta-lactamase inhibition. However, this significant effect was only due to one study from Southern Europe, published before 1991.

CONCLUSION

Differences in outcome between antimicrobial treatments of acute sinusitis in otherwise healthy adults and adolescents appear to be small. Therefore, the cheapest antimicrobial treatment can be selected.

Comparison of cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and ceftibuten

OBJECTIVE

To discuss the pharmacokinetics, spectrum of activity, clinical trials, and adverse effects of cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and ceftibuten, an investigational cephalosporin.

DATA SOURCES

Literature was identified by a MEDLINE search from 1986 to January 1995.

STUDY SELECTION

Randomized, controlled studies were selected for evaluation; however, uncontrolled studies were included when data were limited for indications approved by the Food and Drug Administration.

DATA EXTRACTION

Data were evaluated with respect to in vitro activity, study design, clinical and microbiologic outcomes, and adverse drug reactions.

DATA SYNTHESIS

Cefprozil, cefpodoxime proxetil, loracarbef, cefixime, and cefributen are active in vitro against organisms frequently involved in community-acquired infections such as Streptococcus pneumoniae, Escherichia coli, beta-lactamase-positive or -negative Haemophilus influenzae, and Moraxella catarrhalis. Except for cefixime and ceflibuten, they all are active against methicillin-susceptible Staphylococcus aureus. Even though there were problems in study design (discussed within the text), clinical data demonstrate that these new oral beta-lactam compounds are as efficacious as conventional therapies for a variety of community-acquired infections.

CONCLUSIONS

Cefprozil, cefpodoxime, cefixime, loracarbef, and ceftibuten demonstrate in vitro activity against the major organisms that cause community-acquired infections. Clinical trials confirm that these agents are as effective as traditional therapies for the management of acute otitis media, pharyngitis/tonsillitis, sinusitis, bronchitis, pneumonia, urinary tract infections, and skin and skin-structure infections. In addition, cefixime and cefpodoxime are effective therapies for uncomplicated gonococcal infections. Selection of a specific agent will be influenced by susceptibility data and safety, as well as issues of compliance and cost.

Multiple-dose pharmacokinetics of ceftibuten in healthy volunteers

The pharmacokinetics of ceftibuten, a new cephalosporin antibiotic, and its conversion product, ceftibutentrans, were studied in healthy male volunteers following daily oral administration of a 400-mg capsule for 7 days. Mean concentrations of ceftibuten in plasma obtained on day 5 were similar to those obtained on day 7. Analysis of variance indicated that the concentrations in plasma on days 5 and 7 were at steady state. The mean accumulation factor was 1.14 for day 5 and 1.13 for day 7. The half-life (2.4 h) was independent of the duration of drug administration, and the mean maximum concentration of drug in plasma was 18 to 19 micrograms/ml. Urinary excretion was the major elimination route for ceftibuten, by which 57 to 59% of the drug was excreted unchanged over a 24-h period. The amounts of ceftibuten-trans in plasma and urine were low.