Ceftibuten vs. penicillin V in group A beta-hemolytic streptococcal pharyngitis. Members of the Ceftibuten Pharyngitis International Study Group

Treatment Challenges of Group A Beta-hemolytic Streptococcal Pharyngo-Tonsillitis

Introduction  Despite its in vitro efficacy, penicillin often fails to eradicate Group A β-hemolytic streptococci (GABHS) from patients with acute and relapsing pharyngo-tonsillitis (PT). Objective  This review of the literature details the causes of penicillin failure to eradicate GABHS PT and the therapeutic modalities to reduce and overcome antimicrobial failure. Data Synthesis  The causes of penicillin failure in eradicating GABHS PT include the presence of β lactamase producing bacteria (BLPB) that "protect" GABHS from any penicillin; the absence of bacteria that interfere with the growth of GABHS; co-aggregation between GABHS and Moraxella catarrhalis; and the poor penetration of penicillin into the tonsillar tissues and the tonsillo-pharyngeal cells, which allows intracellular GABHS and Staphylococcus aureus to survive. The inadequate intracellular penetration of penicillin can allow intracellular GABHS and S. aureus to persist. In the treatment of acute tonsillitis, the use of cephalosporin can overcome these interactions by eradicating aerobic BLPB (including M. catarrhalis), while preserving the potentially interfering organisms and eliminating GABHS. Conclusion  In treatment of recurrent and chronic PT, the administration of clindamycin, or amoxicillin-clavulanic acid, can eradicate both aerobic and anaerobic BLPB, as well as GABHS. The superior intracellular penetration of cephalosporin and clindamycin also enhances their efficacy against intracellular GABHS and S. aureus.

Reported rates of diarrhea following oral penicillin therapy in pediatric clinical trials

OBJECTIVES

Antibiotic-associated diarrhea (AAD) is a well-recognized adverse reaction to oral penicillins. This review analyzed the literature to determine the incidence of AAD following amoxicillin, amoxicillin/clavulanate, and penicillin V oral therapy in pediatric clinical trials.

METHODS

An advanced search was conducted in MEDLINE and Embase databases for articles in any language reporting the incidence of AAD following oral penicillin therapy for any indicated infection in children (0-17 years). The search was limited to clinical trials. Articles were excluded if treatment was related to chronic conditions, involved concomitant antimicrobials, or if the dose or number of patients was not specified.

RESULTS

Four hundred thirty-five articles relating to clinical trials were identified (307 from Embase; 128 from MEDLINE). Thirty-five articles reporting on 42 studies were included for analysis. The indications included acute otitis media, sinusitis, pharyngitis, and pneumonia. Thirty-three trials reported on amoxicillin/clavulanate, 6 on amoxicillin, and 3 on penicillin V. In total, the 42 trials included 7729 children who were treated with an oral penicillin. On average, 17.2% had AAD. Data were pooled for each penicillin. The AAD incidence was 19.8% for amoxicillin/clavulanate, 8.1% for amoxicillin, and 1.2% for penicillin V. The amoxicillin/clavulanate data were analyzed according to formulation: pooled-average. The incidence of ADD was 24.6% for the 4:1 formulation, 12.8% for the 7:1 formulation, 19.0% for the 8:1 formulation, and 20.2% for the 14:1 formulation.

CONCLUSIONS

These results demonstrate substantially increased incidence of AAD following use of amoxicillin/clavulanate, compared to use of amoxicillin and penicillin V, as well as varying AAD rates with diffierent amoxicillin/clavulanate formulations. These findings warrant consideration when prescribing. The underlying mechanisms of AAD in children remain unclear.

Frequency of symptomatic relapses of group A beta-hemolytic streptococcal tonsillopharyngitis in children from 4 pediatric practices following penicillin, amoxicillin, and cephalosporin antibiotic treatment

The objective was to determine the frequency of early symptomatic relapses following antibiotic treatment for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis in children from Rochester, New York; Houston, Texas; Spokane, Washington; and Los Angeles, California (2004--2006). The study included 4278 patients. The proportion with a bacteriologic relapse of GABHS tonsillopharyngitis within 1 to 5 days of completing a 10-day treatment course was 8% (penicillin and bicillin), 6% (amoxicillin), 2% (first-generation cephalosporin), and 1% (second-generation and third-generation cephalosporin; P = .0001); symptomatic relapses occurred within 6 to 20 days after completion of therapy in 16%, 14%, 9%, and 7% of cases (P = .0001). Cases from New York and Washington had higher penicillin or amoxicillin failure rates than cases from Texas and California. The frequency of symptomatic relapses of GABHS tonsillopharyngitis, therefore, differs according to the antibiotic treatment selected; the trend for such relapses being penicillin or amoxicillin > cephalosporins although geographic differences may occur.

Comparison of European and U.S. results for cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis

The outcome of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis may differ between Europe and the USA. In the present study, Medline, Embase, reference lists, and abstract searches were used to identify randomized, controlled trials of cephalosporin versus penicillin treatment of group A streptococcal (GAS) tonsillopharyngitis. The outcomes of interest were bacteriologic and clinical cure rates from investigations conducted in Europe versus those conducted in the USA. Forty-seven trials involving 11,426 patients were included in the meta-analyses. For the comparison of 10 days of treatment with cephalosporins versus 10 days of treatment with penicillin, there were ten European and 25 U.S. trials, all involving pediatric subjects. The overall odds ratio (OR) favored cephalosporins more strongly in bacteriologic cure rate in Europe (OR=4.27, p<0.00001) than in the USA (OR=2.70, p<0.00001). Studies of 4-5 days of cephalosporin treatment versus 10 days of penicillin treatment were also analyzed. For nine European trials, the OR significantly favored cephalosporins (OR=1.30, p=0.03) in bacteriologic cure rates, but not as strongly as in the USA, (OR=2.41, p<0.00001). When results for 4-5 days of cephalosporin treatment were divided into pediatric versus adult populations, the differences in bacteriologic eradication rates obtained with cephalosporins were more pronounced in children. The likelihood of bacteriologic and clinical failure of GAS tonsillopharyngitis treatment in both European and U.S. patients is significantly less if a 10-day course of oral cephalosporin is prescribed, and is at least similar, if not significantly less, with a 4- to 5-day course of oral cephalosporin compared with a 10-day course of oral penicillin.

Meta-analysis of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis in children

OBJECTIVE

To conduct a meta-analysis of randomized, controlled trials of cephalosporin versus penicillin treatment of group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis in children.

METHODOLOGY

Medline, Embase, reference lists, and abstract searches were conducted to identify randomized, controlled trials of cephalosporin versus penicillin treatment of GABHS tonsillopharyngitis in children. Trials were included if they met the following criteria: patients <18 years old, bacteriologic confirmation of GABHS tonsillopharyngitis, random assignment to antibiotic therapy of an orally administered cephalosporin or penicillin for 10 days of treatment, and assessment of bacteriologic outcome using a throat culture after therapy. Primary outcomes of interest were bacteriologic and clinical cure rates. Sensitivity analyses were performed to assess the impact of careful clinical illness descriptions, compliance monitoring, GABHS serotyping, exclusion of GABHS carriers, and timing of the test-of-cure visit.

RESULTS

Thirty-five trials involving 7125 patients were included in the meta-analysis. The overall summary odds ratio (OR) for the bacteriologic cure rate significantly favored cephalosporins compared with penicillin (OR: 3.02; 95% confidence interval [CI]: 2.49-3.67, with the individual cephalosporins [cephalexin, cefadroxil, cefuroxime, cefpodoxime, cefprozil, cefixime, ceftibuten, and cefdinir] showing superior bacteriologic cure rates). The overall summary OR for clinical cure rate was 2.33 (95% CI: 1.84-2.97), significantly favoring the same individual cephalosporins. There was a trend for diminishing bacterial cure with penicillin over time, comparing the trials published in the 1970s, 1980s, and 1990s. Sensitivity analyses for bacterial cure significantly favored cephalosporin treatment over penicillin treatment when trials were grouped as double-blind (OR: 2.31; 95% CI: 1.39-3.85), high-quality (OR: 2.50; 95% CI: 1.85-3.36) trials with well-defined clinical status (OR: 2.12; 95% CI: 1.54-2.90), with detailed compliance monitoring (OR: 2.85; 95% CI: 2.33-3.47), with GABHS serotyping (OR: 3.10; 95% CI: 2.42-3.98), with carriers eliminated (OR: 2.51; 95% CI: 1.55-4.08), and with test of cure 3 to 14 days posttreatment (OR: 3.53; 95% CI: 2.75-4.54). Analysis of comparative bacteriologic cure rates for the 3 generations of cephalosporins did not show a difference.

CONCLUSIONS

This meta-analysis indicates that the likelihood of bacteriologic and clinical failure of GABHS tonsillopharyngitis is significantly less if an oral cephalosporin is prescribed, compared with oral penicillin.

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Efficacy of penicillin vs. amoxicillin in children with group A beta hemolytic streptococcal tonsillopharyngitis

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral penicillin versus amoxicillin as first-line therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. The prospective observational study was conducted over 18 months (January 2000-June 2001). Children enrolled had acute onset of symptoms and signs and a laboratory-documented GABHS tonsillopharyngitis illness. Follow-up examination and laboratory testing occurred 10 +/- 4 days following completion of treatment. In total, 389 patients were enrolled (intent-to-treat group): 195 received penicillin V and 194 received amoxicillin. Fifty-six of the penicillin-treated and 57 amoxicillin-treated patients refused to take the drug, or were noncompliant, or did not return for the follow-up visit, leaving 276 patients in the per-protocol group: 139 penicillin-treated and 137 amoxicillin-treated. Bacteriologic cure for amoxicillin-treated children occurred in 76% versus 64% in the penicillin-treated children (p = 0.04). The clinical cure rate for amoxicillin-treated children was 84% compared to 73% in the penicillin-treated children (p = 0.03). Since treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. The odds ratio (OR) estimate for cure for patients in the amoxicillin versus penicillin V treatment group remained significant (OR = 1.84, 95% confidence interval 1.02-3.29); the same was true for dinical cure (OR = 1.99, 95% CI = 1.02-3.87). Amoxicillin may be superior to penicillin for bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Etiology and Management of Acute and Recurrent Group A Streptococcal Tonsillitis

Tonsillitis is one of the most prevalent infections in children and adolescents. The etiologic agents might be viral or bacterial. About 30% of cases are reported to be of bacterial origin, mainly due to group A Streptococcus (GAS). Although in most instances GAS tonsillitis is a self-limited disease, antibiotic treatment is recommended, mainly to prevent the suppurative and nonsuppurative poststreptococcal sequelae of acute rheumatic fever and to prevent glomerulonephritis. In this paper we review the current knowledge of the etiology of acute and recurrent GAS tonsillitis, with special emphasis on a recent hypothesis regarding the etiology of bacterial eradication failure. While penicillin V remains the drug of choice for acute tonsillitis, other antibiotics are being approved and recommended for particular indications in both Europe and the United States.

New approaches to the treatment of group A streptococcal pharyngitis

An orally administered antimicrobial regimen for the treatment of pharyngitis caused by group A beta-hemolytic streptococci that could be given once daily and for less than 10 days would be convenient and might improve compliance, decrease cost, and result in fewer side effects compared with a regimen given multiple times daily for 10 days. Previous attempts to administer oral penicillin once daily or for less than 10 days were not successful. Several cephalosporins and azithromycin have been reported to be effective when administered once daily or for less than 10 days. However, large, comprehensive studies have not been performed. In addition, the spectra of these cephalosporins and azithromycin are much broader than that of penicillin, and, even when they are administered for short courses, they are more expensive. Therefore, these novel regimens cannot be endorsed and should not supplant penicillin as the agent of choice. In contrast, once-daily amoxicillin therapy appears to be effective, is inexpensive, and has a narrower spectrum of antimicrobial activity; if these findings are confirmed by additional investigations, it could become an alternative regimen for the treatment of pharyngitis caused by group A beta-hemolytic streptococci.

The new antibiotics

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

Short course therapy with cefitbuten versus azithromycin in pediatric streptococcal pharyngitis

OBJECTIVE

To compare the safety and efficacy of a short course (5 days) of ceftibuten vs. azithromycin for 3 days for treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis in children.

METHODS

A multicenter, open label, prospective, randomized trial in which patients > or =3 to < or =16 years of age with proven GABHS pharyngitis were randomized to receive either once daily ceftibuten for 5 days or azithromycin for 3 days. Patients were evaluated for clinical outcomes and/or for adverse events at days 6 to 8, 13 to 15 and 33 to 35 posttherapy. Microbiologic assessments (pharyngeal cultures) were conducted at baseline and at each follow-up visit.

RESULTS

A total of 132 patients in the ceftibuten arm and 116 in the azithromycin arm were enrolled in the safety analysis, whereas 126 and 101, respectively, were enrolled for ceftibuten and azithromycin efficacy evaluation. Clinical success (cure or marked amelioration) at days 6 to 8 was recorded in 98 and 94% in the 2 groups, respectively. In the bacteriologic efficacy analysis at 6 to 8 days, the GABHS strain was eradicated in 76% of the patients treated with ceftibuten and in 76% of those receiving azithromycin. At 33 to 35 days, 84% of the patients in the ceftibuten arm and 71% in the azithromycin arm were GABHS-negative, and bacteriologic relapse was observed in 4 and 7% of the ceftibuten and azithromycin cases, respectively. Both treatments were well-tolerated by all patients.

CONCLUSIONS

Ceftibuten and azithromycin allow simple treatment schedules (i.e. once daily administration, short duration of treatment). The somewhat higher eradication rate recorded after ceftibuten administration is consistent with the overall superior bactericidal activity of beta-lactams compared with macrolides vs. GABHS in vitro.

Penicillin failure in streptococcal tonsillopharyngitis: causes and remedies

Penicillin administered for 10 days has been the treatment of choice for group A beta-hemolytic streptococcal tonsillopharyngitis since the 1950s. The bacteriologic failure rate of 10 days of penicillin therapy ranged from approximately 2 to 10% until the early 1970s. Beginning in the late 1970s bacteriologic and clinical failure rates with penicillin therapy began to increase steadily over time and are now reported to be approximately 30%. The primary cause of penicillin treatment failure in streptococcal tonsillopharyngitis may be lack of compliance with the 10-day therapeutic regimen. Other causes of penicillin treatment failure include reexposure to Streptococcus-infected family members or peers; copathogenicity, in which bacteria susceptible to a class of drugs are protected by other, colocalized bacterial strains that lack the same susceptibility; antibiotic-associated eradication of normal protective pharyngeal flora; and penicillin tolerance, whereby streptococcal bacteria repeatedly or continuously exposed to sublethal concentrations of antibiotic become increasingly resistant to eradication. Although 10 days of penicillin therapy is effective in the management of tonsillopharyngitis for many patients, multiple factors may, singly or together, cause treatment failure. A number of antibiotics, particularly the cephalosporins, have been demonstrated to be superior to penicillin at eradicating group A beta-hemolytic Streptococcus, and several are effective when administered for 4 to 5 days.

CONCLUSIONS

Ten days of penicillin therapy may not be the best therapeutic choice for all pediatric patients. Other antibiotics, shortened courses of the cephalosporins in particular, may be preferable in some cases.

Potential mechanisms for failure to eradicate group A streptococci from the pharynx

OBJECTIVE

To investigate the relative efficacy of orally administered cefadroxil and penicillin V in the treatment of group A streptococcal (GABHS) pharyngitis and the mechanism(s) responsible for failure of antimicrobial therapy to eradicate GABHS from the pharynx.

STUDY DESIGN

A prospective, randomized clinical trial was conducted in four pediatric offices in which 462 patients with acute pharyngitis and positive culture for GABHS were randomly assigned to receive cefadroxil (n = 232) or penicillin V (n = 230).

RESULTS

Bacteriologic treatment success rates for patients in cefadroxil and penicillin groups were 94% and 86%, respectively. However, among patients classified clinically as likely to have bona fide GABHS pharyngitis, there was no difference in bacteriologic treatment success rates in cefadroxil and penicillin groups (95% and 94%, respectively). Among patients classified clinically as likely to be streptococcal carriers, bacteriologic treatment success rates in cefadroxil and penicillin groups were 92% and 73%, respectively. The presence of beta-lactamase and/or bacteriocin-producing pharyngeal flora had no consistent effect on bacteriologic eradication rates among patients in either penicillin or cefadroxil treatment groups or among patients classified as having either GABHS pharyngitis or streptococcal carriage.

CONCLUSIONS

Neither beta-lactamase nor bacteriocin produced by normal pharyngeal flora are related to bacteriologic treatment failures in GABHS pharyngitis. Cefadroxil seems to be more effective than penicillin V in eradicating GABHS from patients classified as more likely to be streptococcal carriers. However, among patients we classified as more likely to have bona fide GABHS pharyngitis, the effectiveness of cefadroxil and penicillin V seems to be comparable.

Once-daily therapy for streptococcal pharyngitis with amoxicillin

OBJECTIVE

An orally administered antimicrobial regimen for the treatment of group A beta-hemolytic streptococcal (GABHS) pharyngitis given once rather than multiple times each day would be more convenient and might result in improved patient compliance. The purpose of this study was to evaluate the effectiveness of once-daily amoxicillin in the treatment of GABHS pharyngitis.

PATIENTS

Children presenting to a private pediatric office with GABHS pharyngitis.

DESIGN

Patients were randomly assigned to receive orally either amoxicillin (750 mg once daily) or penicillin V (250 mg three times a day) for 10 days. Compliance was monitored by urine antimicrobial activity.

OUTCOMES

Outcomes were measured by impact on the clinical course, eradication of GABHS within 18 to 24 hours, and bacteriologic treatment failure rate as determined by follow-up throat cultures 4 to 6 and 14 to 21 days after completing therapy. GABHS isolates were serotyped to distinguish bacteriologic treatment failures (same serotype as initial throat culture) from new acquisitions (different serotypes).

RESULTS

During the 16 months of this study, 152 children between 4 and 18 years of age (mean, 9.9 years) were enrolled; 79 children were randomly assigned to receive once-daily amoxicillin and 73 were assigned to receive penicillin V three times a day. The children in the two treatment groups were comparable with respect to age, duration of illness before initiation of therapy, compliance, and signs and symptoms at presentation. There was no significant difference in the clinical or bacteriologic responses of the patients in the two treatment groups at the 18- to 24-hour follow-up visit. Bacteriologic treatment failures occurred in 4 (5%) of the 79 patients in the amoxicillin group and in 8 (11%) of the 73 patients in the penicillin V group.

CONCLUSIONS

These data demonstrate that once-daily amoxicillin therapy is as effective as penicillin V therapy given three times a day for the treatment of GABHS pharyngitis, and if confirmed by additional investigations, once-daily amoxicillin therapy could become an alternative regimen for the treatment of this disease.

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.

Empiric antibiotic selection criteria for respiratory infections in pediatric practice

BACKGROUND

Respiratory infections in children may occur as a consequence of resistant bacterial pathogens. Streptococcus pneumoniae organisms resistant to penicillin, trimethoprim/sulfamethoxazole and macrolides are increasingly prevalent. Amoxicillin- and macrolide-resistant Haemophilus influenzae and Moraxella (Branhamella) catarrhalis are also more commonly seen. Traditional agents such as amoxicillin and trimethoprim/sulfamethoxazole remain acceptable choices for most children with respiratory infections because currently most patients are not infected by resistant pathogens and there is a high spontaneous cure rate associated with these infections.

OBJECTIVE

To analyze the criteria for the selection of extended spectrum antimicrobials as empiric therapy for respiratory infections.

DISCUSSION

When an extended spectrum antimicrobial is appropriate for empiric therapy, selection should be based on: (1) efficacy; (2) adverse event profile; and (3) compliance-enhancing features (dosing with meals, once or twice daily administration, good palatability in suspension, shortened course of therapy and affordability). A new agent, ceftibuten, has recently joined other extended spectrum cephalosporins and newer macrolides (clarithromycin and azithromycin) as a choice to be considered for empiric therapy for respiratory infections. These antimicrobials are differentiated from each other and traditional agents by differences in activity in vitro against penicillin-resistant pneumococci, relative beta-lactamase stability against Gram-negative bacteria and pharmacodynamic properties. When resistant organisms are isolated or suspected in community-acquired respiratory infections, cautious use of newer antibiotics may have to be considered.

Ceftibuten concentrations in human tonsillar tissue

In a study designed to determine ceftibuten concentrations in tonsillar tissue, subjects scheduled to undergo tonsillectomy were administered 400 mg of ceftibuten in a single oral dose. Between 2 and 24 h after the dose was given, tonsillar tissue samples were taken during surgery and assayed for ceftibuten. Mean concentrations in tonsillar tissue 4.4 h and 24.6 h after the 400 mg dose were 5.3 +/- 2.7 and 0.3 +/- mg/g, respectively. Concurrent mean serum concentrations were 7.42 +/- 1.66 and 0.15 +/- 0.13 mg/ml, respectively. The apparent half-life of drug in the tissue was 5.3 h. The presence of high ceftibuten concentrations in tonsillar tissue suggests that a once-daily regimen may be effective in treating tonsillitis and pharyngitis.

Pharyngitis

This article reviews the commonly encountered agents causing acute inflammation of the pharynx and tonsils, with special attention to a practical approach for identifying and dealing with the group A beta-hemolytic streptococcus. Ubiquitous viral agents such as Epstein-Barr virus, rhinovirus, and adenovirus are reviewed. Some agents such as group A beta-hemolytic streptococcus and Epstein-Barr virus are susceptible to treatment. Additionally, unusual infectious agents and noninfectious causes of pharyngitis are enumerated.

Comparative bioavailability of ceftibuten in capsule and suspension forms

The comparative bioavailability of ceftibuten, a new third-generation cephalosporin antibiotic given orally once daily, in capsule and suspension dosage forms, was assessed in healthy male subjects. In three separate studies, subjects received either a 400-mg dose as a suspension or one laboratory-batch, 400-mg capsule; one laboratory-batch, 400-mg capsule or two laboratory-batch, 200-mg capsules; or one production-batch, 400-mg capsule or two laboratory-batch, 200-mg capsules. Plasma samples were assayed for ceftibuten using high-performance liquid chromatography, and the data were assessed using pharmacokinetic and statistical methods. Confidence intervals for the maximum plasma concentration and the area under the plasma concentration-time curve extrapolated to infinity were within 80% to 125% of guidelines, demonstrating the bioequivalence of the two treatments within each of the three studies. One 400-mg capsule (laboratory or production batch) was bioequivalent to two 200-mg capsules used in a clinical efficacy trial; the 400-mg suspension was bioequivalent to a 400-mg capsule (laboratory batch). Thus we concluded that the capsule and the suspension dosage forms were bioequivalent.

Streptococcal pharyngitis: is penicillin still the drug of choice?

With the advent of cephalosporins, penicillin appears to have lost some ground for treatment of Acute Group A Beta Hemolytic Streptococcal Pharyngitis. It has been argued for some time now whether penicillin should remain the drug of choice for the management of this infection. Evidence has been presented both in favour and against using penicillin for Group A beta hemolytic streptococcal (GABHS) pharyngotonsillitis. In this commentary, we review the available data in the current literature and conclude that penicillin should still remain the drug of first consideration for GABHS pharyngitis. If penicillin treatments were less effective now, the clinical and bacteriologic failure rates should be on the rise compared to the previous years.

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.