Cefixime vs. cefaclor in the treatment of acute otitis media in infants and children

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.

Comparison of study designs for acute otitis media trials

BACKGROUND

A framework for evaluating the efficacy of antibiotics in development as well as those currently approved for acute otitis media (AOM) is needed.

OBJECTIVE

Review strengths and limitations of various antibiotic trial designs and their outcome measures.

METHODS

A review of 157 published trials involving 36,710 subjects for the treatment of AOM.

RESULTS

AOM trials have three designs: (1) clinical, clinical diagnosis and assessment of outcomes; (2) single tympanocentesis, microbiologic diagnosis (by middle ear fluid culture) and clinical assessment of outcomes; and (3) double tympanocentesis, microbiologic diagnosis and microbiologic outcome assessment. Identifiable strengths and limitations of each design are reviewed. Case definitions for entry of children in trials of AOM vary widely. The lack of stringent diagnostic criteria in a clinical design allows for inclusion of a significant proportion of children with a non-bacterial etiology (i.e., viral AOM or otitis media with effusion). Tympanocentesis increases diagnostic accuracy at study entry; however, the procedure is confounding because of its potentially therapeutic benefit and the procedure is not performed in a uniform manner. A second tympanocentesis allows a high sensitivity to detect microbiologic eradication, but it does not correlate with clinical outcomes in half of the cases. The timing of outcome assessment also varies widely among trials.

CONCLUSIONS

Improved clinical diagnosis criteria for AOM are needed to enhance specificity; emphasis on a bulging tympanic membrane has the best evidence base. Tympanocentesis within study designs has merits. At study entry it assures diagnostic accuracy but may alter outcomes and it is useful to document microbiologic outcomes but lacks specificity for clinical outcomes. For all designs, test of cure assessment 2-7 days after completion of therapy seems most appropriate.

Studies in otitis media: Children's Hospital of Pittsburgh-University of Pittsburgh progress report--2004

OBJECTIVES/HYPOTHESIS

The present Progress Report has summarized the key otitis media clinical trials and laboratory studies conducted since 1969 by investigators at the Children's Hospital of Pittsburgh-University of Pittsburgh (Pittsburgh, PA).

STUDY DESIGN

Review.

METHODS

Included in the discussion are the following: 1) studies of the epidemiology and risk factors; 2) anatomy and pathology of the eustachian tube-middle ear from human temporal bone histopathological specimens; 3) physiology and pathophysiology of the eustachian tube-middle ear in humans and animal models; 4) pathogenesis; 5) otitis media in special populations (e.g., patients with cleft palate, Native Americans, patients with Down syndrome); 6) microbiology; 7) diagnosis; 8) outcomes of randomized clinical trials that evaluated efficacy of nonsurgical and surgical methods of treatment and prevention; 9) studies of certain complications and sequelae (e.g., effect of middle-ear effusion on hearing, early child development, and the vestibular system; chronic suppurative otitis media). Also included are relevant summary tables and 256 references.

Otitis media

Bacterial pathogens are isolated from middle ear fluid in up to 90% of children with acute otitis media (OM). Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis predominate. Acute OM can be classified as uncomplicated, persistent, recurrent or chronic. Patient age, symptom severity, prior treatment history and exposure through day-care attendance in children influences pathogen distribution, antimicrobial susceptibility and anticipated clinical and microbiological responses to empirical and pathogen-directed therapies. The natural history of acute OM without intervention is favourable. However, meta-analysis of clinical trials shows an improvement in symptom and middle ear effusion resolution with antimicrobials. Aminopenicillins, cephalosporins and macrolides are often selected as therapy for acute OM. The various agents have differing activity against acute OM pathogens, particularly organisms with resistance mechanisms and they differ in dosing schedule, side effects and compliance enhancing factors. Consideration should be given to pharmacokinetic and pharmacodynamic principles in antibiotic selection. Selection criteria include antibiotic activity against drug-resistant S. pneumoniae and efficacy against beta-lactamase-producing Gram-negative organisms. The necessary duration of treatment for acute OM varies according to multiple factors, including local preferences, but there is growing, compelling data to support short-course therapy. Tympanocentesis has been endorsed in various guidelines as a diagnostic and therapeutic procedure. Best-practice for management of acute OM continues to advocate antibiotic therapy with careful, accurate diagnosis and consideration of the major pathogens and their mechanisms of resistance.

Comparison of cefaclor and cefuroxime axetil in the treatment of acute otitis media with effusion in children who failed amoxicillin therapy

This trial compared the efficacy and safety of a 10-day treatment course of cefaclor and cefuroxime axetil in the treatment of acute otitis media with effusion in children who failed therapy with amoxicillin. This was an investigator-blind, randomized, parallel treatment group study. To be included, patients must have received treatment with a standard clinical regimen of amoxicillin for at least 48 hours and not more than 10 days, with the last dose within 72 hours of randomization. Patients who met the entry criteria were randomly assigned to one of two antibiotic treatment groups. Cefaclor and cefuroxime axetil suspensions were administered twice daily for a total daily dose of 40 mg/kg and 30 mg/kg, respectively. Physical examination, pneumatic otoscopy and tympanogram were performed to evaluate efficacy to therapy. Therapeutic equivalence was established by ruling out a difference (cefaclor minus cefuroxime axetil) of 15% in percentages of clinical success (cure plus improvement). Safety evaluation was performed by assessment of clinical adverse events. In the intent-to-treat analysis post-therapy (1-6 days after completion of therapy), 96 of 104 (92.3%) cefaclor-treated patients had clinical success compared to 90 of 101 (89.1%) cefuroxime axetil patients. The 95% confidence limits on the difference between proportions of favorable outcomes (cefaclor minus cefuroxime axetil) was from -4.8% to +11.2%. At termination of the study (day 10-16 after completion of therapy), 86 of 104 (82.7%) cefaclor patients and 84 of 101 (83.2%) cefuroxime axetil patients had favorable clinical outcomes (95% confidence interval: -10.8% to +9.9%). Thirty-two (30.8%) of the 104 patients in the cefaclor treatment group reported at least one adverse event, with rhinitis reported in 9 (8.7%) patients and cough increased in 7 (6.7%) patients. Thirty-six (35.6%) of the 101 patients in the cefuroxime axetil treatment group reported at least one event, with diarrhea reported in 11 (10.9%) of patients and rhinitis in 10 (9.9%) patients. Cefaclor and cefuroxime axetil were equally effective in the treatment of patients with acute otitis media with effusion who had failed therapy with amoxicillin. Significantly fewer patients treated with cefaclor reported diarrhea, which is the most frequently reported adverse event in children treated with antibiotics for this disease.

A multicenter, open label trial of azithromycin for the treatment of children with acute otitis media

OBJECTIVE

In this multicenter, open label trial the investigators evaluated the efficacy and safety of azithromycin suspension administered once daily for 5 days for the treatment of clinically and bacteriologically established acute otitis media.

METHODS

Two hundred eligible children with acute otitis media from 10 US centers were treated with 10 mg/kg of azithromycin oral suspension on Day 1, followed by 5 mg/kg once daily for the next 4 days. Tympanocentesis and subsequent culture of middle ear effusion were performed at baseline. Clinical efficacy was evaluated on Days 6, 11 and 30.

RESULTS

Analysis of clinical efficacy in evaluable patients 11 days after the initiation of therapy showed that the rate of satisfactory responses (cured or improved) ranged from 79.6 to 82.4% in patients infected with Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis. Satisfactory clinical response at Day 30 was reported in 70% of evaluable patients, and eradication of S. pneumoniae, H. influenzae and M. catarrhalis was presumed in 64 to 73%. Relapses occurred in 14% of the evaluable patients. Among the treated patients 8.5% reported mild or moderate side effects.

CONCLUSION

Azithromycin is an effective, safe and well-tolerated treatment for children with acute otitis media.

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.

Clinical efficacy of antimicrobial drugs for acute otitis media: metaanalysis of 5400 children from thirty-three randomized trials

OBJECTIVE

To reconcile conflicting published reports concerning the absolute and comparative clinical efficacy of antimicrobial drugs for acute otitis media in children.

STUDY SELECTION

Articles were identified by MEDLINE search, Current Contents, and references from review articles, textbook chapters, and retrieved reports. Randomized, controlled trials of therapeutic antimicrobial drugs used in the initial empiric therapy for simple acute otitis media were selected by independent, blinded observers, and scored on 11 measures of study validity. Thirty English and three foreign-language articles met all inclusion criteria.

DATA EXTRACTION

Data were abstracted for an end point of complete clinical resolution (primary control), exclusive of middle ear effusion, within 7 to 14 days after therapy started.

DATA SYNTHESIS

The spontaneous rate of primary control--without antibiotics or tympanocentesis--was 81% (95% confidence interval, 69% to 94%). Compared with placebo or no drug, antimicrobial therapy increased primary control by 13.7% (95% confidence interval, 8.2% to 19.2%). No significant differences were found in the comparative efficacy of various antimicrobial agents. Extending antimicrobial coverage to include beta-lactamase-producing organisms did not significantly increase the rates of primary control or resolution of middle ear effusion. Pretreatment tympanocentesis was positively associated with individual group primary control rates, negatively associated with the ability to detect differences in clinical efficacy and unassociated with resolution of MEE.

CONCLUSIONS

Antimicrobial drugs have a modest but significant impact on the primary control of acute otitis media. Treatment with beta-lactamase-stable agents does not increase resolution of acute symptoms or middle ear effusion; initial therapy should be guided by considerations of safety, tolerability, and affordability, and not by the theoretical advantage of an extended antibacterial spectrum.

A review of clinical trials regarding treatment of acute otitis media

A survey was made of the English language literature on clinical trials of therapy in acute otitis media. The articles were analysed systematically for 24 parameters related to study design. We retrieved 50 studies published between 1965 and 1989. Surprisingly, the combination of a double-blind method, clearly defined inclusion criteria, and criteria for outcome was found in only 13 studies. Most of these 13 compared different antibiotic regimens and only 4 were placebo-controlled. A recommendation based on the conclusions reached can, even in these 13 studies, hardly be obtained due to failure to show an overall difference in favour of a specific treatment regimen. Our study shows that many trials are methodologically flawed which makes it difficult to accept their results. In view of current controversy on management of acute otitis media, well conducted placebo-controlled clinical trials are still needed.

The oral cephalosporins--a review

There are currently six cephalosporins available in the United States for oral use. These agents possess a wide spectrum of activity, are relatively safe to use, and are effective for certain infections involving the respiratory tract, skin, and urinary tract. Nonetheless, in general, they offer no advantage over other classes of antimicrobial drugs and are far more expensive. As a result, the oral cephalosporins are not agents of first choice for the treatment of infection but should be reserved for use as alternative therapy.

Cefixime compared with amoxicillin for treatment of acute otitis media

Cefixime was compared with amoxicillin for treatment of acute otitis media in a randomized trial. Results of tympanocentesis on day 3 to 5 of therapy were used as the major outcome. Total daily doses were 8 mg/kg of cefixime and 40 mg/kg of amoxicillin. One hundred twenty-six patients were randomly assigned to receive treatment; 64 cultures grew pathogens. Pathogens were eradicated from the middle ear after 3 to 5 days of therapy in 27 (79.4%) of 34 children given amoxicillin and 26 (86.7%) of 30 children given cefixime (p = 0.47). When Streptococcus pneumoniae cases were analyzed, bacteriologic cure occurred in 14 (93.3%) of 15 children given amoxicillin and 12 (75%) of 16 given cefixime (p = 0.333). When cases of Haemophilus influenzae infection were analyzed, significantly more cures occurred with cefixime (10/10, 100%) than amoxicillin (8/13, 62%) (p = 0.046). Pathogens associated with failure of amoxicillin therapy were H. influenzae (five cases, two beta-lactamase-positive), S. pneumoniae (one case), and Moraxella catarrhalis (one case, beta-lactamase-positive). The four failures with cefixime therapy were all in patients infected with S. pneumoniae. Rates of rash, diarrhea, and vomiting were the same in both groups and did not necessitate stopping therapy. We conclude the following: (1) Cefixime and amoxicillin were equivalent in overall clinical and bacteriologic efficacy for otitis media. (2) Cefixime was more efficacious than amoxicillin in treating H. influenzae otitis media and should be preferred when H. influenzae is the suspected etiologic agent. (3) Side effects of both drugs were mild and equivalent.

Double-blind comparison of cefixime and cefaclor in the treatment of acute otitis media in children

In a double-blind study cefixime, an oral cephalosporin of the third generation, was compared to cefaclor in the treatment of acute otitis media in 397 children aged 6 months to 12 years. Clinical evaluation was carried out at the beginning, at day 10-12 and day 28-35 after the start of the treatment. Specimens for bacterial culture and sensitivity testings were taken from the nasopharynx at the initial visit. Patients were randomized either to cefixime in a dose of 8 mg/kg/day or cefaclor in a dose 40 mg/kg/day in the proportion of 2 cefixime patients to 1 cefaclor patient. Two daily doses were administered for 7 days. At day 10-12, 93.5% in the cefixime group and 90.5% in the cefaclor group (p = 0.08) were clinically cured or improved. At day 28-35 the rate of cured or improved patients had decreased, mostly due to reinfections, to 90.1% in the cefixime group and to 86.6% in the cefaclor group (p = 0.12), respectively. 375 patients (69.9%) had positive bacterial culture in the nasopharynx of at least one strain of Haemophilus influenzae, Streptococcus pneumoniae, Branhamella (Moraxella) catarrhalis or combinations of these 3.73.6% of the B. catarrhalis strains were beta-lactamase producing and 11.4% of the H. influenzae strains, respectively. All isolated bacteria were sensitive to cefixime. Adverse events were reported in 17.9% in the cefixime and 10.6% in the cefaclor group. Most reactions were of moderate or mild nature and mostly affected skin or the gastrointestinal region. No serious adverse experiences occurred. In view of the good clinical results obtained cefixime seems to be at least as effective as cefaclor in the treatment of acute otitis media in children.

The new antimicrobial agents. When they're the best choice and when they're not

The number of antibiotics available to the clinician for treatment of infectious diseases continues to increase. However, choosing an agent just because it is new is not always cost-effective and may encourage the development of bacterial resistance. The site of infection, pharmacokinetic data, minimum inhibitory concentration, and cost must all be considered in selecting the optimal antimicrobial agent for a particular clinical situation.

[Therapy of pediatric infections with cefixime]

In a pilot study with a limited number of patients the efficacy and tolerance of cefixime, a new oral cephalosporin antibiotic, were investigated in 15 children with the clinical diagnosis of bacterial respiratory tract infection, otitis media or urinary tract infection. The dosage was 2 x 4 mg/kg body weight daily for a period of seven to 11 days. Clinical efficacy was good in 13 cases, and subjective tolerance was good in all cases. The results support the assumption that cefixime is suited for the treatment of children with bacterial infections of the airways and urinary tract with sensitive pathogens.

Cefixime

Cefixime is a new orally active third-generation cephalosporin with a broad spectrum of activity against a variety of both gram-positive and -negative bacteria including many beta-lactamase-producing strains of streptococci, Haemophilus influenzae, Neisseria gonorrhoeae, and the majority of the Enterobacteriaceae. Activity of cefixime against Staphylococcus aureus, enterococci, Listeria monocytogenes, and Pseudomonas spp. is poor. The relatively long elimination half-life of cefixime (approximately 3.0 h) has made possible once- to twice-daily administration with the potential added benefit of improved patient compliance. Clinical trials indicate that cefixime is at least as effective as standard agents in the treatment of genitourinary and upper respiratory tract infections. The incidence of resistant organisms reported during clinical trials with cefixime was low. Adverse reactions observed during clinical trials were relatively uncommon and generally mild and transient in nature. The most significant adverse reactions reported were diarrhea and stool changes occurring in up to 20 percent of patients.

Oral cephalosporins in perspective

Oral cephalosporins, after 25 years of use, continue to present the clinician with a therapeutic challenge. The older agents have been extensively prescribed for ambulatory adult and pediatric patients with a wide variety of infections caused by gram-positive and some gram-negative organisms. The newer agents, cefaclor, cefuroxime axetil, and cefixime, have increased in vitro activity against beta-lactamase-secreting strains of Haemophilus influenzae and Branhamella catarrhalis which has made them more popular for the treatment of otitis media and respiratory tract infections in children. The new agents are also more active against most gram-negative organisms. However, clinical trials have failed to show a clear-cut superiority over older, proven therapy when used to treat infections of the respiratory tract, middle ear, skin and soft tissue, urinary tract, and bone and joints when caused by sensitive organisms. Published reports of clinical trials continue to support the recommendation that oral cephalosporins, especially the newer and more expensive agents, be reserved for second- or third-line therapy when amoxicillin, penicillin V, or trimethoprim/sulfamethoxazole have either failed or produced patient intolerance. Erythromycin/sulfisoxazole and amoxicillin/clavulanate potassium are equally efficacious and also less expensive than cefaclor, cefuroxime axetil, and cefixime and could be considered second-line therapy prior to the use of the newer cephalosporins for infections in the ambulatory patient.

Modern management of otitis media

In summary, infants and children who have acute otitis media should receive antimicrobial therapy. Amoxicillin is the standard of therapy for infants and children with acute otitis media, because it is safe and effective for most of the causative bacterial pathogens. Amoxicillin has also been shown to be effective for treatment of selected children with otitis media with effusion ("secretory" otitis media) and is the recommended prophylactic antimicrobial agent for prevention of frequently recurrent acute otitis media. During the past decade, however, an increasing rate of bacteria that are resistant to amoxicillin has occurred, primarily beta-lactamase-producing H. influenzae and B. catarrhalis. Because of the emergence of these bacteria, other antimicrobial agents, both old and new, have been advocated for treatment and prevention of otitis media; amoxicillin-clavulanate, cefuroxime axetil, and cefixime are the newer agents. These agents are indicated for selected infants and children; however, for most patients, amoxicillin remains a safe and relatively inexpensive effective drug. The common surgical procedures, such as myringotomy with tympanostomy tube insertion, and adenoidectomy with myringotomy with or without tympanostomy tube insertion, have now been shown to be effective for patients who have recurrent acute otitis media and chronic otitis media with effusion. The decision for or against these procedures should not only include consultation with an otolaryngologist but should also involve the parents and the child, if old enough. The risks, costs, and benefits of nonsurgical and surgical management should be discussed with all parties concerned.