Antibiotic Treatment Of Acute Otitis Media Research Articles

From Evidence to Clinical Guidelines in Antibiotic Treatment in Acute Otitis Media in Children.

Acute otitis media (AOM) in children represents a public health concern, being one of the leading causes of health care visits and antibiotic prescriptions worldwide. The overall aim of this paper is to unravel the major current insights into the antibiotic treatment of AOM in children. Our approach is three-fold: 1. a preclinical evaluation of antibiotics in animal models of AOM stressing on the advantages of different species when testing for different schemes of antibiotics; 2. an overview on the new antimicrobial agents whose efficacy has been demonstrated in refractory cases of AOM in children; and 3. an analysis of the different guidelines stressing on the differences and similarities between the various schemes of antibiotic treatment. The preferred therapeutic agents remain amoxicillin and the amoxicillin-clavulanate combination for AOM caused by Streptococcus pneumoniae, whereas oral cephalosporin is preferred in AOM due to Moraxella catarrhalis and Haemophilus influenzae. As for the second and third line antimicrobial treatments, there is a wide variety of suggested antibiotic classes with variations in duration and posology. The decision to prescribe antimicrobial treatment as a first-line choice is based on the severity of the symptoms in 16 of the guidelines included in this review.

A Case of Epidural Abscess Complicated from Acute Mastoiditis Caused byStreptococcus pneumoniae

Acute otitis media (AOM) is one of the most common childhood infectious diseases. Despite antibiotic treatment for AOM, AOM and its complication still continue to develop. Acute mastoiditis is a serious complication of AOM and epidural abscess constitutes the commonest of all intracranial complication of AOM. Neurological complication of acute mastoiditis are rare but can be life threatening. Their presentation may be masked by the use of antibiotics. We report the rare case of acute otitis media progressing to acute mastoiditis, epidural abscess formation and lateral sinus thrombophlebitis caused by Streptococcus pneumoniae in a child. She was admitted with acute otitis media with fever. Despite proper antibiotics, acutemastodititis and epidural abscess were developed, and after surgical drainage and antibiotics therapy she was recovered without sequalae.KeyWords:Epidural abscess, Mastoiditis, Otitis media, Streptococcus pneumoniae

Impact of Acute Otitis Media Pathogen Shifts on the Clinical Efficacy of Several Antibiotics: A Therapeutic Outcomes Model

The aim of this study was to predict the clinical efficacy of different antimicrobials in the treatment of patients with acute otitis media (AOM), before and after the change in the proportion of middle ear pathogens observed after the introduction of the new conjugated heptavalent penumococcal vaccine (PCV-7). The therapeutic Outcomes model was used to predict the likelihood of clinical success. According to this mathematical model the obtained rank order of predicted clinical efficacy was similar in the pre-PVC7 period and the post-PVC period. The results suggest that ceftriaxone and amoxicillin/clavulanate are the antibiotics with the highest predicted clinical efficacy, whereas cefaclor, azithromycin, erythromycin and clarithromycin are those with the lowest predicted clinical efficacy. The differences between antibiotics with good and those with low antibacterial activity were greater when only cases of bacterial AOM were considered. Antibiotics for which the highest clinical efficacy was predicted should maximize the likelihood of cure in outpatient antibiotic treatment of AOM.

A Canadian perspective on the American Academy of Pediatrics guidelines for acute otitis media

In 2004, the American Academy of Pediatrics (AAP) and the American Academy of Family Physicians (AAFP) published guidelines on the management of acute otitis media (AOM) (1). These are summarized in Table 1. The guidelines contain new recommendations for both empirical and second-line antibiotic treatments; however, some of the drugs recommended are not available in Canada. What are these recommendations, and what are the options for the prescribing Canadian physician? TABLE 1 The American Academy of Pediatrics otitis media guidelines The AAP/AAFP clinical practice guideline is a comprehensive document that covers diagnosis and management, including weighing the option of observation and symptomatic treatment, pain control, prevention measures, as well as appropriate choices for antibacterial medications. We will address the recommended antibiotics and explain why these drugs are recommended, as well as provide options for drugs that are not available in Canada. The first major new recommendation in the AAP/AAFP guidelines is an increase in the empirical treatment dose of amoxicillin. Specifically, the guidelines recommend that for most children, if an antibacterial agent is to be used, then the first-line agent to be prescribed should be amoxicillin at 80 mg/kg/day to 90 mg/kg/day. This was based on a Centers for Disease Control and Prevention (CDC) recommendation that the empirical treatment dose of amoxicillin should be increased from 40 mg/kg/day to 45 mg/kg/day, to 80 mg/kg/day to 90 mg/kg/day, owing to the rising prevalence of drug-resistant Streptococcus pneumoniae (DRSP) (2). In general, one cannot just increase the dose of a drug to overcome resistance; however, the mechanism of penicillin resistance is such that increasing the dose of amoxicillin results in serum levels that can overcome the resistance. This is based on in vitro data, not clinical trials. Penicillin susceptibility is geographically dependent, both in the United States and Canada. Thus, the CDC guidelines acknowledge that patients at very low risk for DRSP may still be treated with a regular dose of amoxicillin. This refers to patients older than two years of age, those without antibiotic exposure in the past three months and those with no daycare attendance. Moreover, since the publication of these guidelines, new data have emerged from the United States showing a change in the relative frequency of the different isolates causing AOM as a result of conjugated pneumococcal vaccine use. A significant drop (greater than 10%) in the rates of DRSP in certain communities was reported, especially in areas in which the vaccine has had universal recommendations (3); an overall decrease in the frequency of S pneumoniae isolates relative to Haemophilus influenzae (4) causing AOM was also reported. The Canadian Paediatric Society is currently revising the Canadian guidelines for first-line antibiotic treatment of AOM. In the interim, it would seem prudent to weigh all the risk factors (eg, age, daycare attendance, previous antibiotic exposure and geographical rate of drug resistance), as well as vaccination status (5) in the decision to choose high- versus standard-dose amoxicillin. It is important to remember that high-dose amoxicillin could cause diarrhea as an adverse effect. In patients with severe illness (moderate to severe ear pain and fever of 39°C or higher) and in those who fail to respond to initial management within 48 h to 72 h, the guidelines recommend the use of high-dose amoxicillin-clavulanate in two divided doses, in a 14:1 formulation (90 mg/amoxicillin component to a 6.4 mg/clavulin component). The addition of clavulanate is effective against the beta-lactamase-producing strains of H influenzae or Moraxella catarrhalis, which are thought to be the pathogens responsible for disease in those who fail initial amoxicillin treatment. Because this formulation is not available in Canada, one may prescribe the 7:1 Clavulin (GlaxoSmithKline Inc, Canada) product containing 45 mg/kg/day of the amoxicillin component and an additional amoxicillin dose of 45 mg/kg/day for a combined total of 90 mg/kg/day of amoxicillin. Clavulin-200 and -400 suspensions (7:1) are given every 12 h (6). If this treatment fails, the guidelines recommend a three-day course of parenteral ceftriaxone, owing to its superior efficacy against S pneumoniae compared with the oral antibiotics.

What is new in otitis media?

The “wait and see” approach in acute otitis media (AOM), consisting of postponing the antibiotic administration for a few days, has been advocated mainly to counteract the increased bacterial resistance in respiratory infections. This approach is not justified in children less than 2 years of age and this for several reasons. First, AOM is an acute inflammation of the middle ear caused in about 70% of cases by bacteria. Redness and bulging of the tympanic membrane are characteristic findings in bacterial AOM. Second, AOM is associated with long-term dysfunction of the inflamed eustachian tube (ET), particularly in children less than 2 years of age. In this age group, the small calibre of the ET together with its horizontal direction result in impaired clearance, ventilation and protection of the middle ear. Third, recent prospective studies have shown poor long-term prognosis of AOM in children below 2 years with at least 50% of recurrences and persisting otitis media with effusion (OME) in about 35% 6 months after AOM. Viruses elicit AOM in about 30% of children. A prolonged course of AOM has been observed when bacterial and viral infections are combined because viral infection is also associated with ET dysfunction in young children. Bacterial and viral testing of the nasopharyngeal aspirate is an excellent tool both for initial treatment and recurrence of AOM. Antibiotic treatment of AOM is mandatory in children less than 2 years of age to decrease inflammation in the middle ear but also of the ET particularly during the first episode. The best choice is amoxicillin because of its superior penetration in the middle ear. Streptococci pneumoniae with intermediary bacterial resistance to penicillin are particularly associated with recurrent AOM. Therefore the dosage of amoxicillin should be 90 mg/kg per day in three doses. In recurrent AOM with β-lactamase-producing bacilli, amoxicillin should be associated with clavulanic acid at a dose of 6.4 mg/kg per day. The duration of the treatment is not established yet but 10 days is reasonable for a first episode of AOM. OME may be a precursor initiating AOM but also a complication thereof. OME needs a watchful waiting approach. When associated with deafness for 2–3 months in children over 2 years of age, an antibiotic should be given according to the results of the bacterial resistance in the nasopharyngeal aspirate. The high rate of complications of tympanostomy tube insertion outweighs the beneficial effect on hearing loss. The poor results of this procedure are due to the absence of effects on ET dysfunction. Pneumococcal vaccination has little beneficial effects on recurrent AOM and its use in infants needs further studies. Treatment with amoxicillin is indicated in all children younger than 2 years with a first episode of AOM presenting with redness and bulging of the tympanic membrane. Combined amoxicillin and clavulanic acid should be given in patients with β-lactamase-producing bacteria. The duration of treatment is estimated to be at least 10 days depending on the findings by pneumo-otoscopy and tympanometry. Bacterial and viral testing of the nasopharyngeal aspirate is highly recommended particularly in children in day care centres as well as for regular follow-up. The high recurrence rate is due to the long-lasting dysfunction of the eustachian tube and the immune immaturity of children less than 2 years of age.

Acute otitis media and pneumococcal resistance: making judicious management decisions.

The emergence of drug-resistant Streptococcus pneumoniae (DRSP) has implications for the primary care provider who treats acute otitis media (AOM) in children. AOM must be carefully distinguished from otitis media with effusion (OME). Antibiotic treatment for AOM is recommended because of the low rate of spontaneous resolution of S. pneumoniae infection and the risk of suppurative complications, particularly in young children. Amoxicillin continues to be the first drug of choice. Children for whom the first course of antibiotics fails should be treated with amoxicillin-clavulanate, cefuroxime axetil, or ceftriaxone. Trimethoprim-sulfamethoxazole, the macrolides, and most of the cephalosporins have limited effectiveness against DRSP and should no longer have a major role in AOM treatment. OME need not be treated with antibiotics unless the effusion has been present for 3 to 4 months. Tympanostomy tubes are an effective treatment for both chronic OME and recurrent AOM. Given the significant increase of DRSP during the past decade, clinicians must minimize antibiotic use and, when antibiotics are required, make judicious clinical decisions.

Intratemporal and intracranial complications of acute suppurative otitis media in children: renewed interest

In recent years, a rise in the incidence of intratemporal and intracranial complications of acute otitis media (AOM) has been mentioned in the literature. Lack of a well-developed immune system and difficulties in diagnosing AOM, can account for part of the rise in the incidence of complications of purulent middle ear infections in young children. Antibiotic treatment of AOM is certainly not an absolute safeguard against the development of complications. Antibiotic therapy may have a masking effect on significant signs and symptoms of complications, causing delay in diagnosis. Myringotomy, especially in young children, should not be forgotten for drainage and to provide material for culture. Increased virulence of the causative pathogens cannot be ruled out, but to date there is no evidence suggesting it. We have to maintain a high level of clinical awareness. If there is insufficient improvement of the patient with the appropriate conservative treatment, radioimaging followed by the necessary surgical procedures should be performed.

Dynamics of pneumococcal nasopharyngeal colonization during the first days of antibiotic treatment in pediatric patients.

Nasopharyngeal (NP) carriage of antibiotic-resistant Streptococcus pneumoniae was shown to be associated with recent antibiotic treatment. To date no studies have evaluated early dynamics of pneumococcal NP carriage during antibiotic treatment. To observe changes in NP pneumococcal carriage within 3 to 4 days after initiation of antibiotic treatment in acute otitis media (AOM). Patients ages 3 to 36 months with AOM treated with various antibiotics were prospectively followed. Nasopharyngeal culture for S. pneumoniae was obtained before (Day 1) and 72 to 96 h after initiation of treatment (Days 4 to 5). Antibiogram and serotyping were performed in all isolates as was also the MIC of penicillin. The disappearance and persistence of the initial isolates as well as the appearance of isolates with new serotype or with new antibiotic susceptibility patterns were investigated. A total of 120 patients were studied: 106 received beta-lactam antibiotics and 14 received azithromycin. Among the initial 76 pneumococcal isolates 63, 37 and 13% were resistant to > or =1, > or =2 and > or =3 antibiotic drugs. After 3 to 4 days of treatment with various beta-lactam drugs, 45, 63 and 100% of isolates with MIC values of <0.1 microg/ml, 0.125 to 0.25 microg/ml and 0.38 to 1.0 microg/ml, respectively, persisted in the NP (P = 0.038). There was a difference between the various beta-lactam drugs in their effect on NP colonization: a drug with lower MIC values (cefuroxime-axetil) had a better eradication rate of penicillin-susceptible organisms than a less active one (cefaclor), but neither significantly reduced carriage of penicillin nonsusceptible isolates. Azithromycin eliminated carriage of macrolide-susceptible organisms but increased the carriage of macrolide-resistant ones. In 19 of 120 (16%) patients a new S. pneumoniae isolate was recovered 3 to 4 days after initiation of treatment. Of those 16 (84%) were resistant to the drug the patient was receiving. A rapid selection of nonsusceptible NP pneumococcal isolates during antibiotic treatment for AOM is common. This phenomenon may contribute to the spread of resistant pneumococci.