Azithromycin versus penicillin V for treatment of acute group A streptococcal pharyngitis

Group A β-hemolytic Streptococcal Pharyngitis: An Updated Review

BACKGROUND

Group A ß-hemolytic Streptococcus (GABHS) is the leading bacterial cause of acute pharyngitis in children and adolescents worldwide.

OBJECTIVE

This article aims to familiarize clinicians with the clinical manifestations, evaluation, diagnosis, and management of GABHS pharyngitis.

METHODS

A search was conducted in December 2022 in PubMed Clinical Queries using the key term "group A β-hemolytic streptococcal pharyngitis". This review covers mainly literature published in the previous ten years.

RESULTS

Children with GABHS pharyngitis typically present with an abrupt onset of fever, intense pain in the throat, pain on swallowing, an inflamed pharynx, enlarged and erythematous tonsils, a red and swollen uvula, enlarged tender anterior cervical lymph nodes. As clinical manifestations may not be specific, even experienced clinicians may have difficulties diagnosing GABHS pharyngitis solely based on epidemiologic or clinical grounds alone. Patients suspected of having GABHS pharyngitis should be confirmed by microbiologic testing (e.g., culture, rapid antigen detection test, molecular point-of-care test) of a throat swab specimen prior to the initiation of antimicrobial therapy. Microbiologic testing is generally unnecessary in patients with pharyngitis whose clinical and epidemiologic findings do not suggest GABHS. Clinical score systems such as the Centor score and McIssac score have been developed to help clinicians decide which patients should undergo diagnostic testing and reduce the unnecessary use of antimicrobials. Antimicrobial therapy should be initiated without delay once the diagnosis is confirmed. Oral penicillin V and amoxicillin remain the drugs of choice. For patients who have a non-anaphylactic allergy to penicillin, oral cephalosporin is an acceptable alternative. For patients with a history of immediate, anaphylactic-type hypersensitivity to penicillin, oral clindamycin, clarithromycin, and azithromycin are acceptable alternatives.

CONCLUSION

Early diagnosis and antimicrobial treatment are recommended to prevent suppurative complications (e.g., cervical lymphadenitis, peritonsillar abscess) and non-suppurative complications (particularly rheumatic fever) as well as to reduce the severity of symptoms, to shorten the duration of the illness and to reduce disease transmission.

Examining the Efficacy of Antimicrobial Therapy in Preventing the Development of Postinfectious Glomerulonephritis: A Systematic Review and Meta-Analysis

Postinfectious glomerulonephritis (PIGN) is an immune-mediated acute glomerulonephritis classically seen weeks after infection with Streptococcus pyogenes, although other infectious etiologies have emerged. While it has become increasingly rare in industrialized regions, it continues to affect children in developing countries. There has been debate as to why incidence rates are declining, including the possibility of improved initial treatment of bacterial infections. The ability of antimicrobial therapy in preventing PIGN as infectious sequelae, however, has not been comprehensively assessed. As varying evidence from published studies exists, the objective of this meta-analysis is to determine if antimicrobial therapy utilized to treat an initial infection has an effect in reducing the development of PIGN in humans. EMBASE, MEDLINE, and CENTRAL were searched using a comprehensive terminology strategy. From an initial search that returned 337 publications, 9 articles were included for analysis. Eight studies showed an incidence of PIGN after antimicrobial use ranging from 0.05% to 10% with a mean standardized difference (MSD) of 0.03 (0.01–0.06). Three studies showed an occurrence of PIGN without antibiotic use ranging from 1% to 13% with an MSD of 0.06 (−0.09–0.21). Our findings suggest that antimicrobial treatment for the initial infection may help diminish the development of PIGN. Although Streptococcus pyogenes infections are generally treated aggressively to prevent rheumatic fever, these findings may help further support the early treatment of bacterial infections to prevent postinfectious sequelae, especially as we consider other infectious etiologies of PIGN antimicrobial resistance.

Short- vs. Long-Course Antibiotic Treatment for Acute Streptococcal Pharyngitis: Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

To evaluate the effectiveness of short courses of antibiotic therapy for patients with acute streptococcal pharyngitis.

METHODS

Randomized controlled trials comparing short-course antibiotic therapy (≤5 days) with long-course antibiotic therapy (≥7 days) for patients with streptococcal pharyngitis were included. Two primary outcomes: early clinical cure and early bacterial eradication.

RESULTS

Fifty randomized clinical trials were included. Overall, short-course antibiotic treatment was as effective as long-course antibiotic treatment for early clinical cure (odds ratio (OR) 0.85; 95% confidence interval (CI) 0.79 to 1.15). Subgroup analysis showed that short-course penicillin was less effective for early clinical cure (OR 0.43; 95% CI, 0.23 to 0.82) and bacteriological eradication (OR 0.34; 95% CI, 0.19 to 0.61) in comparison to long-course penicillin. Short-course macrolides were equally effective, compared to long-course penicillin. Finally, short-course cephalosporin was more effective for early clinical cure (OR 1.48; 95% CI, 1.11 to 1.96) and early microbiological cure (OR 1.60; 95% CI, 1.13 to 2.27) in comparison to long-course penicillin. In total, 1211 (17.7%) participants assigned to short-course antibiotic therapy, and 893 (12.3%) cases assigned to long-course, developed adverse events (OR 1.35; 95% CI, 1.08 to 1.68).

CONCLUSIONS

Macrolides and cephalosporins belong to the list of "Highest Priority Critically Important Antimicrobials"; hence, long-course penicillin V should remain as the first line antibiotic for the management of patients with streptococcal pharyngitis as far as the benefits of using these two types of antibiotics do not outweigh the harms of their unnecessary use.

Short-term late-generation antibiotics versus longer term penicillin for acute streptococcal pharyngitis in children

BACKGROUND

The standard duration of treatment for children with acute group A beta hemolytic streptococcus (GABHS) pharyngitis with oral penicillin is 10 days. Shorter duration antibiotics may have comparable efficacy.

OBJECTIVES

To summarize the evidence regarding the efficacy of two to six days of newer oral antibiotics (short duration) compared to 10 days of oral penicillin (standard duration) in treating children with acute GABHS pharyngitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2012, Issue 3) which contains the Cochrane Acute Respiratory Infections Group's Specialized Register, MEDLINE (January 1966 to March week 3, 2012) and EMBASE (January 1990 to April 2012).

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing short duration oral antibiotics to standard duration oral penicillin in children aged 1 to 18 years with acute GABHS pharyngitis.

DATA COLLECTION AND ANALYSIS

Two review authors scanned the titles and abstracts of retrieved citations and applied the inclusion criteria. We retrieved included studies in full, and extracted data. Two review authors independently assessed trial quality.

MAIN RESULTS

We included 20 studies with 13,102 cases of acute GABHS pharyngitis. The updated search did not identify any new eligible studies; the majority of studies were at high risk of bias. However, the majority of the results were consistent. Compared to standard duration treatment, the short duration treatment studies had shorter periods of fever (mean difference (MD) -0.30 days, 95% confidence interval (CI) -0.45 to -0.14) and throat soreness (MD -0.50 days, 95% CI -0.78 to -0.22); lower risk of early clinical treatment failure (odds ratio (OR) 0.80, 95% CI 0.67 to 0.94); no significant difference in early bacteriological treatment failure (OR 1.08, 95% CI 0.97 to 1.20) or late clinical recurrence (OR 0.95, 95% CI 0.83 to 1.08). However, the overall risk of late bacteriological recurrence was worse in the short duration treatment studies (OR 1.31, 95% CI 1.16 to 1.48), although no significant differences were found when studies of low dose azithromycin (10 mg/kg) were eliminated (OR 1.06, 95% CI 0.92 to 1.22). Three studies reported long duration complications. Out of 8135 cases of acute GABHS pharyngitis, only six cases in the short duration treatment versus eight in the standard duration treatment developed long-term complications in the form of glomerulonephritis and acute rheumatic fever, with no statistically significant difference (OR 0.53, 95% CI 0.17 to 1.64).

AUTHORS' CONCLUSIONS

Three to six days of oral antibiotics had comparable efficacy compared to the standard duration 10-day course of oral penicillin in treating children with acute GABHS pharyngitis. . In areas where the prevalence of rheumatic heart disease is still high, our results must be interpreted with caution.

Once weekly azithromycin in secondary prevention of rheumatic fever

Rheumatic fever and rheumatic heart disease (RHD) are still important problems in developing countries. Secondary prophylaxis which is the most cost-effective method in preventing recurrences of rheumatic fever is fraught with problems of drug compliance. The utility of 500 mg once weekly azithromycin (AZT), an orally effective long-acting antibiotic was evaluated against oral penicillin (phenoxy methyl penicillin 250 mg twice daily) in this study. Forty-eight consecutive patients (44% males, mean age 29.4 years) with established RHD were randomised into two groups-26 patients received AZT and 22 received oral penicillin. Patients were evaluated at randomisation, at 1 month, 3 months, and 6 months, clinically, serologically and by throat swab culture. End points were absence of streptococcal colonisation, infection or fever at the end of 6 months. During the study, 4 patients (15.4%) in the AZT group developed sore throat and fever, had positive throat culture and positive serology indicating streptococcal infection. None satisfied the criteria for rheumatic fever reactivation. None in the oral penicillin group developed streptococcal infection. In conclusion, weekly 500 mg of AZT is not effective in the prevention of streptococcal throat infection compared to oral penicillin therapy in adult patients with established RHD.

Genetic commonality of macrolide-resistant group A beta hemolytic streptococcus pharyngeal strains

Background

Group A beta hemolytic streptococcus (GABHS) pharyngitis is a common childhood illness. Penicillin remains the gold standard therapy, but macrolides are indicated for the penicillin allergic patient, and are often used for convenience.

Methods

We conducted a surveillance study of children with pharyngitis and positive streptococcal rapid antigen testing from 10/05 to 10/06 at 2 sites (A & B). Demographics, treatment, and resistance data was collected and compared to previous data from 2002. Erythromycin (EM) resistance was determined by disk diffusion and E-test on 500 isolates. Pulse field gel electrophoresis (PFGE) was performed to measure genetic relatedness of isolates. StatXact version 8 software (Cytel Inc., Cambridge, MA) was utilized to perform Fisher's exact test and exact confidence interval (CI) analysis.

Results

There were no differences in resistance rates or demographic features, with the exception of race, between sites A & B. EM resistance was 0 in 2002, 3.5% in 2005-06 at site A, and 4.5% in 2005-06 at site B. 3/7 and 3/9 had inducible resistance at A and B respectively. 8 isolates had relatedness ≥80%, 5 of which were 88% homologous on PFGE.

Conclusion

Community macrolide resistance has increased following increased macrolide use. These results may have treatment implications if use continues to be high.

Short versus standard duration antibiotic therapy for acute streptococcal pharyngitis in children

BACKGROUND

The standard duration of treatment for acute group A beta hemolytic streptococcus (GABHS) pharyngitis with oral penicillin is 10 days. Shorter duration antibiotics may have comparable efficacy.

OBJECTIVES

To summarize the evidence regarding the efficacy of two to six days of newer oral antibiotics (short duration) compared to 10 days of oral penicillin (standard duration) in treating children with acute GABHS pharyngitis.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, issue 4), which contains the Acute Respiratory Infections Group's Specialized Register; the Database of Abstracts of Reviews of Effects (DARE); MEDLINE (1966 to October 2007); OLDMEDLINE (1950 to December 1965); and EMBASE (January 1990 to November 2007).

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing short duration oral antibiotics to standard duration oral penicillin in children aged 1 to 18 years with acute GABHS pharyngitis.

DATA COLLECTION AND ANALYSIS

Two review authors scanned the titles and abstracts of retrieved citations and applied the inclusion criteria. We retrieved included studies in full and extracted data. Two review authors independently assessed trial quality.

MAIN RESULTS

Twenty studies were included with 13,102 cases of acute GABHS pharyngitis. Compared to standard duration treatment, the short duration treatment had shorter periods of fever (mean difference (MD) -0.30 days, 95% CI -0.45 to -0.14) and throat soreness (MD -0.50 days, 95% CI -0.78 to -0.22); lower risk of early clinical treatment failure (OR 0.80, 95% CI 0.67 to 0.94); no significant difference in early bacteriological treatment failure (OR 1.08, 95% CI 0.97 to 1.20), or late clinical recurrence (OR 0.95, 95% CI 0.83 to 1.08). However, the overall risk of late bacteriological recurrence was worse in the short duration treatment (OR 1.31, 95% CI 1.16 to 1.48), although no significant differences were found when studies of low dose azithromycin (10mg/kg) were eliminated (OR 1.06, 95% CI 0.92 to 1.22). Three studies reported long duration complications with no statistically significant difference (OR 0.53, 95% CI 0.17 to 1.64).

AUTHORS' CONCLUSIONS

Three to six days of oral antibiotics had comparable efficacy compared to the standard duration 10 day oral penicillin in treating children with acute GABHS pharyngitis. In countries with low rates of rheumatic fever, it appears safe and efficacious to treat children with acute GABHS pharyngitis with short duration antibiotics. In areas where the prevalence of rheumatic heart disease is still high, our results must be interpreted with caution.

Clinical efficacy of dexamethasone for acute exudative pharyngitis

The objective of this study was to investigate whether treatment with single-dose dexamethasone can provide relief of symptoms in acute exudative pharyngitis. A prospective, randomized, double-blinded, placebo-controlled clinical trial was undertaken over a 3-month period in a university-based Emergency Department. The study included all consecutive patients between 18 and 65 years of age presenting with acute exudative pharyngitis, sore throat, odynophagia, or a combination, and with more than two Centor criteria. Each patient was empirically treated with azithromycin and paracetamol for 3 days. The effects of placebo and a fixed single dose (8 mg) of intramuscular injection of dexamethasone were compared. The patients were asked to report the exact time to onset of pain relief and time to complete relief of pain. After completion of the treatment, telephone follow-up regarding the relief of pain was conducted. A total of 103 patients were enrolled. Thirty patients with a history of recent antibiotic use, pregnancy, those who were elderly (>65 years of age) and patients who failed to give informed consent were excluded. Forty-two patients were assigned to the placebo group and 31 were assigned to the intramuscular dexamethasone group (8-mg single dose). Time to perceived onset of pain relief was 8.06+/-4.86 h in steroid-treated patients, as opposed to 19.90+/-9.39 h in the control group (p=0.000). The interval required to become pain-free was 28.97+/-12.00 h in the dexamethasone group, vs. 53.74+/-16.23 h in the placebo group (p=0.000). No significant difference was observed in vital signs between the regimens. No side effects and no new complaints attributable to the dexamethasone and azithromycin were observed. Sore throat and odynophagia in patients with acute exudative pharyngitis may respond better to treatment with an 8-mg single dose of intramuscular dexamethasone accompanied by an antibiotic regimen than to antibiotics alone.

Airway infectious disease emergencies

Upper and lower respiratory infections are encountered commonly in the emergency department. Visits resulting from occurrences of respiratory disease account for 10% of all pediatric emergency department visits and 20% of all pediatric hospital admissions. Causes of upper airway infections include croup, epiglottitis, retropharyngeal abscess, cellulitis, pharyngitis, and peritonsillar abscesses. Lower airway viral and bacterial infections cause illnesses such as pneumonia and bronchiolitis. Signs and symptoms of upper and lower airway infections overlap, but the differentiation is important for appropriate treatment of these conditions. This article reviews the varied clinical characteristics of upper and lower airway infections.

Higher Dosages of Azithromycin Are More Effective in Treatment of Group A Streptococcal Tonsillopharyngitis

BACKGROUND

Azithromycin has become a frequent choice for the treatment of group A streptococcal (GAS) tonsillopharyngitis. In this study, our objective was to determine the optimal dose of azithromycin for treatment of GAS tonsillopharyngitis in children and adults by analyzing trials that used different dose regimens.

METHODS

We performed a meta-analysis of randomized, controlled trials that involved bacteriological confirmation of GAS tonsillopharyngitis, random assignment to receive either azithromycin or a 10-day comparator antibiotic, and assessment of bacteriological eradication by throat culture after therapy. The primary outcomes of interest were bacteriological and clinical cure rates.

RESULTS

Nineteen trials involving 4626 patients were included in the analysis. One trial used 10-day course of 2 different comparator antibiotics, and 2 trials compared 2 dose regimens of azithromycin with a 10-day course of comparator antibiotic; all other trials compared 1 dose regimen of azithromycin with a single 10-day course of comparator antibiotic. In children, azithromycin administered at 60 mg/kg per course was superior to the 10-day courses of comparators (P < .00001), with bacterial failure occurring 5 times more often in patients receiving the 10-day courses of antibiotics. Azithromycin administered at 30 mg/kg per course was inferior to the 10-day courses of comparators (P = .02), with bacterial failure occurring 3 times more frequently in patients receiving azithromycin. Three-day regimens were inferior to 5-day regimens (P = .002). In adults, no studies compared dosages by weight. Three-day regimens of 500 mg/day showed a trend favoring azithromycin over the 10-day courses of comparators (P = .14); 5-day regimens were inferior to 3-day regimens (P = .006). Clinical cure rates were significantly different for the different azithromycin regimens, with differences that resembled those for bacterial cure rate.

CONCLUSION

This analysis suggests that azithromycin administered at a dosage of 60 mg/kg in children or administered for 3 days at a dosage of 500 mg/day in adults is more effective than other treatment regimens in producing eradication and clinical cure of GAS tonsillopharyngitis.

Group A beta-hemolytic streptococcal pharyngitis in children

Group A beta-hemolytic streptococcus (GABHS) is the most common bacterial cause of acute pharyngitis in children. Because clinical findings can be nonspecific, even experienced physicians cannot reliably diagnose GABHS pharyngitis solely on the basis of clinical presentation. Suspected cases should be confirmed by a throat culture or a rapid antigen detection test before antibiotic therapy is initiated. Microbiologic testing is generally not necessary in patients with pharyngitis whose clinical and epidemiologic findings are not suggestive of GABHS. Clinical score systems have been developed to help physicians decide which patients should undergo diagnostic testing and to reduce the unnecessary use of antibiotics. Antibiotic therapy should be initiated as soon as the diagnosis is confirmed. Penicillin V remains the drug of choice. Alternative therapy, e.g., with cephalosporin or macrolide, is often sought because of penicillin allergy, noncompliance, and treatment failure.

Decrease in antibiotic use among children in the 1990s: not all antibiotics, not all children

BACKGROUND

Decreases in antibiotic use were widely reported in the 1990s. This study was undertaken to determine trends in the use of antibiotics from fiscal year (FY) 1995 (April 1995 to March 1996) to FY 2001 in a complete population of Manitoba children.

METHODS

Using Manitoba's health care databases, we determined annual population-based rates of antibiotic prescription among children by antibiotic class (narrow-spectrum and broader-spectrum antibiotics), age group, physician diagnosis (e.g., otitis media or bronchitis) and neighbourhood income in urban areas (derived from the 1996 census). Antibiotic prescription rates were generated within a generalized linear model framework with general estimating equations, and differences between FY 2001 and FY 1995 were tested. Differences in antibiotic use over time were compared across antibiotic classes, age groups, diagnoses and income neighbourhoods.

RESULTS

The overall antibiotic prescription rate decreased by almost one-third, from 1.2 prescriptions per child in FY 1995 to 0.9 prescriptions in FY 2001. Total antibiotic use declined for all respiratory tract infections; decreases were greatest for the sulfonamides (decrease to less than one-third the FY 1995 rate) and narrow-spectrum macrolides (decrease to less than half the FY 1995 rate). In contrast, the FY 2001 rate for broader-spectrum macrolides was as much as 12.5 times the FY 1995 rate. Otitis media accounted for one-quarter of the use of the latter agents. Preschool children and low-income children received the greatest number of antibiotic prescriptions. Declines in antibiotic prescriptions were of a lesser magnitude for low-income children (for whom rates in FY 2001 were four-fifths the rates in FY 1995) than for higher-income children (for whom rates in FY 2001 were about two-thirds the rates in FY 1995).

INTERPRETATION

Overall, antibiotic use declined over the late 1990s in this population of Canadian children, but the increasing use of broader-spectrum macrolides and higher rates of antibiotic use among preschool and low-income children may have implications for antibiotic resistance.

Evidence-based prescribing of antibiotics for children: role of socioeconomic status and physician characteristics

BACKGROUND

Evidence-based guidelines for antibiotic use are well established, but nonadherence to these guidelines continues. This study was undertaken to determine child, household and physician factors predictive of nonadherence to evidence-based antibiotic prescribing in children.

METHODS

The prescription and health care records of 20 000 Manitoba children were assessed for 2 criteria of nonadherence to evidence-based antibiotic prescribing during the period from fiscal year 1996 (April 1996 to March 1997) to fiscal year 2000: receipt of an antibiotic for a viral respiratory tract infection (VRTI) and initial use of a second-line agent for acute otitis media, pharyngitis, pneumonia, urinary tract infection or cellulitis. The likelihood of nonadherence to evidence-based prescribing, according to child demographic characteristics, physician factors (specialty and place of training) and household income, was determined from hierarchical linear modelling. Child visits were nested within physicians, and the most parsimonious model was selected at p < 0.05.

RESULTS

During the study period, 45% of physician visits for VRTI resulted in an antibiotic prescription, and 20% of antibiotic prescriptions were for second-line antibiotics. Relative to general practitioners, the odds ratio for antibiotic prescription for a VRTI was 0.51 (95% confidence interval [CI] 0.42-0.62) for pediatricians and 1.58 (95% CI 1.03-2.42) for other specialists. The likelihood that an antibiotic would be prescribed for a VRTI was 0.99 for each successive 10,000 Canadian dollars increase in household income. Pediatricians and other specialists were more likely than general practitioners to prescribe second-line antibiotics for initial therapy. Both criteria for nonadherence to evidence-based prescribing were 40% less likely among physicians trained in Canada or the United States than among physicians trained elsewhere.

INTERPRETATION

The links that we identified between nonadherence to evidence-based antibiotic prescribing in children and physician specialty and location of training suggest opportunities for intervention. The independent effect of household income indicates that parents also have an important role.

Short-course antimicrobial therapy of respiratory tract infections

Accumulating evidence suggests that short-course (</=5 days, </=3 days for azithromycin) antimicrobial therapy may be at least as effective as and, in some cases, may be more effective than traditional longer (10- to 14-day) therapies. In group A beta-haemolytic streptococcal tonsillopharyngitis, short-course therapy with 6 days of amoxicillin, 4-5 days of a variety of cephalosporins and 5 days of clarithromycin modified-release and telithromycin are all reasonable alternatives to traditional 10-day penicillin therapy. Short-course (i.e. 3-day) azithromycin therapy is not recommended because of suboptimal clinical and bacteriological results compared with penicillin therapy, unless the dosage is doubled from 10 to 20 mg/kg/day for all 3 days. In uncomplicated acute suppurative otitis media, single-dose intramuscular ceftriaxone or 3- to 5-day short-course oral antimicrobial therapy should be effective in the majority (>/=80%) of patients. However, more research is clearly needed in the subpopulations of children <2 years of age and in those with unresponsive/recurrent disease, since short-course therapy may not be successful in the majority of these patients. In sinusitis, most short-course therapy data have involved maxillary disease in adult patients. Regimens have included 3 days of azithromycin or cotrimoxazole (trimethoprim/sulfamethoxazole) or 5 days of cefpodoxime, telithromycin, gatifloxacin, gemifloxacin or amoxicillin/clavulanic acid. Preliminary results are encouraging but more study is clearly needed, especially in the paediatric population. In acute bacterial exacerbations of chronic bronchitis, short-course therapy with a variety of cephalosporins, second-generation fluoroquinolones and advanced generation macrolides/azalides/ketolides are all reasonable alternatives to traditional 7- to 14-day therapies. Cost containment in antimicrobial therapy should involve consideration of short-course therapy in the management of the most common types of respiratory tract infections.

Safety and tolerability of azithromycin in pediatric infectious diseases: 2003 update

Oral azithromycin suspension has been prescribed to >80 million patients. Children find the color and taste of the oral suspension of azithromycin agreeable, and the drug is well-tolerated. On average 9% of patients have treatment-related adverse events, which are most frequently gastrointestinal complaints. The side effects are mild to moderate and very seldom necessitate withdrawal of the treatment. In addition to the conventional 3-day 10-mg/kg/day regimen and the 10 mg/kg on Day 1 followed by 5 mg/kg on Days 2 to 5 regimens, single dose 30 mg/kg and 3-day 20-mg/kg/day regimens are well-tolerated, although these new dosages are associated with more adverse effects.

Acute Streptococcal Tonsillopharyngitis: A Review of Clinical Efficacy and Bacteriological Eradication

This review evaluates studies published between January 1997 and August 2003 comparing clinical outcome and bacteriological eradication rates for patients with acute streptococcal tonsillopharyngitis treated with penicillin or other antimicrobial agents. Studies were identified using MEDLINE, and clinical outcome and bacteriological eradication at end of treatment and 2 weeks after end of treatment were ascertained. Any longer-term follow-up was also noted, along with treatment-related adverse events and compliance. Clinical efficacy rates between penicillin and comparator antibiotics were generally high and similar. Bacterial eradication rates were more variable and, 2 weeks after treatment, ranged from 64% to 93% for penicillin and 31% to 98% for comparators. Simpler dosing schedules and shorter therapy durations produced higher compliance rates. This review highlights the similarities and differences between treatment with penicillin and a wide range of comparator antibiotics. Therapy for acute group A streptococcal pharyngitis should combine excellent clinical efficacy, high bacteriological eradication rates, good tolerance and a simple, convenient dosing regimen.

Defining the optimum treatment regimen for azithromycin in acute tonsillopharyngitis

Pharyngitis is one of the most common infectious diseases affecting children. Group A streptococci are the leading bacterial cause of pharyngitis in children and adults. Because inappropriate antibiotic treatment for pharyngitis is becoming a major issue, only true group A beta-hemolytic streptococcus (GABHS) infections, proven by rapid antigen test or culture, should be treated with antibiotics. GABHS pharyngitis is often a mild and self-limiting infection in the absence of antimicrobial therapy. However, antimicrobial treatment must be administered to eradicate the pathogen from the throat, limit the spread of the infection and prevent possible progression to rheumatic fever, suppurative disease or toxin-mediated complications. Penicillin V for 10 days is the standard therapy and is effective in the management of GABHS pharyngitis. However, there are drawbacks to penicillin V therapy, including the length of the dosing regimen, which are leading to decreasing penicillin prescription rates in many countries. In addition bacteriologic treatment failures have been documented in up to 35% of GABHS patients treated with penicillin V, particularly in children <6 years old. A number of mechanisms may be responsible for these failures, but poor compliance with the standard 10-day penicillin treatment is likely to be a major factor. There is growing evidence to suggest that children with GABHS pharyngitis can be effectively treated with non-penicillin V antibiotics, which have the advantage of simpler and shorter dosing regimens compared with penicillin V. Among the antibiotics that have been tested clinically, azithromycin is the most widely studied. A total dose of 60 mg/kg azithromycin, given either as 12 mg/kg once daily for 5 days or 20 mg/kg once daily for 3 days, provides the best rate of GABHS eradication. Thus a total dose of 60 mg/kg azithromycin given during 3 or 5 days constitutes an alternative treatment to standard penicillin therapy in cases of penicillin hypersensitivity, when patient nonadherence to a 10-day penicillin regimen is suspected or for patients who fail therapy with a beta-lactam.

Short-course antimicrobial therapy of streptococcal pharyngitis

While penicillin administered orally or intramuscularly is the least expensive course of pharyngitis treatment, there are many limitations to its use. These include the need for extended treatment (i.e., 10 days) and poor palatability of its liquid formulation and an alarming increase in the rates of failure with standard doses of either IM or oral penicillin. Increasing rates of beta-lactamase-producing normal flora and eradication of protective alpha-streptococci may also play a role in penicillin treatment failure. Thus practitioners may consider switching to amoxicillin in higher doses (up to 40 to 60 mg/kg/day divided twice daily, maximum dose 1 gram twice daily) as first-line therapy (Figure 1), similar to what we have done for acute otitis media. Five-day short-course treatment with cefdinir or cefpodoxime may be suitable alternatives, especially in patients with penicillin hypersensitivity (not anaphylaxis). Concerns with higher costs of these second-line agents and potential for resistance must be balanced with concerns for patient adherence with penicillin treatment and the recent increasing rate of penicillin failures. In light of recent reports regarding the high rate of failure with azithromycin and increasing macrolide resistance, clinicians should prescribe standard doses of this drug for 5 days with caution.