Azithromycin compared with clarithromycin for the treatment of streptococcal pharyngitis in children

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.

Impact of oseltamivir use on the reduction of complications in patients with influenza: a prospective study

To evaluate the factors associated with oseltamivir prescription and to study the effectiveness of oseltamivir in reducing influenza-related complications. A prospective cohort study using the SOS Doctors (a network of physicians who perform house-call visits in Attica, Greece). Patients with confirmed or clinically suspected influenza were followed up to 14 days during the 2011-2012 influenza period. 410 patients with confirmed or suspected influenza were included. Healthy adults were mainly enrolled, with a median age of 44 years. Influenza diagnosis was mainly based on clinical criteria (65.8 % of patients). Oseltamivir was prescribed for 45.4 % of them. In a multivariate analysis, prescription of oseltamivir was associated with the attending physician (p < 0.001), positive influenza test (p < 0.001) and diabetes (p = 0.027). Data on complications were available for 351 patients, and 50 (15.8 %) of them reported at least one. Seven patients required hospitalization. Types of complications (pneumonia, bronchitis, etc.) were not significantly different between patients receiving and those not receiving oseltamivir. In the multivariate analysis, higher oseltamivir prescription rate was associated with fewer complications (p < 0.001). Bearing in mind the limitations of a non-randomized study, in a real-life setting, oseltamivir prescription and the rate of complications in patients with influenza were associated with the attending physician, underlying diseases and diagnostic tests. Overall, when the frequency of oseltamivir prescription increased, the influenza-related complications decreased.

Compliance with once-daily versus twice or thrice-daily administration of antibiotic regimens: a meta-analysis of randomized controlled trials

Objective

To investigate whether compliance of patients to antibiotic treatment is better when antibiotics are administered once than multiple times daily.

Methods

We performed a systematic search in PubMed and Scopus databases. Only randomized controlled trials were considered eligible for inclusion. Compliance to antibiotic treatment was the outcome of the meta-analysis.

Results

Twenty-six studies including 8246 patients with upper respiratory tract infections in the vast majority met the inclusion criteria. In total, higher compliance was found among patients treated with once-daily treatment than those receiving treatment twice, thrice or four times daily [5011 patients, RR=1.22 (95% CI, 1.11, 1.34]. Adults receiving an antibiotic once-daily were more compliant than those receiving the same antibiotic multiple times daily [380 patients, RR=1.09 (95% CI, 1.02, 1.16)]. Likewise, children that received an antibiotic twice-daily were more compliant than those receiving the same antibiotic thrice-daily [2118 patients, RR=1.10 (95% CI, 1.02, 1.19)]. Higher compliance was also found among patients receiving an antibiotic once compared to those receiving an antibiotic of different class thrice or four times daily [395 patients, RR=1.20 (95% CI, 1.12, 1.28)]. The finding of better compliance with lower frequency daily was consistent regardless of the study design, and treatment duration.

Conclusion

This meta-analysis showed that compliance to antibiotic treatment might be associated with higher when an antibiotic is administered once than multiple times daily for the treatment of specific infections and for specific classes of antibiotics.

Non-compliance with antibiotic therapy for acute community infections: a global survey

A global patient survey of non-compliance with antibiotic therapy for acute community infections included 4514 adult respondents (aged 18-99 years) in 11 countries. Admitted non-compliance (ANC) was reported in 912/4088 (22.3%) of cases but varied widely between countries. Multivariate analysis identified five independent variables associated with ANC: country, daily dosage regimen, age, attitudes to doctors and attitudes to antibiotics. ANC ranged from 44.0% in China to 9.9% in The Netherlands, and from 14.9% in those prescribed once-daily regimens to 27.0% for three or more daily doses. There was a negative correlation between ANC and age. Analysis of the attitudes to doctors confirmed previous findings that involving the patient in the management of their infection can improve overall compliance. The study identified seven key attitudes to antibiotic use with the potential to improve compliance. However, there was a poor understanding in 10 of the 11 countries of how non-compliance can increase the potential for resistance development. Segmentation and cluster analysis identified four psychographic profiles influencing compliant behaviour, which varied across countries. The global picture of antibiotic non-compliance and psychographic profiling should help identify areas for targeted, country-specific patient educational programmes as well as those areas where physicians can improve their interaction with their patients.

The use of macrolides in treatment of upper respiratory tract infections

Antimicrobial resistance is a growing problem among upper respiratory tract pathogens. Resistance to beta-lactam drugs among Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes is increasing. As safe and well-tolerated antibiotics, macrolides play a key role in the treatment of community-acquired upper respiratory tract infections (RTIs). Their broad spectrum of activity against gram-positive cocci, such as S. pneumoniae and S. pyogenes, atypical pathogens, H. influenzae (azithromycin and clarithromycin), and Moraxella catarrhalis, has led to the widespread use of macrolides for empiric treatment of upper RTIs and as alternatives for patients allergic to beta-lactams. Macrolide resistance is increasing among pneumococci and recently among S. pyogenes, and is associated with increasing use of the newer macrolides, such as azithromycin. Ribosomal target modification mediated by erm(A) and erm(B) genes and active efflux due to mef(A) and mef(E) are the principal mechanisms of resistance in both S. pneumoniae and S. pyogenes. Recently, ribosomal protein and RNA mutations have been found to be responsible for acquired resistance to macrolides in S. pneumoniae, S. pyogenes, and H. influenzae. Although macrolides are only weakly active against macrolide-resistant streptococci species, producing an efflux pump (mef), and are inactive against pathogens with ribosomal target modification (erm), treatment failures are uncommon. Therefore, macrolide therapy, for now, remains a good alternative for treatment of upper RTIs; however, continuous monitoring of the local resistance patterns is essential.

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.

The use of macrolides in treatment of upper respiratory tract infections

Antimicrobial resistance is a growing problem among upper respiratory tract pathogens. Resistance to beta-lactam drugs among Streptococcus pneumoniae, Haemophilus influenzae, and Streptococcus pyogenes is increasing. As safe and well-tolerated antibiotics, macrolides play a key role in the treatment of community-acquired upper respiratory tract infections (RTIs). Their broad spectrum of activity against gram-positive cocci, such as S. pneumoniae and S. pyogenes, atypical pathogens, H. influenzae (azithromycin and clarithromycin), and Moraxella catarrhalis, has led to the widespread use of macrolides for empiric treatment of upper RTIs and as alternatives for patients allergic to b-lactams. Macrolide resistance is increasing among pneumococci and recently among S. pyogenes, and is associated with increasing use of the newer macrolides, such as azithromycin. Ribosomal target modification mediated by erm(A) and erm(B) genes and active efflux due to mef(A) and mef(E) are the principal mechanisms of resistance in S. pneumoniae and S. pyogenes. Recently, ribosomal protein and RNA mutations have been found responsible for acquired resistance to macrolides in S. pneumoniae, S. pyogenes, and H. influenzae. Although macrolides are only weakly active against macrolide-resistant streptococci species producing an efflux pump (mef) and are inactive against pathogens with ribosomal target modification (erm), treatment failures are uncommon. Therefore, macrolide therapy, for now, remains a good alternative for treatment of upper RTIs; however, continuous monitoring of the local resistance patterns is essential.

Clarithromycin in 2003: sustained efficacy and safety in an era of rising antibiotic resistance

Data from surveillance studies show increasing prevalence of respiratory pathogens resistant to commonly used antibiotics. Thus, a Medline search was conducted to identify studies of clarithromycin, especially those addressing macrolide resistance. Changing trends of in vitro susceptibility have not affected clinical efficacy with clarithromycin. Over the last 12 years, clarithromycin study results have shown consistent rates of clinical cure and bacteriological eradication, which are similar to those observed with comparator agents. The incidence of clarithromycin treatment failure in patients infected with Streptococcus pneumoniae is substantially less than that predicted by macrolide resistance rates from surveillance programmes. In summary, despite widespread use since its introduction, clarithromycin remains active both in vitro and in vivo against clinically relevant respiratory tract pathogens.

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.

Review of macrolides and ketolides: focus on respiratory tract infections

The first macrolide, erythromycin A, demonstrated broad-spectrum antimicrobial activity and was used primarily for respiratory and skin and soft tissue infections. Newer 14-, 15- and 16-membered ring macrolides such as clarithromycin and the azalide, azithromycin, have been developed to address the limitations of erythromycin. The main structural component of the macrolides is a large lactone ring that varies in size from 12 to 16 atoms. A new group of 14-membered macrolides known as the ketolides have recently been developed which have a 3-keto in place of the L-cladinose moiety. Macrolides reversibly bind to the 23S rRNA and thus, inhibit protein synthesis by blocking elongation. The ketolides have also been reported to bind to 23S rRNA and their mechanism of action is similar to that of macrolides. Macrolide resistance mechanisms include target site alteration, alteration in antibiotic transport and modification of the antibiotic. The macrolides and ketolides exhibit good activity against gram-positive aerobes and some gram-negative aerobes. Ketolides have excellent activity versus macrolide-resistant Streptococcus spp. Including mefA and ermB producing Streptococcus pneumoniae. The newer macrolides, such as azithromycin and clarithromycin, and the ketolides exhibit greater activity against Haemophilus influenzae than erythromycin. The bioavailability of macrolides ranges from 25 to 85%, with corresponding serum concentrations ranging from 0.4 to 12 mg/L and area under the concentration-time curves from 3 to 115 mg/L x h. Half-lives range from short for erythromycin to medium for clarithromycin, roxithromycin and ketolides, to very long for dirithromycin and azithromycin. All of these agents display large volumes of distribution with excellent uptake into respiratory tissues and fluids relative to serum. The majority of the agents are hepatically metabolised and excretion in the urine is limited, with the exception of clarithromycin. Clinical trials involving the macrolides are available for various respiratory infections. In general, macrolides are the preferred treatment for community-acquired pneumonia and alternative treatment for other respiratory infections. These agents are frequently used in patients with penicillin allergies. The macrolides are well-tolerated agents. Macrolides are divided into 3 groups for likely occurrence of drug-drug interactions: group 1 (e.g. erythromycin) are frequently involved, group 2 (e.g. clarithromycin, roxithromycin) are less commonly involved, whereas drug interactions have not been described for group 3 (e.g. azithromycin, dirithromycin). Few pharmacoeconomic studies involving macrolides are presently available. The ketolides are being developed in an attempt to address the increasingly prevalent problems of macrolide-resistant and multiresistant organisms.

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.