Azithromycin (Zithromax) versus ...
Azithromycin (Zithromax) vs. Clarithromycin (Biaxin)
Azithromycin (3-day, once-daily course) is as effective and well tolerated as clarithromycin (10-day, twice-daily course) in the treatment of mild to moderate community-acquired pneumonia.
Randomized, multicentre study7 compared azithromycin versus clarithromycin in the treatment of adults with mild to moderate community-acquired pneumonia. A satisfactory clinical response was recorded at the end of therapy in 83 of 88 (94%) evaluable azithromycin-treated and 84 of 88 (95%) evaluable clarithromycin-treated patients. At day 19-23, only one patient in each group had relapsed. Thirty-one of 32 (97%) pathogens isolated from patients in the azithromycin group were eradicated, compared with 32 of 35 (91%) isolated from clarithromycin patients. Incidences of adverse events were similar for the two groups. Two (2%) clarithromycin patients discontinued therapy due to severe adverse events; none in the azithromycin group did.
Acute exacerbation of chronic bronchitis
Three-day treatment with azithromycin 500 mg once daily is equivalent to a 10-day treatment with clarithromycin 500 mg twice daily in adults with acute exacerbation of chronic bronchitis (AECB).
Randomized, double-blind, multicenter study6 compared the efficacy and safety of azithromycin 500 mg once daily for 3 days with those of clarithromycin 500 mg twice daily for 10 days. The clinical cure (based on direct observation of the patient) rates were equivalent in the two groups at 85% with azithromycin and 82% with clarithromycin. Bacteriologic success rates were also equivalent between the groups at test of cure for S. pneumoniae (90.6% and 85.2%, respectively), H. influenzae (71.4% and 81.3%, respectively) and M. catarrhalis (100% and 86.7%, respectively). The overall incidence of adverse events was similar in the azithromycin and clarithromycin groups (20.9% and 26.8%, respectively), with the most common being abdominal cramps (6.3% and 6.1%, respectively), diarrhea (4.4% and 5.5%, respectively), and nausea (4.4% and 3.7%, respectively).
Both azithromycin and clarithromycin are effective for the treatment of children with acute otitis media (infection of the middle ear).
A randomized, open clinical trial8 compared the efficacy, safety and tolerance of azithromycin and clarithromycin in children with acute otitis media. Of 100 patients enrolled, 97 were considered evaluable. The most common middle ear pathogens were Streptococcus pneumoniae (60%), Haemophilus influenzae (15%) and Staphylococcus aureus (13%). Fifty patients (100%) treated with azithromycin and 45 (95.7%) patients treated with clarithromycin had a satisfactory clinical response. Rates of persistence of middle ear effusion and possible side effects were comparable.
Azithromycin (Zithromax) vs. Doxycycline
In clinical trials2, the bacteriological cure rate of a single dose of azithromycin 1000 mg (95 to 100%) was similar to that of doxycycline 200 mg/day for 7 days (88 to 100%).
However, according to the recent research1 azithromycin may be particularly effective against persistent chlamydia. In contrast, doxycycline may not be as effective in treating persistent infection.
Chronic chlamydial infections (e.g. pelvic inflammatory disease, trachoma) are a mixture of acute and persistent infections. Therefore azithromycin would be more effective for the treatment of chlamydial infections than doxycycline1.
Both azithromycin and doxycycline are effective in the treatment of non-gonococcal endocervicitis.
Prospective-randomised study3 compared azithromycin versus doxycycline in the treatment of non-gonococcal mucopurulent endocervicitis. The eradication rate of bacteria in the azithromycin group was 71.4%, and 77.3% in the doxycycline group.
Azithromycin 500 mg once a day for four days per month appears to be as effective as daily doxycycline 100 mg4.
Lyme disease (Erythema migrans)
Azithromycin is equally effective as doxycycline in the treatment
of Lyme disease.
Azithromycin (Zithromax) vs. Minocycline
Azithromycin is at least as effective as minocycline in the treatment of facial comedonic and papulopustular acne.
An open study10 compared the clinical efficacy and tolerability of azithromycin and minocycline. Azithromycin was administered as a single dose (500 mg/day) for 4 days in four cycles every 10 days and minocycline was administered 100 mg daily for 6 weeks. Improvement was assessed 6 weeks after initiation of treatment with a four-graded scale. A satisfactory clinical response was observed in 75.8% of the patients treated with azithromycin and in 70.5% of those treated with minocycline. Both agents were well tolerated and mild side effects were reported in 10.3% of azithromycin and 11.7% of minocycline treated patients.
Azithromycin (Zithromax) vs. Amoxicillin
Both amoxicillin and azithromycin are effective in the treatment of cervical Chlamydia trachomatis infection during pregnancy. However, azithromycin seems to have a lower rate of recurrent infection12. Amoxicillin is slightly better tolerated.
In a randomized controlled comparative trial11 there was similar efficacy between amoxicillin and azithromycin (58% vs 64%, respectively). In the study 5.5% of women were intolerant to amoxicillin, compared with 10.9% to azithromycin.
Single dose azithromycin is as effective as high dose amoxicillin for 10 days for the treatment of children with otitis media. Diarrhea occurs more frequently with amoxicillin.
In a randomized, multicenter, double blind trial13 children (6-30 months of age) with acute otitis media (AOM) were randomized to treatment with single dose azithromycin (30 mg/kg) or high dose amoxicillin (90 mg/kg/d, in 2 divided doses) for 10 days. The clinical success rates for azithromycin and amoxicillin were comparable for all patients (84% and 84%, respectively) and for children < or =2 years of age (82% and 82%, respectively). The clinical efficacies among all microbiologic modified intent-to-treat evaluable subjects were comparable for patients treated with azithromycin (80%) and patients treated with amoxicillin (83%). The rates of side effects for azithromycin and amoxicillin were 20% and 29%, respectively. Diarrhea was more common with amoxicillin (17.5%) than with azithromycin (8.2%). Compliance was higher in the azithromycin group (100%) than in the amoxicillin group (90%).
Amoxicillin is better than azithromycin for erythema migrans.
In a double-blind, randomized, controlled trial14 patients treated with amoxicillin were significantly more likely than those treated with azithromycin to achieve complete resolution of disease at day 20, the end of therapy (88% compared with 76%). More azithromycin-treated patients (16%) than amoxicillin-treated patients (4%) had relapse. For patients treated with azithromycin, development of an antibody response increased the possibility of achieving a complete response (81% of seropositive patients achieved a complete response compared with 60% of seronegative patients). Patients with multiple erythema migrans lesions were more likely than those with single erythema migrans lesions to have a positive antibody titer at baseline. Fifty-seven percent of patients who had relapse were seronegative at the time of relapse.
Azithromycin (Zithromax) vs. Co-Amoxiclav
Generally, azithromycin is significantly better tolerated and has shorter duration of therapy than amoxicillin/clavulanate.
Azithromycin and amoxicillin/clavulanate have similar efficacy in the treatment of acute otitis media in children.
Randomized, double-blind study15 compared azithromycin and amoxicillin/ clavulanate for the treatment of acute otitis media in children. One hundred and eighty-eight children (mean age 3.5 years) were randomized to azithromycin and 185 to co-amoxiclav. At day 10, the clinical success rate was 153/185 (83%) in children treated with azithromycin and 159/181 (88%) in children treated with co-amoxiclav. At day 28, 134/182 (74%) of the children were cured on azithromycin compared with 124/180 (69%) on co-amoxiclav. Also at day 28, signs of acute otitis media, such as abnormal reflectometry (45% versus 59%), bulging of the eardrum (10% versus 16%) and loss of tympanic membrane landmarks (11% versus 22%) were seen less frequently in azithromycin- than co-amoxiclav-treated children, respectively. Side effects were seen in 11% of azithromycin patients compared with 20% on co-amoxiclav.
Azithromycin and amoxicillin/clavulanate have similar efficacy in the treatment of sinusitis.
Randomized double-blind study16 compared 3- and 6-day regimens of azithromycin with a 10-day amoxicillin-clavulanate regimen for acute bacterial sinusitis. Clinical success rates were equivalent among patients at the end of therapy (azithromycin 3 days, 88.8%; azithromycin 6 days, 89.3%; amoxicillin/clavulanate, 84.9%) and at the end of the study (azithromycin 3 days, 71.7%; azithromycin 6 days, 73.4%; amoxicillin/clavulanate, 71.3%). Patients treated with amoxicillin/clavulanate reported a higher incidence of side effects (51.1%) than azithromycin-3 (31.1%) or 6-day (37.6%). More amoxicillin/clavulanate patients discontinued the study (n = 28) than azithromycin-3 (n = 7) and 6 (n = 11). Diarrhea was the most frequent side effect.
Lower respiratory tract infections
Azithromycin and amoxicillin/clavulanate have similar efficacy in the treatment of lower respiratory tract infections.
Multicentre randomized double-blind, double-dummy study17 compared the efficacy, safety and tolerability of a 3 day course of azithromycin with a 10 day course of co-amoxiclav in the treatment of children with acute lower respiratory tract infection. The percentage of patients cured or clinically improved at days 10-13 (primary endpoint) was 91% for azithromycin and 87% for co-amoxiclav. This difference of 4% was not statistically significant. Significantly more side effects were found in the co-amoxiclav group. This was largely due to a higher percentage (43% versus 19%) of gastrointestinal complaints.
Azithromycin (Zithromax) vs. Penicillin
Azithromycin (10 or 20 mg/kg/day one daily for 3 days) is as safe and effective as penicillin V (4 times daily for 10 days) in the treatment of children with acute pharyngitis/tonsillitis.
The efficacy and safety of azithromycin and penicillin V in the treatment of acute streptococcal pharyngitis/tonsillitis in paediatric patients were compared in a double-blind, double-dummy prospective study9. A satisfactory clinical response (cure or improvement) was recorded in 99% of the 10 mg/kg azithromycin group, 100% of the 20 mg/kg azithromycin group, and 97% of the penicillin V group at the end of therapy (day 12-14). At the follow-up evaluation (day 28-30), relapse rates in patients cured or improved at the end of therapy were 6%, 5%, and 2%, respectively. Bacteriological eradication rates at the end of therapy were 98% in both azithromycin groups and 92% in penicillin V group; pathogen recurrence was recorded at follow-up in 4% of the 20 mg/kg azithromycin group and in 6% of both the 10 mg/kg azithromycin and penicillin V groups. Adverse events, the majority of mild to moderate severity, occurred in 13% of patients in the 20 mg/kg azithromycin group, 9% in the 10 mg/kg group, and 5% in the penicillin V group.
Azithromycin appears to be as effective as penicillin V for the treatment of early Lyme disease and it may clear the erythema migrans more promptly.
In a randomized multicenter therapeutic trial20 32 patients with erythema migrans received oral azithromycin 500 mg once daily and 33 patients received phenoxymethylpenicillin (penicillin V) 1 million U three times daily for 10 days. Four weeks after initiation of therapy, 20 (62%) patients given azithromycin and 17 (51%) patients given penicillin V were completely free of all signs and symptoms and did not develop new ones subsequently (no significant difference). Three months after initiation of therapy, the corresponding figures were 25 (78%) azithromycin and 28 (85%) penicillin V recipients (no significant difference). There were only minor sequelae such as arthralgia, headache, fatigue, stiff neck and dysesthesia. Azithromycin led to a significantly faster resolution of the erythema migrans than penicillin V. Usually mild to moderate side effects occurred in 12 patients given azithromycin and five patients given penicillin V.
Azithromycin (Zithromax) vs. Cefadroxil (Duricef)
Azithromycin may be somewhat more effective and better tolerated than cefadroxil for treating uncomplicated skin and skin structure infections.
Multicenter, investigator-blind study18 compared the efficacy and safety of azithromycin and cefadroxil for the treatment of uncomplicated skin and skin structure infections. Clinical and bacteriologic response was assessed between days 10 and 13 (primary end point) and between days 28 and 32. Clinical success (resolution of symptoms) rates assessed between days 10 and 13 were 97% (111/114) for azithromycin and 96% (101/105) for cefadroxil. For azithromycin and cefadroxil, corresponding rates of bacteriologic eradication for Staphylococcus aureus were 94% (64/68) and 86% (60/70), respectively, and for Streptococcus pyogenes, 80% (4/5) and 100% (6/6), respectively. Clinical success rates assessed between days 28 and 32 were 100% (82/82) for azithromycin compared with 90% (75/83) for cefadroxil. Corresponding rates of eradication for S. aureus were 100% (59/59) versus 89% (56/63), respectively; and for S. pyogenes, 100% (4/4) versus 83% (5/6), respectively. The incidence of side effects was similar in the groups. However, 5 of the 139 patients (4%) in the cefadroxil group discontinued therapy because of side effect compared with none of the 152 patients in the azithromycin group.
Azithromycin (Zithromax) vs. Cefdinir (Omnicef)
Pneumococcal pulmonary infections
Cefdinir or azithromycin have comparable effectiveness in the treatment of acute otitis media.
A multicenter, prospective, single-blind study19 compared cefdinir and azithromycin in children with acute otitis media. Three hundred fifty-seven patients were enrolled in the study. The majority of evaluable children (77%) had previously received conjugated heptavalent pneumococcal vaccine (PCV7) against Streptococcus pneumonia. At the end-of-therapy visit, clinical cure (resolution of symptoms) rates were comparable for cefdinir and azithromycin (87%, [151/174] and 85% [149/176], respectively). In addition, clinical cure rates at the end-of-therapy visit in the children who had been vaccinated with PCV7 were comparable between cefdinir and azithromycin (86% vs 83%). No significant difference in clinical cure rates was observed at the follow-up visit (76% and 86%). Parental satisfaction was similar between groups with regard to ease of use, taste, compliance, health care resource utilization, and missed days of work and day-care. Diarrhea and abnormal stools were the most common side effects.
Published: March 31, 2008