Comparing the Antimicrobial In Vitro Efficacy of Amoxicillin/Metronidazole against Azithromycin—A Systematic Review

Abstract

On account of its proven clinical efficacy, the combination of systemically administered amoxicillin and metronidazole is frequently adjuncted to non-operative periodontal therapy and well documented. Potential drawbacks of this regimen, e.g., side effects and problems with the compliance, led to an ongoing search for alternatives. Azithromycin, an antibiotic extensively used in general medicine, has recently found its niche in periodontal therapy as well. This systematic review aimed to analyze the in vitro antimicrobial efficacy of amoxicillin plus metronidazole versus azithromycin. For this purpose, a systematic literature search was performed, and studies published up to 29 March 2018 referenced in Medline, Embase, Cochrane, and Biosis were independently screened by two authors. An additional hand search was performed and studies focusing on the evaluation of in vitro antimicrobial efficacy of amoxicillin + metronidazole or azithromycin on bacteria from the subgingival biofilm were included. English and German language research reports were considered. From 71 identified articles, only three articles were eligible for inclusion. These studies showed heterogeneity in terms of analytical methods and strains explored. However, all studies used multispecies biofilm models for analysis of the antimicrobial activity. Unanimously, studies reported on more pronounced antimicrobial effects when applying the combination of amoxicillin + metronidazole, compared to azithromycin. Based on the few studies available, the combination of amoxicillin + metronidazole seemed to display higher antimicrobial efficacy in vitro than azithromycin.

Comparison of Clinical Attachment Level Gain Using Scaling Root Planing Versus Adjunctive Azithromycin on Chronic Periodontitis

“…12 Among the systemic antibiotics, Azithromycin has shown better patient compliance. 20 This was confirmed in present study as no adverse effects were noted, apart from mild diarrhea in 3 of the 30 patients (10%) from the study group. The approved dosages of Azithromycin are (5-day regime, 1 st dose of 500mg and then 250mg everyday) and (3-day regime of 500mg everyday).…”

“…13 The recommended regime is 3-4 doses per day for 7-14 days and they have been associated with bacterial resistance and several side effects which reduces their compliance. 14 Azithromycin a macrolide antibiotic, has less resistance, fewer adverse effects, and is administered once daily which promotes patient compliance. 15 It accumulates effectively in phagocytes and has good periodontal tissue penetration thus being delivered in high concentrations to sites of infection where it remains detectable for 14 days.…”

Periodontal microbiology and microbial etiology of periodontal diseases: Historical concepts and contemporary perspectives

“…100 To draw clear conclusions, however, comparable data on their efficacy are very limited so far. 223,224 A clinically relevant question is what kind of patient could get benefit of adjunctively used systemic antimicrobials. In a Swiss randomized clinical trial where patients received non-surgical periodontal treatment and the combination of metronidazole and amoxicillin (test group) or placebo (controls), an improved clinical outcome was shown in the test group irrespective of their baseline detection of A. actinomycetemcomitans, sex, age, or smoking status.…”

Systemic azithromycin versus amoxicillin/metronidazole as an adjunct in the treatment of periodontitis: a systematic review and meta‐analysis

“…Two reviews 36,61 have directly compared the adjunctive use of AZT to AMX/MTZ in the non-surgical treatment of periodontitis. The first review of Kaufmann and co-workers 61 was a systematic review of in-vitro studies which demonstrated that AMX/MTZ had more pronounced antimicrobial efficacy than AZT but the conclusions were only based on three studies with significant methodological heterogeneity. The second review 36 was a systematic review of clinical trials and concluded that the efficacy of both antibiotic regimens in reducing probing pocket depths is comparable.…”

“…32 Several clinical trials [23][24][25]30,[33][34][35] have demonstrated the additional clinical and microbiological benefits of systemic AZT and AMX/MTZ over SI alone, but did not compare the two antibiotic regimens. A systematic review 36 concluded that the efficacy of both antibiotic regimens in reducing probing pocket depths was comparable but the results were only based on two RCTs. Hence, the findings regarding the potential superiority of one antibiotic regimen over the other remain inconclusive and further evidence is still required.…”