Adverse events of metronidazole and amoxicillin: Retrospective analysis of a large data set of five randomized clinical trials

J Clin Periodontol. 2022 Nov;49(11):1121-1132. doi: 10.1111/jcpe.13704. Epub 2022 Aug 5.

Abstract

Aim: To evaluate the frequency of side effects associated with intake of metronidazole (MTZ) + amoxicillin (AMX) in periodontal treatment, and to explore associations between these events and patients' features.

Materials and methods: Data of five randomized clinical trials testing MTZ + AMX adjunctive to mechanical therapy were evaluated. Volunteers answered an adverse event questionnaire.

Results: Information from 656 subjects was assessed. The frequency of side effects in the antibiotic- and placebo-treated groups ranged from 1.0% to 17.7% and 0.9% to 13.7%, respectively. The events more frequently observed in the antibiotic than in the placebo group were diarrhoea and metallic taste (p < .05). Diabetes significantly raised the odds of a patient reporting discomfort (odds ratio [OR] = 2.6), diarrhoea (OR = 4.0), weakness (OR = 6.0) and excessive sleepiness (OR = 2.9). In systemically healthy volunteers, using antibiotics 3 months post-mechanical treatment (healing phase) (OR = 3.0), being a woman (OR = 3.9) and aged ≤49 (OR = 4.5) significantly increased the chances of reporting adverse events.

Conclusions: The occurrence of side effects during MTZ + AMX treatment ranged from uncommon (1%) to very common (17.7%). The main factors raising the chances of a patient reporting adverse events were diabetes and taking antibiotics in the healing phase, instead of in the active phase of treatment. Patients ≤ 49 years old and females also tend to report more side effects.

Keywords: adverse events; amoxicillin; metronidazole; periodontal treatment; periodontitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amoxicillin* / adverse effects
  • Anti-Bacterial Agents / adverse effects
  • Chronic Periodontitis* / therapy
  • Dental Scaling
  • Diarrhea / chemically induced
  • Diarrhea / drug therapy
  • Double-Blind Method
  • Female
  • Humans
  • Metronidazole / adverse effects
  • Middle Aged
  • Randomized Controlled Trials as Topic
  • Retrospective Studies

Substances

  • Anti-Bacterial Agents
  • Metronidazole
  • Amoxicillin