Goolsby TA, et al. - In this work, researchers reviewed and evaluated the literature on metronidazole-associated peripheral neuropathy and determined the relevance in clinical practice. Findings revealed a higher risk of peripheral neuropathy among patients who received larger total doses but most patients had resolution of symptoms after discontinuing therapy. They realized that antimicrobial stewardship programs could consider use of antibiotic combinations that include metronidazole over broad-spectrum alternatives when treating with ≤42 grams of the drug (≤4 weeks).

Methods

• Researchers searched MEDLINE/PubMed, EBSCO, and Google Scholar through February 2017 using the search terms metronidazole and peripheral neuropathy, or polyneuropathy, or paresthesia, or neurotoxicity.
• They included relevant case reports, retrospective studies, surveys, and review articles.
• They, in addition, reviewed the bibliographies of all relevant articles for additional sources.

Results

• Overall, metronidazole was generally well tolerated but serious neurotoxicity, including peripheral neuropathy, had been reported.
• The overall incidence rate of metronidazole associated peripheral neuropathy remained unrecognized.
• They identified 36 case reports (40 unique patients) of metronidazole-associated peripheral neuropathy with the majority of cases receiving >42 total grams (>4 weeks) of therapy (31 out of 40).
• In addition, 13 clinical studies indicated varying rates of peripheral neuropathy from 0-50%.
• Within these clinical studies, there appeared a higher incidence of peripheral neuropathy in patients receiving >42 total grams (>4 weeks) of metronidazole compared to those patients receiving ≤ 42 total grams (17.9% vs 1.7%).
• Complete resolution of symptoms was observed in nearly all patients.
• Peripheral neuropathy seemed exceedingly rare in patients who receive ≤ 42 total grams of metronidazole.