Patient Safety and Efficacy of Metronidazole 1 g Intravenous Every 24 Hours

BACKGROUND: Metronidazole (MTZ) is an imidazole that is used to treat parasites and anaerobic infections. The traditional dose of 500 mg every 6 to 8 hours achieves adequate serum concentration to treat most anaerobic infections. MTZ has a concentration dependent bactericidal activity with a long half-life of 8 hours and also exhibits post-antibiotic effect. The literature lacks clinical data in regards to a once daily higher dose of IV MTZ. METHODS: A retrospective quality improvement project via electronic medical record review of 88 adults who received MTZ 1 gm IV daily at a single tertiary medical center, from April 2014 to October 2016. Inclusion criteria were patients >/=18 years who received MTZ 1 gm IV every daily for >/= 48 hours. RESULTS: Of the 88 patients who received 1 gm of MTZ, 66 met inclusion criteria. Mean age was 58 years (range 24 to 90 years). Indications for use are shown in Figure 1. Mean duration of therapy was 10 days (range 2 to 42 days). Twenty-nine (43.9%) received </= 6 days and 37 (56.1%) received >/= 7 days. Fourteen (21%) were discharged home on MTZ 1 gm IV daily for 4–6 weeks duration. One patient had a documented adverse reaction (severe nausea) while the other 65 tolerated well. No documented treatment failure was reported. CONCLUSION: MTZ has been used in combination with other antimicrobial agents to treat polymicrobial infections. It is generally well tolerated when administered in dosages of <2gm per day. Pharmacodynamic studies have demonstrated activity for 12 to 24 hours after administration of 1 gm of MTZ. Our study showed no safety concerns with 1 gm daily dosing and no reported treatment failure. The limitation of our study includes lack of comparative cohort. The potential advantages of once daily dosing include optimized bacterial killing, minimization of drug administration, and reduction of the cost of antibiotics as well as the cost of administration. Our safety and quality improvement project support that MTZ 1 gm IV daily dose is potentially a safe, efficacious and cost effective alternative to three times dosing especially in hospitalized patients and may have role in OPAT. DISCLOSURES: All authors: No reported disclosures.