From the Guidelines
Metrogyl (metronidazole) can be given for the treatment of non-severe Clostridioides difficile infection (CDI) in adults, but only when fidaxomicin or vancomycin are not available. The recommended dose is 500 mg orally three times daily for 10-14 days 1. According to the 2021 clinical practice guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA), metronidazole is an alternative treatment for non-severe CDI, but it is not the preferred treatment due to the risk of cumulative and potentially irreversible neurotoxicity 1.
Key Considerations
- Metronidazole should only be used for the treatment of initial episode of non-severe CDI, as defined by a white blood cell count of ≤15,000 cells/μL and a serum creatinine level <1.5 mg/dL 1.
- The use of metronidazole for the treatment of CDI is limited due to the risk of treatment failures, especially in patients infected with the emergent 027/BI/NAP1 strain 1.
- Vancomycin is the preferred treatment for severe CDI, and fidaxomicin is a valid alternative for the treatment of CDI in patients who are at higher risk for recurrence 1.
Important Safety Information
- Patients should be advised to take the full course of metronidazole even if symptoms improve early, and to avoid alcohol during treatment and for 48 hours afterward to prevent disulfiram-like reactions 1.
- Common side effects of metronidazole include metallic taste, nausea, and darkened urine, and patients with liver disease may require dose adjustments 1.
Clinical Judgment
The decision to use metronidazole for the treatment of CDI should be made on a case-by-case basis, taking into account the severity of the disease, the patient's medical history, and the availability of alternative treatments. Clinicians should carefully weigh the benefits and risks of metronidazole treatment and consider alternative treatments, such as vancomycin or fidaxomicin, when possible 1.
From the FDA Drug Label
Prescribing metronidazole tablets in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of development of drug-resistant bacteria. Patients should be counseled that antibacterial drugs including metronidazole tablets should only be used to treat bacterial infections.
Metrogyl (metronidazole) can be given to treat bacterial infections, but only when there is a proven or strongly suspected bacterial infection or a prophylactic indication. It should not be used to treat viral infections. 2
From the Research
Metrogyl (Metronidazole) Administration
- Metrogyl, also known as metronidazole, is a treatment of choice for several types of infections, including trichomoniasis, amoebiasis, giardiasis, and anaerobic bacterial infections 3, 4, 5.
- It can be administered orally or intravenously, with an oral bioavailability approaching 100% 6.
- The drug has limited plasma protein binding but can attain favorable tissue distribution, including into the central nervous system 6.
Contraindications and Precautions
- Coexisting conditions or concomitant medications may preclude the use of metronidazole 3.
- Absolute contraindications to the nitroimidazole antibiotics, including metronidazole, exist, and alternative therapies are available 3.
- Metronidazole has been associated with toxicity, including neurotoxicity, optic neuropathy, peripheral neuropathy, and encephalopathy, although these side effects are rare 4.
Dosage and Efficacy
- The efficacy of once-daily versus multiple dose regimens of metronidazole has been compared in patients with serious systemic infections, with results suggesting that once-daily metronidazole is as efficacious as multiple-dosed metronidazole regimens 7.
- Metronidazole has been shown to be efficacious in the therapy of a variety of anaerobic infections, including non-traumatic brain abscesses, intraabdominal sepsis, pelvic suppuration, and necrotizing soft tissue infections 5.
- The drug is usually bactericidal at low concentrations, and its spectrum of activity encompasses almost all anaerobic bacteria and some capnophilic organisms 5.