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Metronidazole

    Brands

    DEA Class; Rx

    Common Brand Names; Flagyl, Flagyl ER, Flagyl IV RTU

    • Nitroimidazoles

    metronidazole topical (Rx)

    Brand and Other Names: MetroCream, MetroGel, MetroLotion, Noritate
    • Classes: Antibacterials, Topical

    metronidazole vaginal (Rx)

    Brand and Other Names: MetroGel Vaginal, Vandazole, Nuvessa
    • Classes: Antibiotics, Other; 
    • Vaginal Preparations, Other

    Oral/parenteral/topical/vaginal synthetic nitroimidazole; antibacterial and antiprotozoal
    Used for anaerobic bacterial infections and protozoal infections such as trichomoniasis, amebiasis, and giardiasis
    Associated with neurotoxicity

    Indicated for the treatment of trichomoniasis.

    For the treatment of bacterial vaginosis.
    For the treatment of gynecologic infections, including endometritis, endomyometritis, post-surgical cuff infection, pelvic inflammatory disease (PID), and tubo-ovarian abscess.
    For the treatment of acute intestinal amebiasis (amebic dysentery) and disseminated amebiasis, including hepatic abscess.
    For the treatment of central nervous system infections, including meningitis and brain abscess.
    For the treatment of acne rosacea.
    For the treatment of lower respiratory tract infections, including pleural empyema, pneumonia, and lung abscess.
    For the treatment of skin and skin structure infections, including cellulitis, erysipelas, necrotizing infections, animal bite wounds, leg ulcer, diabetic foot ulcer, and surgical incision site infections.
    For the treatment of endocarditis.
    For the treatment of bone and joint infections.
    For bacterial vaginosis prophylaxis or trichomoniasis prophylaxis in victims of sexual assault.
    For the treatment of recurrent and persistent non-gonococcal urethritis (NGU).
    For the treatment of dental infection or dentoalveolar infection, including periodontitis.
    For surgical infection prophylaxis, including bowel preparation in patients undergoing colorectal surgery.
    For the treatment of pseudomembranous colitis due to C. difficile infection.
    For the treatment of Crohn’s disease associated with colonic and/or perianal involvement.
    For Helicobacter pylori (H. pylori) eradication.

    Hypersensitivity to metronidazole or other nitroimidazoles (although cautious desensitization has been applied)

    Pregnancy, 1st trimester in patients with trichomoniasis

    Use of disulfiram within past 2 weeks; use of alcohol during therapy or within 3 days of discontinuing therapy

    Consumption of alcohol or products containing propylene glycol within least three days of receiving metronidazole

    Patients with Cockayne syndrome

    • Appetite loss
    • Candidiasis
    • Diarrhea
    • Dizziness
    • Headache
    • Nausea
    • Vomiting
    • Ataxia
    • Dark urine
    • Disulfiram-type reaction with ethanol
    • Furry tongue
    • Hypersensitivity
    • Neutropenia
    • Metallic taste
    • Neuropathy
    • Pancreatitis
    • Seizures
    • Thrombophlebitis
    • Xerostomia
    • Encephalopathy
    • Aseptic meningitis
    • Optic neuropathy
    • Stevens-Johnson syndrome
    • Toxic epidermal necrolysis
    • Decreased libido

    Severe irreversible hepatotoxicity/acute liver failure with fatal outcomes reported after initiation of metronidazole, another nitroimidazole drug, structurally related to benznidazole in patients with Cockayne syndrome

    Seizures and aseptic meningitis reported with increase in dose and chronic therapy

    Cases of encephalopathy and peripheral neuropathy (including optic neuropathy) reported with metronidazole

    Encephalopathy reported in association with cerebellar toxicity characterized by ataxia, dizziness, and dysarthria; CNS lesions seen on MRI described in reports of encephalopathy; CNS symptoms are generally reversible within days to weeks upon discontinuation of therapy; lesions seen on MRI have also been described as reversible

    Peripheral neuropathy, mainly of sensory type reported and characterized by numbness or paresthesia of an extremity

    Prescribing metronidazole tablets in absence of a proven or strongly suspected bacterial or parasitic infection or a prophylactic indication is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria and parasites

    Superinfection may occur with prolonged use

    Severe hepatic impairment; administer lower doses with caution

    Use with caution; potential accumulation in end stage renal disease; supplemental doses may be needed in patients receiving hemodialysis

    Use with caution in history of heart failure, hepatic failure, H. pylori infection, renal impairment

    Use with care in patients with evidence of or history of blood dyscrasia; agranulocytosis, leukopenia and neutropenia have been associated with metronidazole administration; monitor complete blood count; monitor complete blood count (CBC) for leukopenia before, during, and after prolonged repeated therapy

    Avoid alcohol while taking medication and for at least three days after discontinuation

    Antiandrogen: May cause gynecomastia

    Known or previously unrecognized candidiasis may present more prominent symptoms during therapy and requires treatment with a candicidal agent

    There are no adequate and well-controlled studies of in pregnant women; there are published data from case-control studies, cohort studies, and 2 meta-analyses that include more than 5000 pregnant women who used metronidazole during pregnancy

    Metronidazole is present in human milk at concentrations similar to maternal serum levels, and infant serum levels can be close to or comparable to infant therapeutic levels

    Adults

    2,250 mg/day IV/PO is usual maximum; however, up to 4 g/day IV/PO in FDA-approved labeling.

    Geriatric

    2,250 mg/day IV/PO is usual maximum; however, up to 4 g/day IV/PO in FDA-approved labeling.

    Adolescents

    50 mg/kg/day (Max: 2,250 mg/day) PO; safety and efficacy of IV use have not been established; however, doses up to 40 mg/kg/day (Max: 2,250 mg/day) IV have been used off-label.

    Children

    50 mg/kg/day (Max: 2,250 mg/day) PO; safety and efficacy of IV use have not been established; however, doses up to 40 mg/kg/day (Max: 2,250 mg/day) IV have been used off-label.

    Infants

    50 mg/kg/day PO; safety and efficacy of IV have not been established; however, doses up to 40 mg/kg/day IV have been used off-label.

    Neonates

    Postmenstrual age (PMA) older than 40 weeks: Safety and efficacy have not been established; however, doses up to 30 mg/kg/day IV have been used off-label.
    PMA 35 to 40 weeks: Safety and efficacy have not been established; however, doses up to 22.5 mg/kg/day IV have been used off-label.
    PMA 34 weeks and younger: Safety and efficacy have not been established; however, doses up to 15 mg/kg/day IV have been used off-label.

    Metronidazole

    capsule

    • 375mg

    tablet

    • 250mg
    • 500mg

    tablet, extended-release

    • 750mg

    infusion solution

    • 500mg/100mL

    topical gel

    • 1% (MetroGel)

    topical cream

    • 0.75% (MetroCream)
    • 1% (Noritate)

    topical lotion

    • 0.75% (MetroLotion)

    vaginal gel

    • 0.75% (MetroGel Vaginal, Vandazole)
    • 1.3% (Nuvessa)