pharmacopeia
GET
/api/v1/drug/metronidazole

Boxed warning

Metronidazole has been shown to be carcinogenic in mice and rats (see PRECAUTIONS ). Unnecessary use of the drug should be avoided. Its use should be reserved for the conditions described in the INDICATIONS AND USAGE section below.

2D structure
2-(2-methyl-5-nitroimidazol-1-yl)ethanol
SMILES CC1=NC=C(N1CCO)[N+](=O)[O-]
InChIKey VAOCPAMSLUNLGC-UHFFFAOYSA-N

Mechanism of action

Sourced from openFDA

Mechanism-of-action class: Unknown Cellular or Molecular Interaction.

Indications

Sourced from openFDA
  • Symptomatic Trichomoniasis. Metronidazole tablets are indicated for the treatment of T.

Contraindications

Sourced from openFDA
  • Hypersensitivity Metronidazole tablet are contraindicated in patients with a prior history of hypersensitivity to metronidazole or other nitroimidazole derivatives. In patients with trichomoniasis, metronidazole tablet are contraindicated during the first trimester of pregnancy (see PRECAUTIONS ).contraindicated

Dosage & administration

Sourced from openFDA

Trichomoniasis: In the Female: One-day treatment − two grams of metronidazole tablets, given either as a single dose or in two divided doses of one gram each, given in the same day. Seven-day course of treatment − 250 mg three times daily for seven consecutive days. There is some indication from controlled comparative studies that cure rates as determined by vaginal smears and signs and symptoms, may be higher after a seven-day course of treatment than after a one-day treatment regimen. The dosage regimen should be individualized. Single-dose treatment can assure compliance, especially if administered under supervision, in those patients who cannot be relied on to continue the seven-day regimen. A seven-day course of treatment may minimize reinfection by protecting the patient long enough for the sexual contacts to obtain appropriate treatment. Further, some patients may tolerate one treatment regimen better than the other. Pregnant patients should not be treated during the first trimester (see CONTRAINDICATIONS ). In pregnant patients for whom alternative treatment has been inadequate, the one-day course of therapy should not be used, as it results in higher serum levels which can reach the fetal circulation (see PRECAUTIONS, Pregnancy ). When repeat courses of the drug are required, it is recommended that an interval of four to six weeks elapse between courses and that the presence of the trichomonad be reconfirmed by appropriate laboratory measures. Total and differential leukocyte counts should be made before and after re-treatment.

Warnings & precautions

Sourced from openFDA

Hypersensitivity Reactions Hypersensitivity reactions including severe cutaneous adverse reactions (SCARs) can be serious and potentially life threatening (see ADVERSE REACTIONS ). Severe Cutaneous Adverse Reactions Severe cutaneous adverse reactions (SCARs) including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP) have been reported with the use of metronidazole. Symptoms can be serious and potentially life threatening (If symptoms or signs of SCARs develop, discontinue metronidazole tablets immediately and institute appropriate therapy. Central and Peripheral Nervous System Effects Encephalopathy and peripheral neuropathy: Cases of encephalopathy and peripheral neuropathy (including optic neuropathy) have been reported with metronidazole. Encephalopathy has been reported in association with cerebellar toxicity characterized by ataxia, dizziness, and dysarthria. CNS lesions seen on MRI have been described in reports of encephalopathy. CNS symptoms are generally reversible within days to weeks upon discontinuation of metronidazole. CNS lesions seen on MRI have also been described as reversible. Peripheral neuropathy, mainly of sensory type has been reported and is characterized by numbness or paresthesia of an extremity. Convulsive seizures have been reported in patients treated with metronidazole. Aseptic meningitis: Cases of aseptic meningitis have been reported with metronidazole.

Adverse reactions

Sourced from openFDA

The following reactions have been reported during treatment with metronidazole: Central Nervous System: The most serious adverse reactions reported in patients treated with metronidazole have been convulsive seizures, encephalopathy, aseptic meningitis, optic and peripheral neuropathy, the latter characterized mainly by numbness or paresthesia of an extremity. Since persistent peripheral neuropathy has been reported in some patients receiving prolonged administration of metronidazole, patients should be specifically warned about these reactions and should be told to stop the drug and report immediately to their physicians if any neurologic symptoms occur. In addition, patients have reported headache, syncope, dizziness, vertigo, incoordination, ataxia, tinnitus, hearing impairment, hearing loss, confusion, dysarthria, irritability, depression, weakness, and insomnia (see WARNINGS ). Gastrointestinal: The most common adverse reactions reported have been referable to the gastrointestinal tract, particularly nausea, sometimes accompanied by headache, anorexia, and occasionally vomiting; diarrhea; epigastric distress; and abdominal cramping and constipation. Mouth : A sharp, unpleasant metallic taste is not unusual. Furry tongue, glossitis, and stomatitis have occurred; these may be associated with a sudden overgrowth of Candida which may occur during therapy. Dermatologic : Dermatitis bullous, fixed drug eruption, erythematous rash and pruritus. Hematopoietic : Reversible neutropenia (leukopenia); rarely, reversible thrombocytopenia.

Use in specific populations

Sourced from openFDA

Pregnancy: Teratogenic Effects There are no adequate and well controlled studies of metronidazole 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. Many studies included first trimester exposures. One study showed an increased risk of cleft lip, with or without cleft palate, in infants exposed to metronidazole in-utero; however, these findings were not confirmed. In addition, more than ten randomized placebo-controlled clinical trials enrolled more than 5000 pregnant women to assess the use of antibiotic treatment (including metronidazole) for bacterial vaginosis on the incidence of preterm delivery. Most studies did not show an increased risk for congenital anomalies or other adverse fetal outcomes following metronidazole exposure during pregnancy. Three studies conducted to assess the risk of infant cancer following metronidazole exposure during pregnancy did not show an increased risk; however, the ability of these studies to detect such a signal was limited. Metronidazole crosses the placental barrier and its effects on the human fetal organogenesis are not known. Reproduction studies have been performed in rats, rabbits, and mice at doses similar to the maximum recommended human dose based on body surface area comparisons.

Overdosage

Sourced from openFDA

Single oral doses of metronidazole, up to 15 g, have been reported in suicide attempts and accidental overdoses. Symptoms reported include nausea, vomiting, and ataxia. Oral metronidazole has been studied as a radiation sensitizer in the treatment of malignant tumors. Neurotoxic effects, including seizures and peripheral neuropathy, have been reported after 5 to 7 days of doses of 6 to 10.4 g every other day. Treatment of Overdosage: There is no specific antidote for metronidazole overdose; therefore, management of the patient should consist of symptomatic and supportive therapy.

Approval history

Sourced from openFDA
  • Dec 24, 1981NDANDA018657Baxter Hlthcare
  • Sep 29, 1983NDANDA018900B Braun
  • Aug 17, 1992NDANDA020208Bausch
  • May 3, 1995NDANDA020334Pfizer
  • Sep 20, 1995NDANDA020531Galderma Labs Lp
  • Sep 26, 1997NDANDA020743Bausch
  • Nov 24, 1998NDANDA020901Galderma Labs Lp
  • May 20, 2005NDANDA021806Teva Pharms

FDA shortages

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Reference statistics from the openFDA drug-shortage dataset. For a live view, consult the FDA database directly. Not clinical guidance.

  • Flagyl I.v. Rtu In Plastic Container, Injection, 500 mg/100 mL (NDC 0338-1055-48)Active
    Sponsor: Baxter Healthcare
    Updated
  • Metronidazole in Flexible Container, Injection, 500 mg/100 mL (NDC 0409-0152-24)Active
    Sponsor: InfoRLife SA · Reason: Other
    Updated
  • Metronidazole In Plastic Container, Injection, 500 mg/100 mL (NDC 47335-993-01)Active
    Sponsor: Gland Pharma Limited · Reason: Discontinuation of the manufacture of the drug
    Updated
  • Metronidazole, Injection, 500 mg/100 mL (NDC 25021-131-82)Active
    Sponsor: InfoRLife SA · Reason: Delay in shipping of the drug
    Updated

FAERS reports

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Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
64,039 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Drug Ineffective5,4188.5%
  2. 2Nausea4,7747.5%
  3. 3Diarrhoea4,1626.5%
  4. 4Off Label Use4,1296.4%
  5. 5Vomiting3,3475.2%
  6. 6Pyrexia3,2705.1%
  7. 7Drug Hypersensitivity3,1394.9%
  8. 8Pain3,0714.8%
  9. 9Abdominal Pain3,0024.7%
  10. 10Headache2,9474.6%
  11. 11Fatigue2,8704.5%
  12. 12Dyspnoea2,2463.5%
  13. 13Dizziness2,2353.5%
  14. 14Condition Aggravated2,1093.3%
  15. 15Malaise2,0323.2%

Literature

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Recent PubMed references pinned to Metronidazole as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 1,349 ClinicalTrials.gov registrations naming Metronidazole as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Metronidazole work?
Mechanism-of-action class: Unknown Cellular or Molecular Interaction.
What is Metronidazole used for?
According to FDA labeling, Metronidazole carries indications including: Symptomatic Trichomoniasis. Metronidazole tablets are indicated for the treatment of T.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Metronidazole?
Metronidazole is classified as Antiinfectives and antiseptics for local oral treatment, Imidazole derivatives, Nitroimidazole derivatives, Other chemotherapeutics, Nitroimidazole Antimicrobial, Unknown Cellular or Molecular Interaction, Decreased Protein Synthesis, DNA Integrity Alteration, Increased Cellular Death.
What are the brand names for Metronidazole?
Metronidazole is marketed under brand names including Flagyl, Likmez, MetroCream, MetroGel, MetroLotion, Noritate, Nuvessa, Nydamax.
What are the contraindications for Metronidazole?
Metronidazole labeling lists contraindications including: Hypersensitivity Metronidazole tablet are contraindicated in patients with a prior history of hypersensitivity to metronidazole or other nitroimidazole derivatives. In patients with trichomoniasis, metronidazole tablet are contraindicated during the first trimester of pregnancy (see PRECAUTIONS ).. Always consult the full prescribing information and a clinician.
Note. Data for metronidazole is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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