Label: METRONIDAZOLE gel

  • NDC Code(s): 51672-4215-3, 51672-4215-6, 51672-4215-9
  • Packager: Taro Pharmaceuticals U.S.A., Inc.
  • Category: HUMAN PRESCRIPTION DRUG LABEL
  • DEA Schedule: None
  • Marketing Status: Abbreviated New Drug Application

Drug Label Information

Updated April 26, 2019

If you are a consumer or patient please visit this version.

  • HIGHLIGHTS OF PRESCRIBING INFORMATION
    These highlights do not include all the information needed to use METRONIDAZOLE GEL safely and effectively. See full prescribing information for METRONIDAZOLE GEL

    METRONIDAZOLE gel, for topical use
    Initial U.S. Approval: 1963

    INDICATIONS AND USAGE

    Metronidazole Gel USP, 1% is a nitroimidazole indicated for the topical treatment of inflammatory lesions of rosacea. (1)

    DOSAGE AND ADMINISTRATION

    • Not for oral, ophthalmic or intravaginal use.
    • Apply and rub in a thin film of metronidazole once daily to affected area(s). (2)
    • Treated areas should be cleansed before the application of metronidazole. (2)
    • Cosmetics may be applied after the application of metronidazole. (2)

    DOSAGE FORMS AND STRENGTHS

    Gel, 1%. (3)

    CONTRAINDICATIONS

    Metronidazole Gel USP, 1% is contraindicated in those patients with a history of hypersensitivity to metronidazole or to any other ingredient in this formulation. (4)

    WARNINGS AND PRECAUTIONS

    • Peripheral neuropathy, characterized by numbness or paresthesia of an extremity has been reported in patients treated with systemic metronidazole. Although not evident in clinical trials for topical metronidazole, peripheral neuropathy has been reported with the post approval use. The appearance of abnormal neurologic signs should prompt immediate reevaluation of metronidazole therapy. (5.1)
    • Metronidazole is a nitroimidazole and should be used with care in patients with evidence of, or history of, blood dyscrasia. (5.2)
    • If dermatitis occurs, patients may need to discontinue use. (5.3)
    • Topical metronidazole has been reported to cause tearing of the eyes. Therefore, contact with the eyes should be avoided. (5.4)

    ADVERSE REACTIONS

    Most common adverse reactions (incidence > 2%) are nasopharyngitis, upper respiratory tract infection, and headache (6)


    To report SUSPECTED ADVERSE REACTIONS, contact Taro Pharmaceuticals U.S.A., Inc. at 1-866-923-4914 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

    DRUG INTERACTIONS

    Oral metronidazole has been reported to potentiate the anticoagulant effect of coumarin and warfarin, resulting in a prolongation of prothrombin time. Drug interactions should be kept in mind when metronidazole is prescribed for patients who are receiving anticoagulant treatment, although they are less likely to occur with topical metronidazole administration because of low absorption. (7)

    See 17 for PATIENT COUNSELING INFORMATION.

    Revised: 4/2019

  • Table of Contents
  • 1 INDICATIONS AND USAGE

    Metronidazole Gel USP, 1% is indicated for the topical treatment of inflammatory lesions of rosacea.

  • 2 DOSAGE AND ADMINISTRATION

    Apply and rub in a thin film of metronidazole once daily to affected area(s).

    A gentle cleanser should be used before the application of metronidazole.

    Cosmetics may be applied after the application of metronidazole. Not for oral, ophthalmic or intravaginal use.

  • 3 DOSAGE FORMS AND STRENGTHS

    Gel, 1%. Metronidazole is a colorless to slightly yellow gel. Each gram of metronidazole contains 10 mg (1%) of metronidazole.

  • 4 CONTRAINDICATIONS

    Metronidazole Gel USP, 1% is contraindicated in patients with a history of hypersensitivity to metronidazole or to any other ingredient in the formulation.

  • 5 WARNINGS AND PRECAUTIONS

    5.1 Neurologic Disease

    Peripheral neuropathy, characterized by numbness or paresthesia of an extremity has been reported in patients treated with systemic metronidazole. Although not evident in clinical trials for topical metronidazole, peripheral neuropathy has been reported with the post approval use. The appearance of abnormal neurologic signs should prompt immediate reevaluation of metronidazole therapy. Metronidazole should be administered with caution to patients with central nervous system diseases.

    5.2 Blood Dyscrasias

    Metronidazole is a nitroimidazole; use with care in patients with evidence of, or history of, blood dyscrasia.

    5.3 Contact Dermatitis

    Irritant and allergic contact dermatitis have been reported. If dermatitis occurs, patients may need to discontinue use.

    5.4 Eye Irritation

    Topical metronidazole has been reported to cause tearing of the eyes. Avoid contact with the eyes.

  • 6 ADVERSE REACTIONS

    6.1 Clinical Trials Experience

    Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

    In a controlled clinical trial, 557 patients used metronidazole gel USP, 1% and 189 patients used the gel vehicle once daily for up to 10 weeks. The following table summarizes selected adverse reactions that occurred at a rate of 1%:

    Table 1: Adverse Reactions That Occurred at a Rate of ≥1%
    System Organ Class/Preferred TermMetronidazole Gel USP, 1%Gel Vehicle
    N=557N=189
    Patients with at least one AE
        Number (%) of Patients
    186 (33.4)51 (27.0)
    Infections and infestations76 (13.6)28 (14.8)
      Bronchitis6 (1.1)3 (1.6)
      Influenza8 (1.4)1 (0.5)
      Nasopharyngitis17 (3.1)8 (4.2)
      Sinusitis8 (1.4)3 (1.6)
      Upper respiratory tract infection14 (2.5)4 (2.1)
      Urinary tract infection6 (1.1)1 (0.5)
      Vaginal mycosis1 (0.2)2 (1.1)
    Musculoskeletal and connective tissue disorders19 (3.4)5 (2.6)
      Back pain3 (0.5)2 (1.1)
    Neoplasms4 (0.7)2 (1.1)
      Basal cell carcinoma1 (0.2)2 (1.1)
    Nervous system disorders18 (3.2)3 (1.6)
      Headache12 (2.2)1 (0.5)
    Respiratory, thoracic and mediastinal disorders22 (3.9)5 (2.6)
      Nasal congestion6 (1.1)3 (1.6)
    Skin and subcutaneous tissue disorders36 (6.5)12 (6.3)
      Contact dermatitis7 (1.3)1 (0.5)
      Dry skin6 (1.1)3 (1.6)
    Vascular disorders8 (1.4)1 (0.5)
      Hypertension6 (1.1)1 (0.5)
    Table 2: Local Cutaneous Signs and Symptoms of Irritation That Were Worse Than Baseline
    Metronidazole Gel USP, 1%Gel Vehicle
    Sign/SymptomN=544N=184
    Dryness138 (25.4)63 (34.2)
      Mild93 (17.1)41 (22.3)
      Moderate42 (7.7)20 (10.9)
      Severe3 (0.6)2 (1.1)
    Scaling134 (24.6)60 (32.6)
      Mild88 (16.2)32 (17.4)
      Moderate43 (7.9)27 (14.7)
      Severe3 (0.6)1 (0.5)
    Pruritus86 (15.8)35 (19.0)
      Mild53 (9.7)21 (11.4)
      Moderate27 (5.0)13 (7.1)
      Severe6 (1.1)1 (0.5)
    Stinging/burning56 (10.3)28 (15.2)
      Mild39 (7.2)18 (9.8)
      Moderate7 (1.3)9 (4.9)
      Severe10 (1.8)1 (0.5)

    The following additional adverse experiences have been reported with the topical use of metronidazole: skin irritation, transient redness, metallic taste, tingling or numbness of extremities, and nausea.

    6.2 Post Marketing Experience

    The following adverse reaction has been identified during post approval use of topical metronidazole: peripheral neuropathy. Because this reaction is reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate the frequency or establish a causal relationship to drug exposure.

  • 7 DRUG INTERACTIONS

    Oral metronidazole has been reported to potentiate the anticoagulant effect of coumarin and warfarin, resulting in a prolongation of prothrombin time. Drug interactions should be kept in mind when metronidazole is prescribed for patients who are receiving anticoagulant treatment, although they are less likely to occur with topical metronidazole administration because of low absorption.

  • 8 USE IN SPECIFIC POPULATIONS

    8.1 Pregnancy

    Teratogenic Effects: Pregnancy Category B.

    There are no adequate and well-controlled studies with the use of metronidazole in pregnant women.

    Metronidazole crosses the placental barrier and enters the fetal circulation rapidly. No fetotoxicity was observed after oral administration of metronidazole in rats or mice at 200 and 20 times, respectively, the expected clinical dose. However, oral metronidazole has shown carcinogenic activity in rodents. Because animal reproduction studies are not always predictive of human response, metronidazole should be used during pregnancy only if clearly needed.

    8.3 Nursing Mothers

    After oral administration, metronidazole is secreted in breast milk in concentrations similar to those found in the plasma. Even though blood levels taken after topical metronidazole application are significantly lower than those achieved after oral metronidazole a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother and the risk to the infant.

    8.4 Pediatric Use

    Safety and effectiveness in pediatric patients have not been established.

    8.5 Geriatric Use

    Sixty-six subjects aged 65 years and older were treated with metronidazole gel USP, 1% in the clinical study. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.

  • 10 OVERDOSAGE

    There are no reported human experiences with overdosage of metronidazole. Topically applied metronidazole can be absorbed in sufficient amount to produce systemic effects.

  • 11 DESCRIPTION

    Metronidazole Gel USP, 1% contains metronidazole, USP. Chemically, metronidazole is 2-methyl-5-nitro-1 H-imidazole- 1-ethanol. The molecular formula for metronidazole is C6H9N3O3. It has the following structural formula:

    Chemical Structure

    Metronidazole has a molecular weight of 171.16. It is a white to pale yellow crystalline powder. It is slightly soluble in alcohol and has solubility in water of 10 mg/mL at 20°C. Metronidazole belongs to the nitroimidazole class of compounds. Metronidazole is a colorless to slightly yellow gel; each gram contains 10 mg of metronidazole in a base of alcohol (9.3% w/w), edetate disodium, hydroxyethylcellulose, polyethylene glycol 400, propylene glycol, sorbic acid, and purified water.

  • 12 CLINICAL PHARMACOLOGY

    12.1 Mechanism of Action

    The mechanism of action of metronidazole in the treatment of rosacea is unknown.

    12.2 Pharmacodynamics

    The pharmacodynamics of metronidazole in association with the treatment of rosacea are unknown.

    12.3 Pharmacokinetics

    Topical administration of a one gram dose of metronidazole to the face of 13 patients with moderate to severe rosacea once daily for 7 days resulted in a mean ± SD Cmax of metronidazole of 32 ± 9 ng/mL. The mean ± SD AUC(0-24) was 595 ± 154 ng*hr/mL.

    The mean Cmax and AUC(0-24) are less than 1% of the value reported for a single 250 mg oral dose of metronidazole. The time to maximum plasma concentration (Tmax) was 6 to 10 hours after topical application.

  • 13 NONCLINICAL TOXICOLOGY

    13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

    Metronidazole has shown evidence of carcinogenic activity in a number of studies involving chronic, oral administration in mice and rats, but not in studies involving hamsters.

    In several long-term studies in mice, oral doses of approximately 225 mg/m2/day or greater (approximately 37 times the human topical dose on a mg/m2 basis) were associated with an increase in pulmonary tumors and lymphomas. Several long-term oral studies in the rat have shown statistically significant increases in mammary and hepatic tumors at doses >885 mg/m2/day (144 times the human dose).

    Metronidazole has shown evidence of mutagenic activity in several in vitro bacterial assay systems. In addition, a dose-related increase in the frequency of micronuclei was observed in mice after intraperitoneal injections. An increase in chromosomal aberrations in peripheral blood lymphocytes was reported in patients with Crohn's disease who were treated with 200 to 1200 mg/day of metronidazole for 1 to 24 months. However, in another study, no increase in chromosomal aberrations in circulating lymphocytes was observed in patients with Crohn's disease treated with the drug for 8 months.

    In one published study, using albino hairless mice, intraperitoneal administration of metronidazole at a dose of 45 mg/m2/day (approximately 7 times the human topical dose on a mg/m2 basis) was associated with an increase in ultraviolet radiation induced skin carcinogenesis. Neither dermal carcinogenicity nor photocarcinogenicity studies have been performed with metronidazole gel USP, 1% or any marketed metronidazole formulations.

  • 14 CLINICAL STUDIES

    In a randomized, vehicle-controlled trial, 746 subjects with rosacea were treated with metronidazole gel USP, 1% or gel vehicle once daily for 10 weeks. Most subjects had "moderate" rosacea at baseline. Efficacy was determined by recording reduction in inflammatory lesion counts and success rate in the Investigator Global Assessment (percentage of subjects "clear" and "almost clear" of rosacea at the end of the study). The scale is based on the following definitions:

    Table 3: Investigator Global Assessment Scale
    ScoreGradeDefinition
    0ClearNo signs or symptoms present; at most, mild erythema
    1Almost ClearVery mild erythema present. Very few small papules/pustules
    2MildMild erythema. Several small papules/pustules
    3ModerateModerate erythema. Several small or large papules/pustules, and up to 2 nodules
    4SevereSevere erythema. Numerous small and/or large papules/pustules, up to several nodules

    The results are shown in the following table:

    Table 4: Inflammatory Lesion Counts and Global Scores in a Clinical Trial of Rosacea
    Metronidazole Gel USP, 1%Vehicle
    NResults N
    (%)
    NResults N
    (%)
    Inflammatory lesions557189
    Baseline, mean count18.318.4
    Week-10, mean count8.912.8
    Reduction9.4 (50.7)5.6 (32.6)
    Investigator Global Assessment557189
    Subject clear or almost clear214 (38.42)52 (27.51)
    Subject with no change159 (28.5)77 (40.7)

    Subjects treated with metronidazole gel USP, 1% experienced a mean reduction of 9.4 inflammatory lesions in the Week-10 LOCF group, compared to a reduction of 5.6 for those treated with vehicle, or a difference in means of 3.8 lesions.

    The contribution to efficacy of individual components of the vehicle has not been established.

  • 16 HOW SUPPLIED/STORAGE AND HANDLING

    Metronidazole Gel USP, 1% is colorless to slightly yellow in color, and supplied as follows:

    45 g tube - (NDC 51672-4215-6)

    60 g tube - (NDC 51672-4215-3)

    55 g pump - (NDC 51672-4215-9)

    Storage Conditions: Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].

  • 17 PATIENT COUNSELING INFORMATION

    Patients using Metronidazole Gel USP, 1% should receive the following information and instructions:

    1. This medication is to be used as directed.
    2. It is for external use only.
    3. Avoid contact with the eyes.
    4. Cleanse affected area(s) before applying Metronidazole Gel USP, 1%.
    5. This medication should not be used for any condition other than that for which it is prescribed.
    6. Keep out of reach of children.
    7. Patients should report any adverse reaction to their physicians.
  • SPL UNCLASSIFIED SECTION

    Rx Only

    Mfd. by: Taro Pharmaceutical Industries Ltd.
    Haifa Bay, Israel 2624761
    Dist. by: Taro Pharmaceuticals U.S.A., Inc.
    Hawthorne, NY 10532

    Revised: April 2019
    21333-0419-0
    782

  • PRINCIPAL DISPLAY PANEL

    PRINCIPAL DISPLAY PANEL - 45 g Tube Carton

    NDC 51672-4215-6

    Metronidazole
    Gel USP, 1%

    45 g

    FOR TOPICAL USE ONLY.
    NOT FOR ORAL, OPHTHALMIC OR INTRAVAGINAL USE.

    Rx only

    Keep this and all medications out of the reach of children.

    TARO

    PRINCIPAL DISPLAY PANEL - 45 g Tube Carton
  • INGREDIENTS AND APPEARANCE
    METRONIDAZOLE 
    metronidazole gel
    Product Information
    Product TypeHUMAN PRESCRIPTION DRUGItem Code (Source)NDC:51672-4215
    Route of AdministrationTOPICAL
    Active Ingredient/Active Moiety
    Ingredient NameBasis of StrengthStrength
    Metronidazole (UNII: 140QMO216E) (Metronidazole - UNII:140QMO216E) Metronidazole10 mg  in 1 g
    Inactive Ingredients
    Ingredient NameStrength
    alcohol (UNII: 3K9958V90M)  
    edetate disodium (UNII: 7FLD91C86K)  
    polyethylene glycol 400 (UNII: B697894SGQ)  
    propylene glycol (UNII: 6DC9Q167V3)  
    water (UNII: 059QF0KO0R)  
    sorbic acid (UNII: X045WJ989B)  
    Product Characteristics
    ColorYELLOW (clear to yellow) Score    
    ShapeSize
    FlavorImprint Code
    Contains    
    Packaging
    #Item CodePackage DescriptionMarketing Start DateMarketing End Date
    1NDC:51672-4215-61 in 1 CARTON04/09/2019
    145 g in 1 TUBE; Type 0: Not a Combination Product
    2NDC:51672-4215-31 in 1 CARTON04/09/2019
    260 g in 1 TUBE; Type 0: Not a Combination Product
    3NDC:51672-4215-91 in 1 CARTON04/09/2019
    355 g in 1 BOTTLE, PUMP; Type 0: Not a Combination Product
    Marketing Information
    Marketing CategoryApplication Number or Monograph CitationMarketing Start DateMarketing End Date
    ANDAANDA20465104/09/2019
    Labeler - Taro Pharmaceuticals U.S.A., Inc. (145186370)
    Establishment
    NameAddressID/FEIBusiness Operations
    Taro Pharmaceutical Industries Ltd.600072078MANUFACTURE(51672-4215)