HomeNDC LookupIngredientsMetronidazole › 00025-1942-34
Flagyl metronidazole 375 mg Capsule, 100-count — NDC 00025-1942-34 package photo

Flagyl metronidazole 375 mg Capsule, 100-count

by Pfizer Laboratories Div Pfizer Inc · 100 BLISTER PACK in 1 CARTON (0025-1942-34) / 1 CAPSULE in 1 BLISTER PACK
NDC 00025-1942-34
🏷️ FDA NDC (as labeled) 0025-1942-34 billing pads the labeler segment with a zero
This package
Contains100-count Pack sizes2 compare ↓
Also comes in: 50 capsules 00025-1942-50
Rx only Brand On market Non-controlled
🗂️ Data synced Jul 24, 2026 · sources: openFDA · FDA label (DailyMed) · FDA Orange & Purple Book · First Databank · CMS NADAC, ASP, Medicare & Medicaid · RxNorm
📋 All sources & update times →

🆔 Identity & classification

FDA NDC (as labeled) 0025-1942-34
Product NDC 0025-1942
11-digit billing NDC 00025194234
RxCUI 199055, 687211
UNII 140QMO216E
Application # NDA020334
SPL Set ID a2883ca1-5a9a-4259-9d80-46ab67274384
Established class (EPC) Nitroimidazole Antimicrobial
Chemical class Nitroimidazoles
DEA schedule Non-controlled
Marketing category NDA
Marketing status On market
FDA listing status Listed (active directory)
Marketing start 1995-05-03
Route ORAL
Dosage form CAPSULE
Substance METRONIDAZOLE
GPI-14 16000035000107
GPI class Flagyl
GCN Seq No 023616
GCN 43035
HICL code 004157
Ingredient (HICL) Metronidazole
HIC1 code W
Therapeutic class — broad (HIC1) Anti-Infecting Agents
HIC2 code W4
Therapeutic class — intermediate (HIC2) Antiparasitics
HIC3 code W4E
Therapeutic class — specific (HIC3) Anaerobic Antiprotozoal-Antibacterial Agents
AHFS code 08:30.04.00
AHFS class Amebicides
FDB label name FLAGYL 375 CAPSULE
FDB brand name Flagyl
Legend status F — Federal legend — prescription drug or device
TE code (Orange Book) AB · RLD · RS
Why two NDCs? The FDA registers this code as 0025-1942-34 — a 4-4-2 layout, and that's what's printed on the package and shown on DailyMed. For insurance claims, every NDC is standardized to a uniform 11-digit 5-4-2 format by adding a zero to the labeler segment → 00025-1942-34. Same drug, same package — only the format differs.
Where does this data come from?
Identifiers from the FDA openFDA NDC Directory and Structured Product Labeling; RxCUI from RxNorm (NLM); GPI from Medi-Span; GCN / HIC / AHFS / legend from First Databank.

🏷️ RxNorm drug class

This medicine belongs to the Nitroimidazole Antimicrobial class.

Pharmacologic class Nitroimidazole Antimicrobial
Drug family (ATC) Nitroimidazole derivatives, Antiinfectives and antiseptics for local oral treatment, Other chemotherapeutics
Where does this data come from?
Therapeutic classes from RxNorm RxClass (U.S. National Library of Medicine) — Established Pharmacologic Class (FDA), ATC drug family (WHO) and mechanism of action, matched by this product’s RxCUI.

🏭 Manufacturer & labeler

LabelerPfizer Laboratories Div Pfizer Inc
Application holderPFIZER INC
FDA applicationNDA020334 (NDA)
Labeler code00025
First marketedMay 1995
Product typeHuman Prescription Drug
Portfolio242 products on file
The labeler markets the product; the application holder owns the FDA approval. They’re often the same company but can differ (e.g. a repackager or an authorized generic). A mailing address / phone appears here when the manufacturer includes it in the product’s FDA label (not all do).
Where does this data come from?
Labeler, application holder and registered establishment from the FDA openFDA NDC Directory and Drugs@FDA; address/contact from the product’s FDA label.

🩺 Clinical

Label name FLAGYL 375 CAPSULE Ingredient Metronidazole
📗 Our plain-language guide HelloPharmacist
  • This is one of the most important things to know about metronidazole. If you drink alcohol — or consume products containing propylene glycol — while taking it, you can have a prett...
  • Why do I have to avoid alcohol while taking this?
  • Yes, completely normal and actually really important. Trichomoniasis is a sexually transmitted infection, so even if your partner has no symptoms, they can still carry the parasite...
  • My partner and I both have to take this for trichomoniasis — is that normal?
📖 Read our full Metronidazole guide →
7
Nutrient depletion considerations

Metronidazole may be associated with lower levels of 7 nutrients — worth a chat with your pharmacist, not a cause for alarm.

An association is not a deficiency. Educational only — don't start or stop anything without professional guidance.
Where does this data come from?
Plain-language summary from MedlinePlus (U.S. National Library of Medicine); supplement & herbal interactions and nutrient depletion data from the Natural Medicines database; our full guide is HelloPharmacist editorial content.

💊 What it looks like

Color Gray / Green
ShapeCapsule
ImprintFLAGYL;375;mg
Size19 mm
ScoringNot scored
One label can cover several strengths, so colors may be combined — always confirm a loose pill against the dispensed prescription label or a pharmacist.
Where does this data come from?
Physical description (imprint, shape, color, scoring, coating) from this product’s FDA Structured Product Labeling (SPL), mirrored from DailyMed / openFDA.

🧪 Inactive Ingredients / Excipients

Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.

💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.

  • UNII 35SW5USQ3G
    A synthetic yellow dye used to color medicines. It helps make tablets, capsules, and liquids visually distinct so patients can easily identify their medication.
  • UNII 3P3ONR6O1S
    A synthetic green dye approved by the FDA for use in medicines and foods. It serves as a colorant to make the pill or liquid visually distinctive and help with product identification.
  • UNII XM0M87F357
    A dark iron oxide compound that gives medicines their black or dark color. It's used as a colorant in tablets and capsules to help identify the product and make it visually distinctive.
  • UNII 2G86QN327L
    Gelatin is a protein derived from animal collagen, commonly used in medicines as a gelling agent and capsule material. It helps create soft or hard capsule shells that hold and release medication, and can also thicken liquid formulations.
  • UNII 70097M6I30
    Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
  • UNII O8232NY3SJ
    A plant-based carbohydrate derived from corn kernels. It acts as a filler to add bulk, a binder to hold ingredients together, and a disintegrant to help the tablet break apart in your stomach for absorption.
  • UNII 15FIX9V2JP
    Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.

7 inactive ingredients listed in the exact product block matched to this NDC.

Where does this data come from?
Data sourced from official FDA Structured Product Labeling (SPL) via DailyMedingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.

Inactive ingredient FAQ

Are inactive ingredients the same for every manufacturer?
No. Inactive ingredients can differ by manufacturer, dosage form, strength, and package / product version.
Why might an inactive ingredient be missing?
Some SPLs do not provide a complete structured inactive-ingredient list, and older or unusual labels may only include the information in narrative text.
Can inactive ingredients matter?
Yes. They can matter for allergies, intolerances, dyes, gluten / lactose concerns, preservatives, and formulation differences — but confirm with a pharmacist or the manufacturer when it’s clinically important.

💲 Pricing

A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.

Price systemPer eachPer package
Retail pharmacies payNADAC · weekly Not in the retail survey — common for institutional, discontinued, or low-volume packs.
Medicaid paysCMS SDUD · 12 mo No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data.
Medicare drug plans payPart D · quarterly No Part D plan price is available for this NDC in our data.
ℹ️
No price is published for this exact package yet. CMS surveys NADAC per package size, so a different pack of the same drug often has one.
Try another pack size: 50 capsules
Where does this data come from?
NADAC (National Average Drug Acquisition Cost) is the CMS weekly pharmacy-acquisition-cost survey — what pharmacies pay. ASP (Average Sales Price) is the CMS Medicare Part B drug-payment file, published quarterly. Medicaid pays is computed by us from CMS State Drug Utilization Data (total reimbursed ÷ units, trailing 12 months) — gross of rebates and inclusive of dispensing fees, so it reflects what Medicaid paid, not an acquisition cost. Medicare drug plans pay is the median negotiated point-of-sale unit cost across plans listing this NDC in the CMS quarterly Prescription Drug Plan pricing files, before rebates. The VA pays is the federal contract price (FSS, and the statutory Big 4 ceiling where listed) from the VA National Acquisition Center pharmaceutical price file. All are free public government data; each measures a different payer, so the figures are not directly comparable.

🔁 Therapeutic equivalents

ProductLabelerPackNADAC/unitTEStatusPrice vs. this
Metronidazole 375 mg 62135-0836-50 Chartwell 50 capsules $7.308 AB Availability likely
Metronidazole 375 mg 46708-0435-30 Alembic 30 capsules AB FDA listed
Metronidazole 375 mg 62332-0018-30 Alembic 30 capsules AB FDA listed
Flagyl 375 mgthis 00025-1942-34 Pfizer 100 capsules AB FDA listed
About this product: this is the brand-name version. FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available.
Where does this data come from?
Equivalents are other NDCs of the same ingredient, form and route from the openFDA NDC Directory, ranked least-expensive-first by NADAC. Therapeutic-equivalence (AB) ratings come from the FDA Orange Book; biologics use the FDA Purple Book for biosimilar & interchangeable status.

Availability & generic status

🏛️
1995
On the market since
May 1995
📍
2026
Currently FDA-listed
31 years listed
🔓
·
Generic versions listed
see equivalents
Generic appears available

FDA-approved generic versions are listed, and recent pricing/market data suggests they may be available — see Therapeutic equivalents.

Where does this data come from?
Patents and exclusivity from the FDA Orange Book (small-molecule drugs), refreshed from public FDA data. Generic launch timing is an estimate, not a guarantee.

📊 Medicare Part D spend CMS · PART D · 2026 (Q1)

Medicare Part D (outpatient prescription) spending for Metronidazole (matched by generic name) — the program that covers self-administered drugs. 23 manufacturers.
⚠️ Drug-level data: CMS publishes Part D spending by drug, not by NDC — these figures combine every manufacturer, strength and package size sold under the name Metronidazole. CMS lists 4 products for this generic; we show the highest-spend one. That’s a different level of aggregation than the Medicaid card above, which is specific to this exact 11-digit NDC (pack size included), so the two aren’t directly comparable.
Period
Total Part D spend
$12.08M
Claims incl. refills
571.7K
Beneficiaries
500.3K
Spend / beneficiary
$24.15
Spend / claim
$21.13
Trend by period
💵 About the dollar figures: spending is what Part D plans paid before confidential manufacturer rebates, so the program’s real net cost is lower. A blank patient count means fewer than 11 people — CMS hides counts that small to protect privacy. Source: CMS Medicare Quarterly Part D Spending by Drug (data.cms.gov), updated quarterly.

🔬 Reported adverse events (FAERS)

Read carefully: FAERS reports are voluntary and unverified. Counts are not incidence, do not establish causation, are subject to reporting bias, and cannot be used to compare one drug to another. Shown for signal context only. Reports for Flagyl (this brand).

Top reported reactions

Nausea4,636
Diarrhoea4,050
Vomiting3,276
Pyrexia3,192
Drug Hypersensitivity3,145
Pain3,006
Abdominal Pain2,968

Age at onset

Neonate221
Infant82
Child252
Adolescent271
Adult5,396
Elderly2,515

Reporter sex

63,045 reports
Male · 38%
Female · 62%
Unknown · 0%

Serious outcomes

Hospitalization26,938
Death6,833
Life-threatening5,197
Disabling2,444
Reports over time (by year) — tap or hover for the count & year
2019 2021 2023 2026 5,610 0
Most recent year is provisional (FAERS lags ~3 months).
Where does this data come from?
Adverse-event reports from the FDA Adverse Event Reporting System (FAERS) via openFDA. FAERS reports are voluntary and unverified — counts are not incidence and don’t establish causation.

📦 Packaging — all sizes for this product

Package NDCDescription Marketing startStatus
00025-1942-34 You're viewing this 100 BLISTER PACK in 1 CARTON (0025-1942-34) / 1 CAPSULE in 1 BLISTER PACK 1995-05-03 Active
00025-1942-50 50 CAPSULE in 1 BOTTLE (0025-1942-50) 1995-05-03 Active

Pack size FAQ

What quantity is in NDC 00025-1942-34?
NDC 00025-1942-34 is a 100-count package — 100 blister pack in 1 carton / 1 capsule in 1 blister pack.
What is the difference between NDC 00025-1942-34 and NDC 00025-1942-50?
Both are Flagyl metronidazole 375 mg Capsule — the drug itself is identical. NDC 00025-1942-34 is the 100-count package, while NDC 00025-1942-50 is the 50 capsules package.
What NDC number is used to bill for this package of Flagyl metronidazole 375 mg Capsule?
Bill NDC 00025-1942-34 — the 11-digit billing format is 00025194234. Pharmacy and medical claims use the 11-digit form; the FDA label may print a shorter form of the same code.

🧭 About this NDC listing & data coverage

Finished prescription product
What data is (and isn’t) available for this NDC — tap to expand
NDC identity (package / product / labeler codes) ✓ Available
Labeler ✓ Available
Product & package description ✓ Available
Marketing category & status ✓ Available
Active ingredient / dosage form / route ✓ Available
FDA label (SPL via DailyMed) ✓ Available
Package photos ✓ Available
Inactive ingredients (structured) ✓ Available
NADAC pharmacy acquisition price (CMS) — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey.
Orange Book / therapeutic-equivalence data ✓ Available
HCPCS J-code billing crosswalk — Not published for this NDC Most self-administered / retail products have no J-code — that is normal.
Medicaid utilization (CMS SDUD) — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold.
“Not published” reflects what the public FDA / CMS / NLM sources provide for this exact package code — it is a property of the data feeds, not a judgment about the product.

Questions about this listing

Why is there no price listed?
The pricing shown on our NDC pages comes from CMS NADAC, a voluntary survey of retail community pharmacy invoices. CMS does not publish a NADAC for every NDC — packages outside the retail survey (institutional and hospital products, bulk packages, discontinued items, and many OTC items) may never receive one. A missing price reflects the survey's scope, not this product's actual cost, and does not mean the product is free or unavailable.
Is the NDC printed on the package the same as the 11-digit billing NDC?
Yes, they identify this exact package in different formats. The FDA registers it as 0025-1942-34, which is what is printed on the packaging and shown on DailyMed. Insurance claims use a fixed 11-digit 5-4-2 format, so the short segment is padded with a leading zero: 00025-1942-34, written without dashes as 00025194234. The Identity section at the top of this page lists every form of this code.
What do the three segments of this NDC mean?
In 00025-1942-34, the first segment (00025) is the labeler code FDA assigned to Pfizer Laboratories Div Pfizer Inc; the middle segment (1942) identifies this specific product — its ingredient, strength, and dosage form; and the last segment (34) identifies this exact package size and type. Together they name one specific package of one specific product.
Is this package still being marketed?
Yes, per the latest FDA NDC Directory data on this page: this package is listed as actively marketed, with no marketing end date reported by Pfizer Laboratories Div Pfizer Inc. Listing status can change — the directory data on this page refreshes weekly.
Does this product come in other package sizes?
Yes — the FDA directory lists 1 other package presentation of this same product, including 50 capsules (00025-1942-50). Each has its own NDC and its own page — see the package list near the top of this page.
Who lists this product with the FDA?
Pfizer Laboratories Div Pfizer Inc is the labeler of record for this NDC — the company under whose FDA-assigned code the package is listed. The labeler may be the manufacturer itself or a distributor marketing the product under its own code.
Do I need a prescription for this product?
This NDC is listed with FDA as a prescription product, so it is dispensed under a prescriber's order. Your pharmacist can tell you whether any over-the-counter forms of the same medication exist.
This page identifies an FDA-listed package (the NDC) and reports public regulatory and pricing data about the listing. It is reference information, not a medical recommendation — talk to your pharmacist or prescriber about your own medication.
Where does this data come from?
Listing facts (marketing category, packager status, marketing dates) from the FDA openFDA NDC Directory; label availability from DailyMed; pricing coverage from CMS NADAC; equivalence scope from the FDA Orange Book.

📄 Full prescribing information FDA SPL

The complete FDA label for this product — the official prescribing information, verbatim, section by section. Jump with a chip, search within the label, or expand everything.
🚨 Boxed Warning 39 words

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.

🎯 Indications and Usage ~3 min read

INDICATIONS AND USAGE Symptomatic Trichomoniasis . FLAGYL 375 capsules are indicated for the treatment of T. vaginalis infection in females and males when the presence of the trichomonad has been confirmed by appropriate laboratory procedures (wet smears and/or cultures). Asymptomatic Trichomoniasis .

FLAGYL 375 capsules are indicated in the treatment of asymptomatic T. vaginalis infection in females when the organism is associated with endocervicitis, cervicitis, or cervical erosion. Since there is evidence that presence of the trichomonad can interfere with accurate assessment of abnormal cytological smears, additional smears should be performed after eradication of the parasite. Treatment of Asymptomatic Sexual Partners .

T. vaginalis infection is a venereal disease. Therefore, asymptomatic sexual partners of treated patients should be treated simultaneously if the organism has been found to be present, in order to prevent reinfection of the partner. The decision as to whether to treat an asymptomatic male partner who has a negative culture or one for whom no culture has been attempted is an individual one.

In making this decision, it should be noted that there is evidence that a woman may become reinfected if her sexual partner is not treated. Also, since there can be considerable difficulty in isolating the organism from the asymptomatic male carrier, negative smears and cultures cannot be relied upon in this regard. In any event, the sexual partner should be treated with metronidazole in cases of reinfection.

Amebiasis . FLAGYL 375 capsules are indicated in the treatment of acute intestinal amebiasis (amebic dysentery) and amebic liver abscess. In amebic liver abscess, FLAGYL 375 capsules therapy does not obviate the need for aspiration or drainage of pus.

Anaerobic Bacterial Infections . FLAGYL 375 capsules are indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Indicated surgical procedures should be performed in conjunction with FLAGYL therapy.

In a mixed aerobic and anaerobic infection, antimicrobials appropriate for the treatment of the aerobic infection should be used in addition to FLAGYL 375 capsules. INTRA-ABDOMINAL INFECTIONS, including peritonitis, intra-abdominal abscess, and liver abscess, caused by Bacteroides species including the B. fragilis group ( B. fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, B. vulgatus ), Clostridium species, Eubacterium species, Peptococcus species, or Peptostreptococcus species. SKIN AND SKIN STRUCTURE INFECTIONS caused by Bacteroides species including the B. fragilis group, Clostridium species, Peptococcus species, Peptostreptococcus species, or Fusobacterium species.

GYNECOLOGIC INFECTIONS, including endometritis, endomyometritis, tubo-ovarian abscess, and postsurgical vaginal cuff infection, caused by Bacteroides species including the B. fragilis group, Clostridium species, Peptococcus species , Peptostreptococcus species, or Fusobacterium species. BACTERIAL SEPTICEMIA caused by Bacteroides species including the B. fragilis group or Clostridium species. BONE AND JOINT INFECTIONS (as adjunctive therapy) caused by Bacteroides species including the B. fragilis group.

CENTRAL NERVOUS SYSTEM (CNS) INFECTIONS, including meningitis and brain abscess, caused by Bacteroides species including the B. fragilis group. LOWER RESPIRATORY TRACT INFECTIONS, including pneumonia, empyema, and lung abscess, caused by Bacteroides species including the B. fragilis group. ENDOCARDITIS caused by Bacteroides species including the B. fragilis group.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of FLAGYL 375 capsules and other antibacterial drugs, FLAGYL 375 capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial t…

⏱️ Dosage and Administration ~2 min read

DOSAGE AND ADMINISTRATION Trichomoniasis In the Female: Seven-day course of treatment (375 mg two times daily for seven consecutive days). A seven-day course of treatment may minimize reinfection by protecting the patient long enough for the sexual contacts to obtain treatment. Pregnant patients should not be treated during the first trimester (see CONTRAINDICATIONS and PRECAUTIONS ).

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. In the Male: Treatment should be individualized as it is for the female.

Amebiasis: Adults: For acute intestinal amebiasis (acute amebic dysentery): 750 mg orally three times daily for 5 to 10 days. For amebic liver abscess: 750 mg orally three times daily for 5 to 10 days. Pediatric patients: 35 to 50 mg/kg/24 hours, divided into three doses, orally for 10 days.

Anaerobic Bacterial Infections In the treatment of most serious anaerobic infections, intravenous metronidazole is usually administered initially. The usual adult oral dosage is 7.5 mg/kg every 6 hours (approximately 500 mg for a 70 kg adult). A maximum of 4 g should not be exceeded during a 24-hour period.

The usual duration of therapy is 7 to 10 days; however, infections of the bone and joint, lower respiratory tract, and endocardium may require longer treatment. Dosage Adjustments Patients with Severe Hepatic impairment For amebiasis patients with severe (Child-Pugh C) hepatic impairment, pharmacokinetic modeling and simulation indicate that the FLAGYL 375 capsules dose should be reduced by 50%. Therefore, the dosage regimen of FLAGYL 375 capsules in Child Pugh C patients with amebiasis is 375 mg q8h for 5 to 10 days (see CLINICAL PHARMACOLOGY and PRECAUTIONS ).

For trichomoniasis patients with severe (Child-Pugh C) hepatic impairment, pharmacokinetic modeling and simulation indicate that the frequency of metronidazole administration should be reduced from every 12 hours to every 24 hours. Therefore, the dosage regiment of FLAGYL 375 capsules in Child Pugh C patients with trichomoniasis is 375 mg q24h for 7 days (see CLINICAL PHARMACOLOGY and PRECAUTIONS ). Patients Undergoing Hemodialysis Hemodialysis removes significant amounts of metronidazole and its metabolites from systemic circulation.

The clearance of metronidazole will depend on the type of dialysis membrane used, the duration of the dialysis session, and other factors. If the administration of metronidazole cannot be separated from a hemodialysis session, supplementation of metronidazole dosage following the hemodialysis session should be considered, depending on the patient's clinical situation (see CLINICAL PHARMACOLOGY ).

Contraindications 165 words

CONTRAINDICATIONS Hypersensitivity FLAGYL 375 capsules are contraindicated in patients with a prior history of hypersensitivity to metronidazole or other nitroimidazole derivatives. In patients with trichomoniasis, FLAGYL 375 capsules are contraindicated during the first trimester of pregnancy (see PRECAUTIONS ). Psychotic Reaction with Disulfiram Use of oral metronidazole is associated with psychotic reactions in alcoholic patients who were using disulfiram concurrently.

Do not administer metronidazole to patients who have taken disulfiram within the last two weeks (see PRECAUTIONS, Drug Interactions ). Interaction with Alcohol Use of oral metronidazole is associated with a disulfiram-like reaction to alcohol, including abdominal cramps, nausea, vomiting, headaches, and flushing. Discontinue consumption of alcohol or products containing propylene glycol during and for at least three days after therapy with metronidazole (see PRECAUTIONS, Drug Interactions ).

Cockayne Syndrome FLAGYL 375 capsules are contraindicated in patients with Cockayne syndrome. Severe irreversible hepatotoxicity/acute liver failure with fatal outcomes have been reported after initiation of metronidazole in patients with Cockayne syndrome (see ADVERSE REACTIONS ) .

⚠️ Warnings ~1 min read

WARNINGS 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 FLAGYL capsules 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.

Symptoms can occur within hours of dose administration and generally resolve after metronidazole therapy is discontinued. The appearance of abnormal neurologic signs and symptoms demands the prompt evaluation of the benefit/risk ratio of the continuation of therapy (see ADVERSE REACTIONS ).

🤒 Adverse Reactions ~2 min read

ADVERSE REACTIONS 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; 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.

Cardiovascular: QT prolongation has been reported, particularly when metronidazole was administered with drugs with the potential for prolonging the QT interval. Flattening of the T-wave may be seen in electrocardiographic tracings. Hypersensitivity: Toxic epidermal necrolysis (TEN), Stevens-Johnson Syndrome (SJS), drug reaction with eosinophilia and systemic symptoms (DRESS), acute generalized exanthematous pustulosis (AGEP) (see WARNINGS ), urticaria, erythematous rash, flushing, nasal congestion, dryness of the mouth (or vagina or vulva), and fever.

Renal: Dysuria, cystitis, polyuria, incontinence, and a sense of pelvic pressure. Instances of darkened urine have been reported by approximately one patient in 100,000. Although the pigment which is probably responsible for this phenomenon has not been positively identified, it is almost certainly a metabolite of metronidazole and seems to have no clinical significance.

Hepatic: Cases of severe irreversible hepatotoxicity/acute liver failure, including cases with fatal outcomes with very rapid onset after initiation of systemic use of metronidazole, have been reported in patients with Cockayne syndrome (latency from drug start to signs of liver failure as short as 2 days) (see CONTRAINDICATIONS ). Other: Proliferation of Candida in the vagina, dyspareunia, decrease of libido, proctitis, and fleeting joint pains sometimes resembling "serum sickness." Rare cases of pancreatitis, which generally abated on withdrawal of the drug, have been reported.

Patients with Crohn's disease are known to have an increased incidence of gastrointestinal and certain extraintestinal cancers. There have been some reports in the medical literature of breast and colon cancer in Crohn's disease patients who have been treated with metronidazole at high doses for extended periods of time. A cause and effect relationship has not been established.

Crohn's disease is not an approved indication for FLAGYL 375 capsules.

🔄 Drug Interactions ~2 min read

Drug interactions Disulfiram Psychotic reactions have been reported in alcoholic patients who are using metronidazole and disulfiram concurrently. Metronidazole should not be given to patients who have taken disulfiram within the last 2 weeks (see CONTRAINDICATIONS ). Alcoholic Beverages Abdominal cramps, nausea, vomiting, headaches, and flushing may occur if alcoholic beverages or products containing propylene glycol are consumed during or following metronidazole therapy (see CONTRAINDICATIONS ).

Warfarin and other Oral Anticoagulants Metronidazole has been reported to potentiate the anticoagulant effect of warfarin and other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time. When FLAGYL 375 capsules is prescribed for patients on this type of anticoagulant therapy prothrombin time and INR should be carefully monitored. Lithium In patients stabilized on relatively high doses of lithium, short-term metronidazole therapy has been associated with elevation of serum lithium and, in a few cases, signs of lithium toxicity.

Serum lithium and serum creatinine levels should be obtained several days after beginning metronidazole to detect any increase that may precede clinical symptoms of lithium intoxication. Busulfan Metronidazole has been reported to increase plasma concentrations of busulfan, which can result in an increased risk for serious busulfan toxicity. Metronidazole should not be administered concomitantly with busulfan unless the benefit outweighs the risk.

If no therapeutic alternatives to metronidazole are available, and concomitant administration with busulfan is medically needed, frequent monitoring of busulfan plasma concentration should be performed and the busulfan dose should be adjusted accordingly. Drugs that Inhibit CYP450 Enzymes The simultaneous administration of drugs that decrease microsomal liver enzyme activity, such as cimetidine, may prolong the half-life and decrease plasma clearance of metronidazole. Drugs that Induce CYP450 Enzymes The simultaneous administration of drugs that induce microsomal liver enzymes, such as phenytoin or phenobarbital, may accelerate the elimination of metronidazole, resulting in reduced plasma levels; impaired clearance of phenytoin has also been reported.

Drugs that Prolong the QT interval QT prolongation has been reported, particularly when metronidazole was administered with drugs with the potential for prolonging the QT interval.

🔄 Drug / Laboratory Test Interactions 84 words

Drug/Laboratory Test Interactions Metronidazole may interfere with certain types of determinations of serum chemistry values, such as aspartate aminotransferase (AST, SGOT), alanine aminotransferase (ALT, SGPT), lactate dehydrogenase (LDH), triglycerides, and glucose hexokinase. Values of zero may be observed. All of the assays in which interference has been reported involve enzymatic coupling of the assay to oxidation-reduction of nicotinamide adenine dinucleotide (NAD + ⇆ NADH).

Interference is due to the similarity in absorbance peaks of NADH (340 nm) and metronidazole (322 nm) at pH 7.

🤰 Pregnancy 214 words

Pregnancy: Teratogenic effects: There are no adequate and well-controlled studies of FLAGYL 375 capsules 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 finding 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 abnormalities 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.

There was no evidence of harm to the fetus due to metronidazole.

🧒 Pediatric Use 18 words

Pediatric use Safety and effectiveness in pediatric patients have not been established, except in the treatment of amebiasis.

🧓 Geriatric Use 44 words

Geriatric use In geriatric patients, monitoring for metronidazole associated adverse events is recommended (see CLINICAL PHARMACOLOGY and PRECAUTIONS ). Decreased liver function in geriatric patients can result in increased concentrations of metronidazole that may necessitate adjustment of metronidazole dosage (see DOSAGE AND ADMINISTRATION ).

🆘 Overdosage 89 words

OVERDOSAGE 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.

🧬 Clinical Pharmacology ~3 min read

CLINICAL PHARMACOLOGY Absorption Disposition of metronidazole in the body is similar for both oral and intravenous dosage forms. FLAGYL 375 capsules have been shown to have a rate and extent of absorption similar to metronidazole tablets (FLAGYL) and were bioequivalent at an equal single dose of 750 mg. In a study conducted with 23 adult, healthy, female volunteers, oral administration of two 375 mg FLAGYL capsules under fasted conditions produced a mean (±1 SD) peak plasma concentration (C max ) of 21.4 (±2.8) mcg/mL with a mean T max of 1.6 (± 0.7) hours and a mean area under the plasma concentration-time curve (AUC) of 223 (±44) mcg∙hr/mL.

In the same study, three 250 mg FLAGYL tablets produced a mean C max of 20.4 (± 3.8) mcg/mL with a mean T max of 1.4 (± 0.4) hours and a mean AUC of 218 (± 50) mcg∙hr/mL. Administration of FLAGYL 375 capsules with food does not affect the extent of absorption of metronidazole; however, the presence of food results in a lower C max and a delayed T max compared to fasted conditions. In a study of 14 healthy, adult, female volunteers, administration of FLAGYL 375 capsules under fasting conditions produced a mean C max of 10.9 (± 1.5) mcg/mL, a mean T max of 1.5 (± 1.4) hours, and a mean AUC of 110 (± 34) mcg∙hr/mL compared to a mean C max of 8.6 (± 1.6) mcg/mL, a mean T max of 4.2 (± 1.7) hours, and a mean AUC of 99 (± 14) mcg∙hr/mL under fed conditions.

Distribution Metronidazole is the major component appearing in the plasma, with lesser quantities of metabolites also being present. Less than 20% of the circulating metronidazole is bound to plasma proteins. Metronidazole appears in cerebrospinal fluid, saliva, and breast milk in concentrations similar to those found in plasma.

Bactericidal concentrations of metronidazole have also been detected in pus from hepatic abscesses. Metabolism/Excretion The major route of elimination of metronidazole and its metabolites is via the urine (60% to 80% of the dose), with fecal excretion accounting for 6% to 15% of the dose. The metabolites that appear in the urine result primarily from side-chain oxidation [1-(ß-hydroxyethyl)-2-hydroxymethyl-5-nitroimidazole and 2-methyl-5-nitroimidazole-1-yl-acetic acid] and glucuronide conjugation, with unchanged metronidazole accounting for approximately 20% of the total.

Both the parent compound and the hydroxyl metabolite possess in vitro antimicrobial activity against most strains of anaerobic bacteria and in vitro trichomonacidal activity. Renal clearance of metronidazole is approximately 10 mL/min/1.73 m 2 . The average elimination half-life of metronidazole in healthy subjects is eight hours.

Renal Impairment Decreased renal function does not alter the single-dose pharmacokinetics of metronidazole. Subjects with end-stage renal disease (ESRD; CL CR =8.1±9.1 mL/min) and who received a single intravenous infusion of metronidazole 500 mg had no significant change in metronidazole pharmacokinetics but had 2-fold higher Cmax of hydroxy-metronidazole and 5-fold higher Cmax of metronidazole acetate, compared to healthy subjects with normal renal function (CL CR =126±16 mL/min). Thus, on account of the potential accumulation of metronidazole metabolites in ESRD patients, monitoring for metronidazole associated adverse events is recommended (see PRECAUTIONS ).

Effect of Dialysis Following a single intravenous infusion or oral dose of metronidazole 500 mg, the clearance of metronidazole was investigated in ESRD subjects undergoing hemodialysis or continuous ambulatory peritoneal dialysis (CAPD). A hemodialysis session lasting for 4 to 8 hours removed 40% to 65% of the administered metronidazole dose, depending on the type of dialyzer membrane used and the duration of the dialysis session. If the administration of metronidazole cannot be separated from the dialysis session, supplementation of metronidazole dose following hemodialysis should be considered (see DOSAGE AND ADMINISTRATION ).

A peritoneal dialysis session la…

📦 How Supplied / Storage and Handling 54 words

HOW SUPPLIED FLAGYL 375 capsules have an iron gray opaque body imprinted with 375 mg and a light green opaque cap imprinted with FLAGYL, supplied as: NDC Number Size 0025-1942-34 Carton of 100 unit dose Storage and Stability: Store at controlled room temperature 15–25°C (59–77°F). Dispense in a well-closed container with a child-resistant closure.

📦 Storage and Handling 19 words

Storage and Stability: Store at controlled room temperature 15–25°C (59–77°F). Dispense in a well-closed container with a child-resistant closure.

📋 Description 66 words

DESCRIPTION FLAGYL (metronidazole) capsules, 375 mg is an oral formulation of the synthetic nitroimidazole antimicrobial agent, 2-methyl-5-nitro-1 H -imidazole-1-ethanol, which has the following structural formula: FLAGYL (metronidazole) capsules, 375 mg, (indicated below as FLAGYL 375 capsules) contain 375 mg of metronidazole USP. Inactive ingredients include corn starch, magnesium stearate, gelatin, black iron oxide, titanium dioxide, FD&C Green No. 3, and D&C Yellow No.

10. Chemical Structure

💬 Information for Patients 217 words

Information for patients Interaction with Alcohol Discontinue consumption of alcoholic beverages or products containing propylene glycol while taking FLAGYL 375 capsules and for at least three days afterward because abdominal cramps, nausea, vomiting, headaches, and flushing may occur (see CONTRAINDICATIONS and PRECAUTIONS, Drug Interactions ). Treatment of Bacterial and Parasitic Infections Patients should be counseled that FLAGYL 375 should only be used to treat bacterial and parasitic infections. They do not treat viral infections (e.g., the common cold).

When FLAGYL 375 is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by FLAGYL 375 in the future. Severe Cutaneous Adverse Reactions Advise patients that FLAGYL capsules may increase the risk of serious and sometimes fatal dermatologic reactions, including TEN, SJS, and DRESS.

Instruct the patient to be alert for skin rash, blisters, fever or other signs and symptoms of these hypersensitivity reactions. Advise patients to stop FLAGYL capsules immediately if they develop any type of rash and seek medical attention.

Source: FDA Structured Product Labeling, mirrored from DailyMed / openFDA. Prefer the government’s original formatting? View this label on DailyMed ↗
For educational and professional reference only — not medical advice. Pricing reflects published NADAC and CMS ASP (free public data) and may differ from your acquisition cost; always verify before billing or dispensing.