metronidazole
Metronidazole is a nitroimidazole antimicrobial used to treat Abscess, Amebiasis, Bacteroides Infections, Bacterial Endocarditis.
Nitroimidazole Antimicrobial · by Padagis Israel
Generic of Vandazole
⚠ FDA reports a current shortage of the injection form — availability differs between suppliers — see drug shortages →Key facts
- Active ingredient
- Metronidazole
- Drug class
- Nitroimidazole Antimicrobial
- Form
- Topical, Injectable, Solution, Tablet
- Strength
- Metronidazole 0.75%
- Type
- Prescription (Rx)
- Brand or generic
- Generic
- May treat
- abscess, amebiasis, bacteroides infections
- Manufacturer
- Padagis Israel
- Half-life
- about 8 hours (how long it stays in your system)
- What the pharmacy pays
- ~$0.10 per gm — not your price
- FDA application
- ANDA211786
What is Metronidazole?
From the FDA label:Metronidazole Vaginal Gel is the intravaginal dosage form of the synthetic antibacterial agent, metronidazole, USP at a concentration of 0.75%. Metronidazole is a member of the imidazole class of antibacterial agents and is classified therapeutically as an antiprotozoal and antibacterial agent. Chemically, metronidazole is a 2-methyl-5-nitroimidazole-1-ethanol. It has a chemical formula of C 6 H 9 N 3 O 3 , a molecular weight of 171.16, and has the following structure: Metronidazole Vaginal Gel is a gelled, purified water solution, containing metronidazole at a concentration of 7.5 mg/g (0.75%). The gel is formulated at pH 4.0. The gel also contains carbomer 974P, edetate disodium, methylparaben, propylparaben, propylene glycol, and sodium hydroxide. Each applicator full of 5 grams of vaginal gel contains approximately 37.5 mg of metronidazole. image-1.jpg
How to use
Metronidazole is sold in more than one form (Topical, Injectable, Solution and Tablet), and each is dosed differently. The instructions below come from the FDA label for application ANDA211786 — follow the label that came with the product you were actually prescribed.
The recommended dose is one applicator full of Metronidazole Vaginal Gel (approximately 5 grams containing approximately 37.5 mg of metronidazole) intravaginally once or twice a day for 5 days. For once a day dosing, Metronidazole Vaginal Gel should be administered at bedtime.
Side effects
Clinical Trials There were no deaths or serious adverse events related to drug therapy in clinical trials involving 800 non-pregnant women who received metronidazole vaginal gel. In a randomized, single-blind clinical trial of 505 non-pregnant women who received metronidazole vaginal gel once or twice a day, 2 patients (one from each regimen) discontinued therapy early due to drug-related adverse events. One patient discontinued drug because of moderate abdominal cramping and loose stools, while the other patient discontinued drug because of mild vaginal burning. These symptoms resolved after discontinuation of drug. Medical events judged to be related, probably related, or possibly related to administration of metronidazole vaginal gel once or twice a day were reported for 195/505 (39%) patients. The incidence of individual adverse reactions were not significantly different between the two regimens. Unless percentages are otherwise stipulated, the incidence of individual adverse reactions listed below was less than 1%: Reproductive: Vaginal discharge (12%), Symptomatic Candida cervicitis/vaginitis (10%), Vulva/vaginal irritative symptoms (9%), Pelvic discomfort (3%). Gastrointestinal: Gastrointestinal discomfort (7%), Nausea and/or vomiting (4%), Unusual taste (2%), Diarrhea/loose stools (1%), Decreased appetite (1%), Abdominal bloating/gas; thirsty, dry mouth. Neurologic:…
Warnings
Important safety information
Convulsive Seizures and Peripheral Neuropathy Convulsive seizures and peripheral neuropathy, the latter characterized mainly by numbness or paresthesia of an extremity, have been reported in patients treated with oral or intravenous metronidazole. The appearance of abnormal neurologic signs demands the prompt discontinuation of metronidazole vaginal gel therapy. Metronidazole vaginal gel should be administered with caution to patients with central nervous system diseases. Psychotic Reactions Psychotic reactions have been reported in alcoholic patients who were using oral metronidazole and disulfiram concurrently. Metronidazole vaginal gel should not be administered to patients who have taken disulfiram within the last two weeks.
Who should not take Metronidazole
Metronidazole Vaginal Gel is contraindicated in patients with a prior history of hypersensitivity to metronidazole, parabens, other ingredients of the formulation, or other nitroimidazole derivatives.
Overdose — what happens if you take too much
There is no human experience with overdosage of metronidazole vaginal gel. Vaginally applied metronidazole gel, 0.75% could be absorbed in sufficient amounts to produce systemic effects. (See WARNINGS. )
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Interactions
Oral metronidazole has been reported to potentiate the anticoagulant effect of warfarin and other coumarin anticoagulants, resulting in a prolongation of prothrombin time. This possible drug interaction should be considered when metronidazole vaginal gel is prescribed for patients on this type of anticoagulant therapy. In patients stabilized on relatively high doses of lithium, short-term oral metronidazole therapy has been associated with elevation of serum lithium levels and, in a few cases, signs of lithium toxicity. Use of cimetidine with oral metronidazole may prolong the half-life and decrease plasma clearance of metronidazole.
Foods & drinks to be careful with
Well-established interactions for this medicine’s drug class, summarized from public health authorities. General information, not medical advice — always confirm with your pharmacist or the label.
Alcohol
Watch out for: beer, wine, spirits, and other products containing alcohol.
Combining alcohol with this antibiotic can cause a disulfiram-like reaction — flushing, nausea, vomiting, headache, and a fast heartbeat.
What to do: Avoid alcohol while taking it and for a few days after your last dose, as your prescriber or the label directs. Alcohol can hide in some liquid medicines and mouthwashes.
Source: Metronidazole — MedlinePlus (U.S. National Library of Medicine)
How long does Metronidazole stay in your body?
The elimination half-life of metronidazole is about 8 hours — the time it takes the body to clear about half of it. As a rule of thumb, a medicine is mostly gone after roughly 4 to 5 half-lives, though this varies from person to person with age and kidney or liver function. This is the average for healthy adults with normal kidney and liver function; the half-life is much longer in newborns (roughly 22 to 109 hours, longer the more premature the baby). Metronidazole has an active metabolite (hydroxy-metronidazole) whose levels build up in older adults (40-80% higher) and in severe kidney disease, though the label does not give a separate half-life for it.
This is general information, not medical advice. It doesn’t tell you when a drug test would read negative (tests detect substances for different, often longer, windows) or when it’s safe to take another dose — ask your pharmacist or prescriber. Source: FLAGYL (metronidazole) label, DailyMed.
Drug class
How this class works, per Metronidazole - StatPearls - NCBI Bookshelf.
May treat (source: NIH RxClass)
- abscess
- amebiasis
- bacteroides infections
- bacterial endocarditis
- pseudomembranous enterocolitis
- giardiasis
See how Metronidazole ranks — best-rated nitroimidazole antimicrobial for:
Dosage forms
Topical, Injectable, Solution and Tablet
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
Ways to save
Ask for the generic
Same active ingredient, far cheaper. Is there a generic? →
Request a 90-day supply
Bulk fills usually lower the per-dose price vs monthly refills.
Use copay cards
Manufacturer copay cards & patient-assistance programs — especially for brand drugs.
Compare alternatives
A same-class option may cost less. See alternatives →
Frequently asked questions
- What does Metronidazole treat?
- Metronidazole (Metronidazole) may be used to treat abscess, amebiasis, bacteroides infections, bacterial endocarditis, pseudomembranous enterocolitis, giardiasis, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- How does Metronidazole work?
- Metronidazole is a nitroimidazole antimicrobial. Nitroimidazole antibiotics (such as metronidazole) are activated inside oxygen-free bacteria and parasites, where they turn into reactive forms that break and destabilize the microbe's DNA. This kills the germ while largely sparing the body's own cells.
- How much does Metronidazole cost?
- Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $0.10 per gm, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins.
- Is there a coupon or discount for Metronidazole?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Metronidazole. To pay less, Metronidazole is already a generic — usually the lowest-cost version — so the main levers are comparing cash prices between pharmacies and using a pharmacy discount-card service. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Metronidazole?
- Metronidazole is marketed by Padagis Israel. You can see Padagis Israel's full profile, rating, and other products on pharmaranks.
- Is Metronidazole a brand-name or generic drug?
- Metronidazole is a generic medication; its active ingredient is Metronidazole. Generics contain the same active ingredient as the brand-name original and are usually lower cost.
- Is Metronidazole available over the counter?
- No. Metronidazole is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Metronidazole come in?
- Metronidazole is currently marketed as topical, injectable, solution and tablet, per the FDA's National Drug Code Directory.
- What class of drug is Metronidazole?
- Metronidazole is classified as nitroimidazole antimicrobial, per the FDA's Established Pharmacologic Class.
- Is Metronidazole FDA-registered?
- Metronidazole is on record with the U.S. FDA under application number ANDA211786. You can verify this on its official FDA label.
- Is Metronidazole safe?
- There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Metronidazole. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
- What are the side effects of Metronidazole?
- Metronidazole's side effects are taken directly from its FDA label. From the label: Clinical Trials There were no deaths or serious adverse events related to drug therapy in clinical trials involving 800 non-pregnant women who received metronidazole vaginal gel. In a randomized,… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
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