Flazol

Quick links to important sections

Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Flazol

Property Description
Active Ingredient Metronidazole
Pharmacological Class Antimicrobial Agent (Nitroimidazole)
Form Tablet, Suspension, Intravenous Solution, Topical Cream/Gel
Primary Action Type Antibiotic and Antiprotozoal
Origin Synthetic Compound

Flazol is a prescription-only synthetic pharmaceutical preparation whose active substance is Metronidazole. Its core identity is defined by its membership in the nitroimidazole class of antimicrobials, functioning distinctly as both a targeted antibiotic and an effective antiprotozoal agent.

What Type of Medicine is Flazol and What is its Classification?

Flazol is classified as a dual-action antimicrobial, specifically a synthetic organic compound designed to target two distinct types of pathogens: obligate anaerobic bacteria and certain protozoal parasites. The active ingredient, Metronidazole, is a synthetic derivative that exhibits selective toxicity by becoming chemically activated inside the susceptible microbes themselves, a mechanism critical to its efficacy. Metronidazole is recognized as a primary agent against certain protozoal diseases, used in the treatment of parasitic infections. This application highlights the drug's ability to eliminate these specific parasitic targets.

Composition, Origin, and Available Forms

The primary component of Flazol is the chemical entity Metronidazole, a compound originating from the synthetic nitroimidazole structure. This medicine is provided in multiple pharmaceutical preparations to facilitate different routes of administration. These forms include systemic options such as oral tablets and oral suspension, as well as an intravenous (IV) solution for parenteral administration in severe cases. A distinctive feature of the Flazol formulation family is the provision of an oral suspension, often used for pediatric or non-swallowing adult patient groups. Furthermore, localized treatments are supplied as topical creams or gels, utilizing an appropriate base or vehicle for direct application.

The General Therapeutic Purpose of Flazol

The general therapeutic purpose of Flazol is the eradication of infection caused by microorganisms that are susceptible to the nitroimidazole mechanism. Flazol's highly focused action is beneficial for managing conditions traced to obligate anaerobic bacteria and specific protozoal parasites. For instance, it is commonly used for prophylaxis against postoperative infections, demonstrating its role beyond treating active disease. By disrupting the nucleic acid synthesis of these pathogens, Flazol helps eliminate the microbial source of the infection, which is its overall function in therapeutic management.

Regulatory References

  1. Metronidazole: MedlinePlus Drug Information

What side effects are possible with Flazol?

Possible Side Effects and Safety Information

The following safety information and adverse reactions for Flazol (Metronidazole) are based exclusively on official government regulatory documents.

Adverse Reactions and Frequency

Adverse reactions are classified by frequency and the body system affected, according to regulatory standards.

Classification Examples of Reactions (by SOC)
Common Nausea, Vomiting, Diarrhea, Abdominal Cramping, Unpleasant Metallic Taste, Headache
Less Common/Rare Peripheral Neuropathy, Convulsive Seizures, Encephalopathy, Aseptic Meningitis, Pancreatitis

Serious adverse reactions documented in regulatory sources include central nervous system toxicities (such as seizures and encephalopathy), severe cutaneous adverse reactions (SCARs), and severe liver toxicity, particularly in patients with Cockayne Syndrome.

Key Regulatory Safety Restrictions

Official labeling mandates specific safety restrictions to avoid severe complications:

  • Alcohol Restriction: Consumption of alcohol or products containing propylene glycol is strictly forbidden during therapy and for at least three days after the last dose due to the risk of a severe Disulfiram-like reaction (e.g., flushing, severe vomiting, headache).
  • Carcinogenicity Warning: Regulatory documents include a Boxed Warning that metronidazole has shown potential carcinogenicity in animal studies, advising against unnecessary or prolonged use.
  • Use in Impaired Function: Monitoring for adverse events is specifically required for patients with severe hepatic impairment or end-stage renal disease (ESRD).

Population-Specific Notes

Specific cautions apply to certain groups. For instance, the use of Flazol is contraindicated in individuals with Cockayne Syndrome due to the risk of fatal liver failure. Additionally, caution and monitoring are advised for geriatric patients and those with a history of blood dyscrasia.

Overdose and Emergency Response

Acute overdose with Flazol (metronidazole) has been documented in cases of accidental or intentional ingestion, with reports citing massive single oral doses. Immediate medical attention must be sought if an overdose is suspected or occurs.

Overdose is primarily characterized by clinical manifestations affecting the gastrointestinal system and the central nervous system (CNS). Documented presentations include nausea, vomiting, ataxia (loss of muscle coordination or balance), and disorientation. High-dose or prolonged exposure is associated with the risk of serious neurological events, including convulsive seizures and the development of peripheral neuropathy. Any appearance of abnormal neurological signs, such as numbness, tingling, or seizures, requires immediate cessation of the medicine and prompt reporting to a healthcare provider.

If the individual collapses, has trouble breathing, experiences a seizure, or cannot be awakened, emergency services must be contacted immediately.

The officially documented management framework states that there is no specific antidote known for metronidazole overdose. Therefore, treatment consists exclusively of symptomatic and supportive therapy. Furthermore, patients with severe hepatic impairment may experience significant drug accumulation due to impaired clearance, which can contribute to toxicity and must be considered during medical evaluation.

Therapeutic Uses of Flazol

What Flazol Treats: Main Uses and Benefits

Flazol is commonly used across therapeutic domains where additional symptomatic support is needed due to infections caused by specific susceptible organisms, namely obligate anaerobic bacteria and protozoal parasites. The medication is used for managing symptoms related to systemic imbalance in conditions characterized by periods of heightened symptoms, such as specific intra-abdominal, gynecologic, and bloodstream infections. The primary therapeutic purpose is relevant for easing symptoms that create noticeable physiological strain associated with deep-seated illness and inflammation.

It plays a role in managing conditions presenting with acute or disruptive episodes of systemic discomfort, including specific serious bacterial and parasitic infections. Flazol generally supports patients during difficult episodes by easing distress and may assist with maintaining functional stability.

In addition to treating active disease, Flazol is applied as prophylaxis to prevent anaerobic infection following certain surgical procedures. Furthermore, it supports the patient during recurrent episodes by treating asymptomatic partners in cases like trichomoniasis, and may assist with managing the cycle of reinfection, contributing to improved comfort.


Quick Fact: Relief for Symptoms related to physical discomfort


Regulatory References

  1. Metronidazole: MedlinePlus Drug Information

Eligibility and Restrictions for Use

Flazol is generally used to treat anaerobic bacterial infections and protozoal infections such as trichomoniasis and amebiasis. However, it is not suitable for everyone, and your healthcare provider must carefully evaluate your medical history before prescribing it.


Who Cannot Use Flazol?

Flazol is contraindicated and should not be used by patients with:

  • A known allergy or hypersensitivity to Flazol (metronidazole) or any other nitroimidazole drug (like tinidazole).
  • Cockayne Syndrome (a rare genetic disorder), due to the risk of severe, potentially fatal liver failure.
  • Patients who have consumed alcohol or products containing propylene glycol during treatment and for at least three days after the last dose, due to a severe, disulfiram-like reaction (flushing, nausea, vomiting, rapid heart rate).
  • Patients who have taken disulfiram (a medication for alcoholism) within the last 14 days, as this combination can cause psychotic reactions.

Use With Caution

Tell your doctor if you have a history of or currently experience any of the following conditions, as Flazol should be used with caution and may require a dosage adjustment or closer monitoring:

Condition Why Caution is Needed
Pregnancy Generally avoided during the first trimester; benefit must outweigh the risk during later stages.
Breastfeeding Excreted into breast milk; may require a temporary interruption of breastfeeding.
Severe Liver or Kidney Disease The drug can accumulate in the body, requiring a dose reduction, especially in severe hepatic impairment.
Blood Disorders History of blood dyscrasias, such as a low white blood cell count (leukopenia).
Central Nervous System (CNS) Disorders History of seizures, neurological problems, or confusion; Flazol may aggravate these conditions.

What should I know about interactions with other medicines?

Flazol, which belongs to the nitroimidazole class of antimicrobial agents, has several documented interactions with other medicines and products. Awareness of these combinations is essential to avoid potentially serious adverse reactions.

Contraindicated Combinations

Interacting Product Potential Result Mandatory Restriction
Alcohol (Ethanol) & Propylene Glycol Severe disulfiram-like reaction (flushing, vomiting, abdominal cramps, headaches). Avoid all alcohol/propylene glycol-containing products during therapy and for at least three days after the final dose.
Disulfiram Psychotic reactions and confusion, especially in patients with a history of alcohol use. Do not administer Flazol if disulfiram has been taken within the last two weeks.

Clinically Significant Interactions

Flazol has the potential to enhance the effects of certain medications. Concurrent use requires careful monitoring by a healthcare professional.

  • Warfarin and other Oral Anticoagulants: Flazol may intensify the blood-thinning effects of these medicines, leading to a prolonged prothrombin time and increased risk of bleeding. The dosage of the anticoagulant may require adjustment.
  • Lithium: Flazol may increase serum lithium concentrations, which can result in toxicity. Frequent monitoring of lithium and kidney function is necessary.
  • Busulfan: Plasma concentrations of busulfan may increase, raising the risk of severe toxicity. Concomitant use should be avoided unless the benefits outweigh the risks.
  • Enzyme Inhibitors (e.g., Cimetidine): These may reduce the metabolism of Flazol, potentially leading to increased blood levels of Flazol and an elevated risk of side effects.

Mechanism of Action

Selective Activation and Microbial DNA Damage

The mechanism of Flazol, featuring the active ingredient Metronidazole, operates through a unique, targeted activation resulting in the cytotoxicity of susceptible pathogens and the modulation of local immune cell function. Metronidazole functions as an inactive prodrug that must enter the microbe to be chemically reduced. This reduction is catalyzed by nitroreductase enzymes and low-redox potential proteins (like Ferredoxin) found exclusively within obligate anaerobic bacteria and certain protozoal parasites. The resulting, highly reactive nitro radical anion intermediate immediately fragments and disrupts the microbe’s DNA, leading to irreversible cellular damage.

Constraint-Dependent Efficacy and Local Modulation

The cytotoxic mechanism is strictly constrained by the anaerobic environment; high oxygen tension re-oxidizes the radical intermediate back to the inactive prodrug (redox cycling). Independent of this primary action, the drug also modulates human inflammatory pathways by inhibiting the motility of neutrophils and reducing the generation of reactive oxygen species. This secondary effect reduces local oxidative stress and contributes to the modulation of the tissue response.

Dosage and Administration Information

How to Use Flazol: Official Administration Guidelines

Flazol (Metronidazole) usage is defined by specific administration routes, standardized dose calculations, and precise delivery conditions. The medicine is administered by three main routes, depending on the therapeutic need.


Administration Scope

Property Instruction / Rule
Route of Administration Oral (tablet/suspension), Intravenous (IV) Infusion, and Topical (cream/gel).
Dosing Schedule Systemic use involves a 15 mg/kg loading dose for IV administration followed by maintenance doses of 7.5 mg/kg. Oral doses typically range from 250 mg to 750 mg per administration.
Frequency Systemic administration generally occurs every 6 or 8 hours (Q6H or Q8H).
Timing in relation to meals Oral tablets are directed to be taken with or immediately after food to mitigate gastrointestinal discomfort.

Procedural and Population Rules

Property Instruction / Rule
Preparation IV solutions must be infused slowly over a period of 30 to 60 minutes.
Age-Group Rules Pediatric dosing is calculated based on body weight. Older adults typically follow standard adult regimens.
Duration The standard course for most systemic infections typically lasts 7 to 10 days, and should not generally exceed this duration.
Adjustment Rule A specific 50% dose reduction is recommended for patients with severe hepatic impairment (liver dysfunction).

The administration protocol mandates the use of specific formulations and routes to ensure appropriate exposure. This structured approach governs the dose calculations, defines the necessary timing, and includes specific practical steps, establishing the standardized protocol for administration.

Recent Clinical Evidence

Research evidence / Overview of Studies for Flazol


Evidence for Use in Anaerobic Bacterial and Surgical Prophylaxis Studies

Flazol has been studied in research exploring the treatment of infections caused by anaerobic bacteria, such as those that can affect the abdomen or pelvis. The core evidence in this area comes from short-term Randomized Controlled Trials (RCTs) and comprehensive systematic reviews. These research efforts primarily monitored clinical outcomes related to systemic or functional imbalance, such as tracking changes in white blood cell counts and body temperature to see how symptoms evolved in the observed populations. Studies frequently evaluate Flazol as a component in regimens designed to cover mixed microbial populations.

Research has also explored Flazol's role in preventing infection following high-risk procedures like colorectal surgery, known as surgical prophylaxis. Data exploring Flazol's effect when used as a single agent for this preventative purpose remain limited.


Evidence for Use in Protozoal and Parasitic Infections

Research has also explored Flazol's role in conditions caused by certain protozoal parasites, including Trichomoniasis, Amebiasis, and Giardiasis. For these conditions, RCTs was studied for and comparative trials was evaluated in, primarily focusing on parasitological measures and patient-reported outcomes.

For Trichomoniasis, studies reported patterns related to parasitological measures following various regimens. Research acknowledges scientific reports describing the emergence of parasite strains that appear to have reduced susceptibility to this class of medication.

In the case of Amebiasis, Flazol was evaluated in patients with both intestinal infection and extra-intestinal forms like liver abscesses. This means that long-term effects are not fully established for Flazol alone, as follow-up often involves secondary medication intended to address chronic infection.


Evidence Consistency and Research Gaps

Overall, the research base for Flazol is extensive for treating specific infections, relying on many RCTs. However, findings describe group patterns, and several areas remain uncertain. The lack of long-term evidence in many areas means its role in managing conditions characterized by fluctuating or episodic manifestations over many months is not fully established. Research involving specific groups like children or pregnant patients often focuses on specific time periods or patient characteristics.

Key Studies & References

  1. Metronidazole - StatPearls (Overview of Indications and Dosing Regimens)
  2. Controlling wound odor with metronidazole: a systematic review (Includes early comparative/case studies and review methodology)

Frequently Asked Questions (FAQ)

Common questions about Flazol (FAQ)

Q: What is Flazol?

A: Flazol is a prescription medicine that contains two active components: Ofloxacin and Ornidazole. It is a combination antibiotic used to treat a variety of bacterial and parasitic infections. Ofloxacin works by preventing the division and repair of bacterial cells, leading to their death. Ornidazole kills parasites and anaerobic bacteria by damaging their DNA.

Q: Is Flazol safe to use?

A: Flazol is safe for most patients when taken as prescribed by a healthcare provider. Like all medications, it can cause side effects. Common side effects may include nausea, vomiting, stomach pain, dizziness, headache, dryness in the mouth, and heartburn. If you experience any persistent problems or increased severity of symptoms while taking this medication, you should consult your doctor.

Q: What should I avoid while taking Flazol?

A: You should not consume alcohol while taking Flazol. The combination may lead to excessive drowsiness and could irritate your stomach. In some cases, consuming alcohol with similar medicines can cause an unpleasant reaction (a disulfiram-like reaction) with symptoms such as flushing, headache, nausea, and vomiting. You should also use caution with activities requiring mental focus such as driving, as Flazol may cause dizziness and sleepiness. Wait until you know how the medicine affects you before engaging in such activities.

Q: Are there any specific warnings or contraindications for Flazol?

A: Flazol should not be used by patients with a known allergy to Ofloxacin, Ornidazole, or any medicine belonging to the quinolone (like Ofloxacin) or nitroimidazole (like Ornidazole) group of antimicrobial agents. Patients with severe kidney or liver disease should use Flazol with caution, as a dose adjustment may be needed. You must inform your doctor about any pre-existing conditions.

Q: What if I miss a dose of Flazol?

A: If you miss a dose, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose and continue with your regular schedule. Do not take a double dose to make up for a missed one. Consult your doctor if you are unsure.

Q: Can I stop taking Flazol when I start feeling better?

A: No, you must complete the full course of treatment as prescribed by your doctor, even if your symptoms improve sooner. Stopping the medication too early can lead to the infection coming back and may result in the bacteria or parasites becoming resistant to the antibiotic.

How should Flazol be stored and disposed of?

Flazol (Metronidazole) must be stored and handled according to specific regulatory conditions to ensure stability and potency:

Requirement Official Statement
Storage Temperature Store at controlled room temperature, typically 15 C to 25 C (59 F to 77 F).
Environmental Protection Protect the medicine from light and moisture; store in the original, tightly closed container.
Prohibited Handling Do not refrigerate and do not freeze the product.
Child Safety Keep this medicine and all containers out of the reach of children.
Disposal Guidelines Dispose of expired or unused medicine properly, ideally through a drug take-back program. Do not flush down the toilet or place in household trash unless specifically instructed by the labeling or the FDA/EPA, to prevent environmental contamination.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

Available in countries:

Equivalent of Flazol found in:

A-Z Index: