Fladystin

Quick links to important sections

Fladystin

Method of action: Antiprotozoal

Treatment option:

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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 Fladystin

Fladystin: Definition and Dual-Action Therapy

Property Description
Active ingredient Metronidazole and Nystatin
Form Vaginal Ovule (Tablet)
Pharmacological class Antimicrobial, Antifungal, and Trichomonacide Combination
Common use Addressing localized infections involving susceptible pathogens and fungi
Origin Synthetic (Metronidazole) and Natural Derivative (Nystatin)

Fladystin is defined as a specialized combination pharmaceutical product delivered as a Vaginal Ovule (or Vaginal Tablet) for targeted local action. Its formulation integrates two distinct, clinically recognized ingredients: Metronidazole (a synthetic nitroimidazole antimicrobial) and Nystatin (a naturally derived polyene antibiotic). This specific dual composition is identified as an Antimicrobial, Antifungal, and Trichomonacide Combination, which distinguishes it from single-agent therapies by providing simultaneous activity against multiple categories of common infective agents.

Composition, Origin, and Specialized Dosage Form

The physical form and route of administration are key to the product's design. The ovule utilizes a neutral base of hard fat, which melts at body temperature, ensuring the focused, high-concentration release of the active ingredients directly at the site of infection. This local administration method is recognized for maximizing therapeutic effect at the target tissue while limiting the amount of medication that is absorbed systemically. Metronidazole is a fully synthetic compound, while Nystatin is a natural antifungal, underscoring the product's specialized combination chemistry.

General Therapeutic Purpose and Dual Action Concept

The core therapeutic purpose of this product is to manage localized infections by leveraging its dual-action capability against both fungal and susceptible bacterial/protozoal components. The presence of Nystatin provides reliable coverage against yeast-like fungi, such as Candida species, while Metronidazole concurrently addresses susceptible anaerobic bacteria and protozoa, including Trichomonas. This combined strategy offers a practical benefit by addressing a broad spectrum of potential causative agents simultaneously, such as those often present in mixed vaginosis.

Regulatory References

  1. FLAGYSTATIN Patient Medication Information

What side effects are possible with Fladystin?

Fladystin: Possible Side Effects and Safety Information

Regulatory documents classify the potential adverse reactions for the Metronidazole/Nystatin combination based on official frequency categories and affected system-organ classes. The most common adverse reactions reported are those related to the local application site, while other effects stem from the systemic absorption of the metronidazole component.

Documented Adverse Reactions and Frequency

Category Description and Classification
Common/Infrequent Local application site effects, including vaginal burning, irritation, itching (pruritus), and a granular sensation. Systemic effects such as a metallic or bitter taste, nausea, and headache are also documented.
Rare/Very Rare Serious systemic effects associated with metronidazole exposure, including severe Central Nervous System (CNS) reactions (e.g., encephalopathy), and Severe Cutaneous Adverse Reactions (SCARs), such as Stevens-Johnson Syndrome (SJS).

Safety Considerations and Restrictions

The occurrence of local irritation and burning is often described in regulatory texts as more pronounced at the beginning of treatment and tending to diminish over the course of therapy. Official labeling mandates a strict safety restriction regarding alcohol consumption: patients must avoid alcoholic beverages during treatment and for at least one day afterward, due to the risk of a Disulfiram-like reaction (e.g., flushing, vomiting) caused by systemic metronidazole absorption.

Regulatory authorities also define specific population constraints. The combination should be used with caution in individuals with severe hepatic impairment due to potential reduced clearance of metronidazole. Furthermore, official documents advise avoidance during the first trimester of pregnancy and during the period of breast-feeding.

Overdose and Emergency Response

Overdose and When to Seek Help

Official regulatory documents emphasize that in the event of an overdose, contact with a healthcare professional, hospital emergency department, or a Poison Control Center must occur immediately, even if the patient exhibits no apparent signs or symptoms of illness.

Potential Overdose Risks

While specific overdose data for this combined product are limited, the overdose profile is structured around the risks associated with its systemically absorbed component, metronidazole. Overdose with systemic metronidazole has been documented in regulatory reports to carry the potential for serious outcomes, including:

  • Severe Liver Failure: Cases of serious liver failure, including those resulting in death, have been reported following the overdose of systemically-active metronidazole.
  • Serious Central Nervous System (CNS) Issues: Overdose may also affect the nervous system, with documented clinical manifestations that include seizures and encephalopathy.

Condition-Specific Overdose Note

Individuals diagnosed with Cockayne syndrome have been noted in regulatory warnings as a specific population susceptible to severe liver failure, including fatal outcomes, when treated with metronidazole. Due to this risk, liver function should be strictly monitored in these patients during and after any exposure to the drug.

Required Emergency Action

Because the most severe risks, such as liver failure, may not present symptoms right away, immediate medical consultation is required to assess the potential toxicity and determine the need for supportive treatment, regardless of how the person currently feels.

Therapeutic Uses of Fladystin

What Fladystin Treats: Main Uses and Benefits

Fladystin is commonly used in clinical situations where there is evidence of co-infection, specifically targeting both protozoal agents, such as Trichomonas vaginalis, and yeast-like fungi, primarily Candida albicans. This combination is relevant for conditions presenting with symptomatic overlap and is considered relevant for addressing the multiple components of infectious vaginitis. The combination generally assists with managing conditions involving acute or disruptive symptom patterns.

This medication may assist with managing the acute and distressing symptom cluster of infectious vaginitis, which includes intense itching, burning sensations, irritation, abnormal discharge, and associated odor. Used for managing symptoms, this medication provides supportive relief that may help patients cope more steadily with difficult episodes and supports general well-being.

“This therapeutic approach is relevant when supportive symptom management is appropriate, particularly for the difficult symptoms of acute infectious episodes.”

The therapeutic benefit helps manage symptoms, which may assist with managing abnormal, pathological discharge and associated unpleasant odor. This action supports improved day-to-day comfort and stability during periods of heightened infectious symptoms. It is relevant for managing symptom clusters that interfere with daily comfort and create noticeable physiological strain.


Quick Fact: Relief for Local Discomfort and Itching

This medication is primarily applied in settings where additional management of discomfort is required due to the simultaneous activity of fungal and protozoal pathogens, helping to ease the overall symptom load.

Eligibility and Restrictions for Use

Official Eligibility Profile: Who Can and Cannot Use Fladystin

This section summarizes the official eligibility status for Fladystin as documented in regulatory government labeling (e.g., FDA, EMA, Health Canada). The profile is based on required sections detailing absolute contraindications, age limits, and physiological status.

Eligibility Scope

Classification Official Regulatory Status
Populations for whom use is contraindicated Contraindicated for individuals with known hypersensitivity to the active ingredients (Metronidazole, Nystatin) or any component of the formulation.
Populations for whom use is restricted Use is subject to a physician’s determination where the potential benefits are judged to outweigh the possible hazards in certain clinical situations.

Specific Eligibility Rules

  • Age-related eligibility rules: Safety and effectiveness have not been established for the pediatric population (under 18 years of age); therefore, use is typically not authorized by some regulatory bodies for this group. Similar official data limitations often exist for the geriatric population.
  • Pregnancy and lactation eligibility: Use is generally not recommended during the first trimester of pregnancy. For the remaining period and during breastfeeding, use is to be avoided unless the therapeutic benefits clearly outweigh the potential risks to the fetus or infant.
  • Condition-specific eligibility rules: Use may be prohibited or restricted for patients with a history of active neurological disorders or blood dyscrasia, unless the patient's condition is carefully managed by a physician.

Resulting Eligibility Structure

Official regulatory documents define eligibility by stating absolute prohibitions (contraindications) and detailing populations that require specific caution or for whom safety data are not established. The primary exclusion for Fladystin is hypersensitivity to its ingredients, while age and reproductive status are documented as requiring limited or restricted use based on regulatory review of available clinical data.

What should I know about interactions with other medicines?

The official regulatory interaction profile for Fladystin, a combination product containing Metronidazole and Nystatin, is primarily determined by the systemic potential and known interactions of the Metronidazole component. The official label requires specific constraints regarding concurrent substances and products.

Interaction Classification and Constraints

Category Regulatory Statement Basis
Pharmacodynamic/Metabolic Restriction Abstinence from Alcohol (Ethanol) is required during therapy and for at least one to three days after treatment completion due to the potential for an officially documented adverse reaction (disulfiram-like effect).
Exposure Modification Co-administration with Coumarin Anticoagulants (e.g., Warfarin) is officially noted to potentiate the anticoagulant effect, requiring careful clinical monitoring of INR/prothrombin time.
High-Risk Combinations Disulfiram should not be given to patients who have taken Metronidazole within the prior two weeks due to the reported risk of psychotic reactions.
Product Compatibility The vaginal dosage form may officially decrease the effectiveness of latex-containing contraceptives, necessitating the use of alternative barrier methods.

Co-administration with other medicines that are known to significantly prolong the QTc interval requires cautionary consideration in the official labeling. Similarly, drugs that alter Metronidazole's metabolism, such as Lithium, necessitate official monitoring for increased systemic exposure.

Mechanism of Action

Reductive Activation and Genetic Disruption of Anaerobes

This domain covers the mechanism of Metronidazole, which acts as a prodrug selectively activated by specific enzymes and low-oxygen conditions unique to anaerobic bacteria and protozoa. Upon activation, it forms toxic radical intermediates that cause irreversible damage to the pathogen's DNA structure, blocking its ability to replicate and leading to the loss of cell viability in these susceptible organisms at the local site.

Ergosterol Binding and Fungal Membrane Collapse

This domain explains the action of Nystatin, a polyene agent that specifically binds to ergosterol, a sterol essential for the structural integrity of the fungal cell membrane. This binding rapidly leads to the formation of pores or channels, causing the immediate and uncontrolled leakage of essential intracellular ions like potassium (K^+), thereby disrupting the cell’s osmotic balance and causing the physical destabilization and death of the fungus.

Functional Complementarity for Comprehensive Elimination

The drug's overall effect arises from its dual-action cascade, where Metronidazole and Nystatin engage two completely independent and non-overlapping mechanisms targeting different pathogen categories (anaerobes/protozoa vs. fungi). This concurrent deployment of distinct molecular damage pathways contributes to the simultaneous elimination of both bacterial/protozoal and fungal pathogen populations at the local application site.

Dosage and Administration Information

Fladystin is administered solely through the intravaginal route using a specialized ovule, or vaginal tablet. The ovule formulation combines 500 mg of Metronidazole and 100,000 IU of Nystatin, designed for local delivery at the required site.

The standardized adult usage pattern involves the insertion of one ovule once daily, typically for a continuous course of 10 consecutive days. This medication is specifically timed for administration at bedtime to maximize the amount of time the medication remains in place.

Proper use requires a specific administration step: the vaginal ovule should be briefly moistened with water immediately prior to insertion to facilitate dissolution once inside the body. It must then be inserted deep into the vagina using the provided applicator.

Certain procedural constraints apply to this treatment. To ensure the full course is completed correctly, instructions define that treatment must not be interrupted during menstruation. Furthermore, for the full 10-day period, patients must abstain from sexual intercourse and avoid the concurrent use of other intravaginal products, such as douches or tampons. If the initial course is insufficient, the protocol allows for the administration of a second 10-day course.

For specific patient populations, it is noted that dose reduction may be required for individuals with severe hepatic impairment. Separately, the use of the applicator is generally not recommended after the seventh month of pregnancy.

Recent Clinical Evidence

Research Overview: Understanding Fladystin Studies

This section summarizes the type of research that has been conducted on the combination ovule, including the study designs used in research exploring the condition and the specific outcomes that researchers were evaluating. Research on this product mainly explores its potential role in managing infections that are associated with both protozoal and fungal components simultaneously. The available evidence includes established trial designs, but much of the data is derived from older studies and comparative trials, meaning large-scale studies against a placebo are limited.

Evidence for Use in Mixed Trichomonas and Candida Infections

Researchers examined the combination ovule in short-term randomized studies and comparative trials, primarily involving women who had symptoms of infection. These studies generally focused on two types of outcomes: outcomes related to physical discomfort, which includes patient reports of changes in itching, burning, and abnormal discharge; and microbiological outcomes, which tracked the measured elimination or persistence of Trichomonas vaginalis and Candida albicans organisms after the observed time intervals.

In these research scenarios, the findings describe patterns observed in the studies regarding both the reported symptom changes and the microbiological outcomes. It is important to remember that research provides context but not individual predictions regarding personal outcomes.

Durability of Outcomes and Long-Term Follow-up

The primary research for the ovule was observed in research exploring short-term symptom changes, with initial follow-up often scheduled days to a few weeks after the treatment period ended. Some comparative trials have also monitored recurrence rates over an intermediate duration, with some women being followed for up to 104 days. However, data for long-term outcomes are limited regarding the durability of the reported changes beyond these intermediate monitoring periods. Evidence is limited concerning the persistence of outcomes (such as the absence of infection) six months or one year after treatment.

Limitations and Gaps in Fladystin Research

A key limitation is that many existing studies are comparative, meaning they explore how the ovule performed alongside another active treatment rather than against a neutral placebo. This means that research specifically exploring the combination ovule for the mixed condition is often limited. Furthermore, evidence quality varies across studies, and the follow-up durations were limited in many cases, meaning data for the long-term patterns of infection return are limited. Sample sizes were modest in some of the original investigations, contributing to the idea that data are still emerging for certain outcomes.

Key Studies & References

  1. Metronidazole Use for Susceptible Anaerobic Bacteria and Protozoa (General PubMed Context)
  2. Nystatin Use for Yeast-like Fungi and Candida Species (General PubMed Context)
  3. Systematic Review Context for Metronidazole/Nystatin Combination Therapy in Mixed Vaginosis (General PubMed Context)

Frequently Asked Questions (FAQ)

Common questions about Fladystin (FAQ)

Q: What is the main condition or use that Fladystin is approved to treat?

According to the official product information, Fladystin is indicated for the treatment of mixed vaginal infections. This involves managing infections caused by susceptible pathogens, specifically including Trichomonas vaginalis and Candida albicans (candidiasis).

Q: How does Fladystin differ from other common medications in its class?

Fladystin is described as a combination pharmaceutical product because it integrates two distinct active ingredients, Metronidazole and Nystatin. This dual composition is intended to provide simultaneous activity against both protozoal/bacterial and fungal pathogens, distinguishing it from single-agent therapies.

Q: Does Fladystin only address symptoms, or is it described as targeting the underlying cause?

The mechanism of action is described as targeting the underlying cause by chemically disrupting the DNA and cell structure of the pathogens, which leads to their elimination. Research studies track both this microbiological elimination and patient-reported changes in symptoms like itching and discharge.

Q: How long can a person expect common side effects from Fladystin to last?

Regulatory documents often note that local side effects, such as irritation or burning at the application site, are often more pronounced at the beginning of treatment. These effects generally tend to diminish over the course of the therapy. The expected duration for systemic effects like a metallic taste is not commonly specified.

Q: Are there any reported differences in side effects between Fladystin and a placebo group in clinical studies?

Research summaries indicate that large-scale studies directly comparing this combination product to a neutral placebo are limited, as much of the evidence is derived from comparative trials against other active treatments. Specific, comparative side effect rates versus placebo are not commonly summarized for the public.

Q: Are there documented cases of Fladystin failing to work in clinical trials?

The official labeling addresses the possibility that the initial course may not achieve a cure. The product monongraph defines a clinical protocol allowing for the administration of a second 10-day course if a microbiological cure is not achieved after the initial treatment period.

Q: What is the highest dosage strength of Fladystin that has been studied in research?

The standard dosage strength of the ovule formulation is 500 mg Metronidazole and 100,000 IU Nystatin. Information regarding whether different or higher dosage strengths have been formally studied in the research overview is not generally detailed in the public label.

Q: How is the evidence for Fladystin's effectiveness described by regulatory bodies?

Regulatory bodies approve the medication for its indicated use based on evidence from clinical studies. This evidence shows that the combined action effectively eliminates the target pathogens and results in improvement in clinical symptoms.

Q: What patient counseling information is emphasized in regulatory materials for Fladystin?

Official regulatory documents emphasize several critical counseling points. These include strict abstinence from alcohol during and immediately after therapy, avoiding sexual intercourse during treatment, and avoiding concurrent use of other intravaginal products or devices.

Q: Are there specific over-the-counter medications that have known interactions with Fladystin?

The Metronidazole component has known interactions, such as potentiating the effects of certain anticoagulants. Because of the potential for unexpected effects, the product information notes that discussion with a healthcare professional may be necessary when considering the safety of taking specific over-the-counter medications.

Q: What are the known interactions between Fladystin and common herbal or vitamin supplements?

Regulatory sources generally note that there is insufficient information available to state that complementary medicines, herbal remedies, and nutritional supplements are safe to take with prescription drugs. They are not typically tested for drug-drug interactions with this product.

Q: How is the potential interaction of Fladystin with common blood pressure medications described?

The official label requires cautionary consideration with co-administration of medicines known to significantly prolong the QTc interval (a measure of heart rhythm). This caution applies to some classes of blood pressure medications, though specific classes are not generally named in patient information.

Q: What is the procedure for handling a missed dose of Fladystin, based on official instructions?

The official label describes the general procedure for a missed dose: if a dose is forgotten, it is usually advised to use it as soon as possible, but to skip the dose if it is almost time for the next. The label also contains a specific warning never to use a double dose to make up for a missed one.

Q: Does Fladystin cause drowsiness that could affect daily activities?

The product information indicates that this medication may cause dizziness, confusion, or vertigo as a side effect. The product information notes the importance of exercising caution when performing tasks that require alertness if the medication causes these effects.

Q: Does Fladystin interact with common anti-anxiety or antidepressant medications?

Caution is required when Fladystin is used concurrently with certain psychoactive medications, such as Lithium, and those that can significantly prolong the QTc interval. The label suggests that a discussion with a healthcare professional is important before combining this product with any anti-anxiety or antidepressant drug.

Q: How does Fladystin affect a person’s ability to operate machinery?

The regulatory documents state that tasks requiring high concentration, such as driving or operating heavy machinery, should be avoided if a person experiences adverse reactions like confusion, dizziness, vertigo, or vision problems.

Q: Are there any reports of Fladystin causing changes to sleep patterns?

Trouble sleeping, known as insomnia, is listed as a possible side effect associated with the Metronidazole component of this medication.

Q: Does Fladystin have a Boxed Warning or any similar critical safety alert?

Regulatory labeling includes critical safety alerts regarding the use of the Metronidazole component. These include serious warnings about the risk of severe liver failure in patients with Cockayne syndrome and the potential for severe cutaneous adverse reactions (SCARs).

Q: Has Fladystin been studied in patients with cardiovascular conditions?

Post-market surveillance has identified reports of QT prolongation, particularly when Metronidazole was administered with drugs that affect the QT interval. The label notes that caution is required, indicating potential concern for patients with existing heart conditions.

How should Fladystin be stored and disposed of?

How to Store and Dispose of Fladystin

Official regulatory guidelines define specific conditions for the storage and disposal of Fladystin Vaginal Ovules to maintain product stability and integrity.

Storage Requirements

The medication must be stored at a controlled room temperature, typically between 15 - 25 C, and protected from freezing, excess heat, moisture, and direct light. The ovules must remain in their original container, which should be kept tightly closed. As a mandated safety requirement, Fladystin must be stored out of the sight and reach of children.

Storage Constraint Required Action
Temperature Store between 15 - 25 C; do not freeze.
Protection Keep away from heat, moisture, and direct light.
Container Store in the original, tightly closed container.

Disposal Instructions

Unused or expired Fladystin should not be disposed of in household trash or poured into wastewater (e.g., down a sink or toilet). Official instructions require consultation with a pharmacist or local waste management authority for proper pharmaceutical return and disposal procedures.

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

Available in countries:

Equivalent of Fladystin found in:

A-Z Index: