Secnil

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Secnil

Method of action: Antiprotozoal

Treatment option:

Medically reviewed

Marina Burgos

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 Secnil

Quick Facts

Property Description
Active Ingredient Secnidazole (INN)
Forms Oral tablets, Granular powder for oral suspension
Pharmacological Class Anti-infective agent, Antiprotozoal drug
Common Use Eliminating specific infectious microbes (protozoa and bacteria)
Origin Synthetic compound (Third-generation nitroimidazole)

Secnidazole: Identity and Classification

Secnil is a medicinal preparation containing the active ingredient Secnidazole, a synthetic compound classified as a 5-nitroimidazole derivative. This classification places it within a specialized group of anti-infective agents designed for systemic action against targeted pathogens. It is typically supplied as a single-ingredient product for the oral route of administration.

Secnidazole is categorized as an antiprotozoal agent used for amoebiasis and other protozoal diseases. This categorization reflects its recognized role in fighting certain parasitic infections, a role supported by its pharmacological properties.

Specialized Action and Purpose

Secnidazole is specifically an Antiprotozoal drug and an anti-anaerobic agent. Its primary purpose is to eliminate susceptible protozoa and obligate anaerobic bacterial species from the body. The drug is often noted for its favorable pharmacokinetic profile, which facilitates its use as a highly convenient preparation, a key differentiating factor from older nitroimidazoles.

Its mechanism relies on selective toxicity: it is activated only by specific enzymes found within these target pathogens, which transforms the drug into a highly reactive substance that damages the microbes’ DNA. This compound is effective against susceptible anaerobic organisms, highlighting its focused benefit as an antimicrobial that targets specific microbial causes of infection.

Regulatory References

  1. NLM (NIH) LiverTox Secnidazole Summary
  2. MedlinePlus Secnidazole Drug Information

What side effects are possible with Secnil?

Possible Side Effects and Safety Information

The safety profile for Secnil (Secnidazole) is established by regulatory documents that classify potential adverse reactions based on frequency and affected system-organ classes.

Adverse Reaction Classification

Most documented side effects are classified as Common, meaning they are reported in 1% to 10% of patients during clinical study. These reactions primarily involve the Gastrointestinal and Nervous Systems.

System Organ Class Common Adverse Reactions (Examples)
Gastrointestinal Disorders Nausea, vomiting, abdominal pain, diarrhea, dysgeusia (metallic taste)
Nervous System Disorders Headache, dizziness
Infections and Infestations Vulvovaginal candidiasis

Serious Adverse Reactions and Safety Constraints

The official safety information includes reports of more serious adverse reactions derived from postmarketing surveillance, though these appear to be rare. These include potential for peripheral neuropathy and severe hypersensitivity reactions such as angioedema.

Secnidazole is a nitroimidazole derivative, and the official label includes warnings related to the entire drug class, noting high-level concerns regarding potential blood dyscrasias and carcinogenicity observed in long-term animal studies with related medicines.

High-level safety constraints include the mandatory precaution that alcohol ingestion must be avoided during treatment due to the potential for a disulfiram-like reaction.

Population-Specific Safety Notes

The regulatory profile sets limitations for specific patient groups:

  • Pregnancy and Lactation: Use during pregnancy is constrained to situations where it is clearly necessary, and specific precautions must be taken concerning continued use while breastfeeding.
  • Pediatric Use: Safety and effectiveness have not been established in patients younger than 12 years of age.

Overdose and Emergency Response

Official Regulatory Status on Overdose

The official regulatory documentation for Secnidazole (Secnil) generally does not describe a unique set of clinical manifestations or symptoms that are specific to an acute overdose scenario. In the absence of a documented toxidrome, regulatory guidance emphasizes required emergency procedures and general supportive care.

The prescribing information confirms that no specific antidote is known for Secnidazole intoxication. Therefore, the official course of action for managing overdose is restricted to providing symptomatic and supportive treatment. This includes monitoring the patient’s clinical status and managing symptoms as they arise. No specific dose-related factors or population-specific risks (e.g., for elderly or pediatric patients) are noted within the official overdose sections.

When to Seek Urgent Medical Help

Authorities mandate immediate contact with emergency services when severe signs of intoxication occur. Urgent medical attention is required for any suspected overdose event. Specifically, you must call emergency services (such as 911) immediately if the individual has collapsed, had a seizure, has trouble breathing, or cannot be awakened. Additionally, the official guidance directs contacting the Poison Control helpline (1-800-222-1222) for information regarding the specific exposure.

Therapeutic Uses of Secnil

Secnil, which contains the active ingredient secnidazole, is a nitroimidazole antimicrobial agent that is applied in addressing certain infections caused by susceptible bacteria and protozoa. It is relevant when supportive symptom management is appropriate, particularly in scenarios involving episodic or fluctuating manifestations.

The main therapeutic uses of the medicine are listed in the therapeutic indications. Secnidazole is applied in addressing conditions associated with acute or disruptive episodes such as bacterial vaginosis (BV) in female patients and trichomoniasis. This represents the core domain of use.

Quick Fact: Assists with Symptom Clusters

Secnidazole is commonly used to help with conditions characterized by periods of heightened symptoms and symptoms related to physical discomfort. It may assist with maintaining functional stability and contributes to easing the overall symptom load. This action provides supportive relief when symptoms interfere with routine activities. “The therapy supports patients during episodes of heightened discomfort by assisting with symptomatic relief.” It helps patients cope more steadily during symptomatic phases.

Eligibility and Restrictions for Use

Secnil (secnidazole) is generally indicated for the treatment of bacterial vaginosis and trichomoniasis in adults and adolescents, typically those 12 years of age and older. It is an antimicrobial that falls under the class of nitroimidazole derivatives.

Secnil is contraindicated (should not be used) in several situations, primarily when there is a known hypersensitivity or allergic reaction.

Contraindications and Cautionary Use

Condition Recommendation
Allergy/Hypersensitivity Do not use if you have a known allergy to secnidazole or any other nitroimidazole derivatives (e.g., metronidazole, tinidazole).
Cockayne Syndrome Use is contraindicated due to the risk of severe, irreversible liver toxicity.
Alcohol Consumption Avoid all alcoholic beverages and products containing propylene glycol during treatment and for at least two days (48 hours) after the final dose to prevent a disulfiram-like reaction (e.g., nausea, vomiting, flushing).
Pregnancy/Breastfeeding Use during pregnancy should only occur if clearly needed. Breastfeeding is not recommended during treatment and for 96 hours (4 days) after taking the dose.

Additionally, due to findings from long-term animal studies with related drugs, chronic use of Secnil should be avoided. Patients should be monitored for the development of vulvovaginal candidiasis (yeast infection), as this is a potential side effect of the treatment.

What should I know about interactions with other medicines?

Secnil Interactions with Other Medicines and Products

This section details the officially documented interactions for Secnil (secnidazole) as described in government regulatory prescribing information.


Documented Drug-Drug and Pharmacodynamic Interactions

Interacting Substance/Class Official Regulatory Finding Action Required by Label
Oral Anticoagulants (e.g., Warfarin) Potentiation of the anticoagulant effect; attributed to decreased hepatic catabolism. Increased monitoring of Prothrombin time and INR is required during co-administration and for eight days after Secnil is stopped.
Combination Oral Contraceptives (Ethinyl Estradiol plus Norethindrone) No clinically significant drug interaction was observed in studies. No restriction on co-administration is required.

Interaction with Alcohol and Other Products

Secnil has a mandatory interaction constraint concerning products containing alcohol.

Interacting Substance/Class Official Regulatory Finding Action Required by Label
Alcoholic Beverages, Ethanol, and Propylene Glycol Use is associated with a risk of a disulfiram-like reaction (e.g., nausea, vomiting). Complete avoidance is required during therapy and for at least 48 hours (2 days) after treatment is completed.

Regulatory documents do not list any specific drug combinations as formal contraindications with secnidazole, and no warnings regarding heightened interaction severity in specific patient populations (e.g., hepatic impairment) are explicitly stated in the prescribing information.

Mechanism of Action

Selective Activation within Pathogens

Secnidazole functions as an inactive prodrug that exerts its action via selective toxicity. It is chemically reduced only by specific nitroreductase enzymes found inside susceptible anaerobic bacteria and protozoa. This bioactivation step is critical, as it converts the molecule into the toxic form required to proceed with its mechanism, which leads to the drug's activity being confined largely to the target organisms.


Irreversible Molecular Destruction

The reduction process generates highly reactive and unstable nitro radical anions and related cytotoxic species. These radicals immediately initiate a lethal cascade by causing irreversible damage to the pathogen's essential DNA structure, leading to strand breaks and inhibition of replication. The radicals also damage proteins involved in energy production and cellular function, causing the microbe to lose viability, leading to its clearance from the system.


️ Mechanistic Constraints by Oxygen

A key constraint is the process of futile cycling where oxygen can rapidly re-oxidize the toxic radical intermediate back into the inactive parent drug. This chemical antagonism means the drug's mechanism is strongly influenced by a low-oxygen environment (anaerobiosis). This process underlies the drug's reduced activity against organisms in high-oxygen environments.

Dosage and Administration Information

How to Use Secnil (Secnidazole): Administration Guidelines

This section outlines the administration instructions for Secnil (Secnidazole), detailing the precise method for its use.


Administration Scope

Entity Instruction
Route of administration Oral (by mouth).
Dosing schedule Adults/Adolescents (≥12 years): Typically a single 2 g dose. Pediatric dosing is weight-based (e.g., 50 mg/kg to 75 mg/kg single dose) for certain indications.
Timing in relation to meals May be taken without regard to meals (with or without food).
Frequency pattern Primarily Single-Dose (one-time treatment). For certain amoebiasis regimens, the frequency may be Once Daily for 2–5 days.

Preparation and Procedural Instructions

For products supplied as oral granules:

  1. The entire contents of the packet must be opened and sprinkled onto a small amount of soft food (e.g., applesauce, yogurt, or pudding).
  2. The granules must not be dissolved in any liquid.
  3. The mixture must be consumed within 30 minutes of preparation, and the granules must not be chewed or crunched.
  4. A glass of water may be taken after consuming the prepared mixture.

Use Protocol

The standard protocol defines use as a single, 2 g oral administration, which constitutes the entire prescribed course of treatment. The Administration Integrity rule (no chewing/crunching) is required to maintain the intended properties of the medication. Sexual partners of patients treated for trichomoniasis should be simultaneously treated with the same dose to prevent reinfection.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Secnil

Evidence for Use in Bacterial Vaginosis (BV)

The research into Secnil for Bacterial Vaginosis (BV) has primarily used short-term randomized controlled trials (RCTs). These studies were designed as double-blind and placebo-controlled trials. Research for this indication examined adult women and included two main outcomes: Clinical Cure (which involves the measurement of change in physical signs and symptoms based on defined criteria) and Microbiological Cure (which monitors measurements related to microbial balance). Follow-up typically monitored changes over a short period, often extending to about four weeks (Day 28).

Studies conducted during periods of increased symptom activity documented measurements of clinical and microbiological status at the designated follow-up times. These findings describe group patterns observed in the measurement of symptom change and shifts in microbial balance within the observed populations. However, the existing evidence provides limited insight into long-term outcomes, such as the maintenance of status or the prevention of recurrence beyond the initial assessment period.


Evidence for Use in Trichomoniasis (T. vaginalis)

Research examining Secnil for Trichomoniasis also relies on short-term Phase 3 Randomized Controlled Trials (RCTs). These studies included patients who are adult women and men, as well as some adolescent populations (aged 12 years and older). The core outcome evaluated was the Microbiological Test of Cure (TOC), meaning researchers monitored whether laboratory tests could confirm the parasite had been eliminated shortly after treatment (typically 6 to 12 days later).

Subgroup analyses was studied for women with co-existing conditions such as HIV or Bacterial Vaginosis. The evidence described patterns of microbial clearance observed across the studied populations. Similar to BV, the research provides limited insight into long-term outcomes regarding the sustained absence of the parasite or re-infection rates, as the follow-up durations primarily focused on confirming the initial test of cure.


Understanding Research Gaps and Uncertainty

For intestinal protozoal infections like Amoebiasis and Giardiasis, the evidence base often derives from older clinical trials, retrospective analyses, and systematic reviews from different countries. The evidence quality varies across studies for these uses. The data for certain patient demographics, like specific groups of patients with multiple health issues, remains limited, and results apply only to the populations studied. The research highlights what is known—and what is still uncertain—about Secnil.

Frequently Asked Questions (FAQ)

Common questions about Secnil (FAQ)

Q: Will taking Secnil make me feel drowsy or tired?

Official safety information reports side effects that affect the nervous system, such as dizziness and headache, as common. Drowsiness and unusual tiredness have been reported as being associated with the use of this medicine.

Q: What foods or drinks, if any, are listed as potentially interacting with Secnil?

According to the official product information, there is a mandatory constraint against consuming alcohol or products containing propylene glycol. Beyond this specific warning, official guidance indicates that patients generally continue their normal diet while taking the medicine unless otherwise directed by a healthcare provider.

Q: Is Secnil suitable for individuals with a history of liver issues?

Official regulatory documents advise caution regarding the use of this drug in individuals with liver impairment. The information indicates that the drug's use is subject to special considerations and is generally not recommended for patients with severe liver impairment.

Q: How does the research evidence for Secnil compare to older treatments?

Clinical pharmacology studies describe how the drug works in the body compared to other medicines in the same nitroimidazole class. Clinical pharmacology notes that this drug has a longer terminal elimination half-life than some other drugs in the same class, a factor which supports its single-dose use.

Q: Will Secnil impair my ability to drive or operate heavy machinery?

Official product documents advise caution due to the potential for side effects that affect the nervous system, such as dizziness or drowsiness. Due to these potential effects, official documents advise caution regarding the ability to drive or operate heavy machinery.

Q: Is the medication Secnil considered generic or brand-name?

The active ingredient in this medication is Secnidazole, which is the generic name for the substance. Secnil is a brand name under which the drug is marketed, along with other brand names like Solosec.

Q: How long does it typically take before Secnil starts to work?

Clinical data regarding the drug's activity in the body shows that the maximum concentration (Cmax) in the bloodstream is usually reached in approximately 3 to 4 hours after the dose is taken. This figure describes the time when the active ingredient reaches its peak concentration in the bloodstream.

Q: Does Secnil affect mood or cause anxiety or depression?

While the drug is part of a class that is known to cause effects on the nervous system, such as headache and dizziness, depression and anxiety are generally not listed among the common adverse reactions in official regulatory documents.

Q: Does Secnil interact with blood pressure medications?

Regulatory drug interaction resources do not commonly list a major or moderate interaction with most standard blood pressure medications. However, official information reminds that a healthcare provider reviews all medications, as specific combinations may require additional monitoring.

Q: What kind of interactions are described between Secnil and common over-the-counter painkillers?

Drug interaction checkers from regulatory sources generally report no major or moderate interaction with common over-the-counter painkillers like acetaminophen or ibuprofen-related drugs. However, the healthcare provider should be informed of all products taken for a complete safety assessment.

Q: Are there any known interactions between Secnil and herbal supplements or vitamins?

Official regulatory sources note that the drug may interact with certain vitamins or supplements. Official patient counseling information reminds patients to inform their healthcare provider of all herbal products and vitamins they are taking.

Q: Are there specific age restrictions for taking Secnil, such as for patients over 65?

Official documents for the drug state that clinical studies did not include a sufficient number of patients aged 65 and over. Therefore, there is limited data to definitively determine if their response to the drug is different compared to that of younger adults.

Q: Can people with pre-existing kidney problems take Secnil?

Regulatory information indicates that no specific dosage adjustment is recommended for patients with renal (kidney) impairment. However, regulatory information indicates that caution is generally advised if a patient has severe kidney impairment.

Q: What are the main differences between Secnil and [a similar drug name]?

Clinical pharmacology information compares this drug to other agents in the same class. A key difference noted is its longer terminal elimination half-life and its oral absorption profile, which supports its single-dose regimen.

Q: When was Secnil first approved by major regulatory bodies like the FDA or EMA?

The drug was first approved by the U.S. Food and Drug Administration (FDA) in September 2017 for certain treatment indications.

Q: Is Secnil widely prescribed globally?

Official drug information indicates that the active ingredient, Secnidazole, has been available and used for several decades. It has been used in many countries across Europe, Asia, South America, and Africa.

Q: Why is Secnil only available by prescription?

As an antimicrobial agent, the drug is restricted to prescription use. This is done to ensure its appropriate use only for susceptible infections and to help reduce the risk of developing drug-resistant bacteria.

Q: Does Secnil affect the results of routine lab tests?

Official interaction information indicates that the use of this drug with certain other medications, such as oral anticoagulants (blood thinners), requires increased laboratory monitoring. This includes checking the International Normalized Ratio (INR), to assess the potential effect on those co-administered medications.

Q: What information is available about missing a dose of Secnil?

Given that the most common regimen is a single, one-time dose, the risk of a missed dose is low. Regulatory guidance for multi-dose regimens, where applicable, suggests that the missed dose may be taken when remembered, unless the next dose is due shortly.

Q: Is Secnil a controlled substance in the country I live in?

According to the US Drug Enforcement Administration's Controlled Substances Act (CSA) schedule, Secnil (Secnidazole) is not currently listed as a federally controlled substance.

Q: Where can I find the official patient information leaflet for Secnil?

Official regulatory documents include a section dedicated to Patient Counseling Information that summarizes essential usage and safety details. Full patient leaflets are also made available through various government health resources, such as the National Institutes of Health (NIH) MedlinePlus.

Q: What happens if I accidentally take more Secnil than prescribed? (Informational query)

Official information on overdose states that taking too much of the medication may lead to drug toxicity. Symptoms reported can include severe nausea, vomiting, loss of coordination, and potential neurological effects like seizures or nerve damage.

Q: Can Secnil be prescribed to people with a history of heart conditions?

Clinical pharmacology studies examined the drug's effect on heart rhythm, specifically the QTc interval. The data indicates that the drug has no clinically relevant effect on the QTc interval (a measure of heart rhythm) at therapeutic or even slightly higher doses.

Q: Does Secnil contain common allergens like lactose or gluten?

The complete list of excipients (inactive ingredients) used in the drug formulation is documented in official regulatory materials. Patients with known hypersensitivities to substances like lactose or gluten are encouraged to review this detailed list of ingredients with a healthcare provider.

Q: Are there different brand names for the drug Secnil in other countries?

Yes, the generic ingredient, Secnidazole, is marketed under a variety of different brand names globally, including Secnil and Solosec, depending on the country and manufacturer.

Q: What is the duration of action for a single dose of Secnil?

The drug has a long duration profile in the body, evidenced by its long plasma elimination half-life of approximately 17 hours. This sustained presence in the bloodstream is a key pharmacokinetic factor that supports its use as a single-dose treatment.

Q: How is Secnil generally eliminated from the body?

Regulatory information on pharmacokinetics describes how the drug is processed and cleared. The drug is eliminated from the body through a combination of metabolism by liver enzymes and the excretion of the unchanged drug in the urine.

How should Secnil be stored and disposed of?

How to Store and Dispose of Secnil (Secnidazole)

Secnidazole must be stored under specific conditions to maintain product stability and must be handled carefully.


Storage and Handling

Storage Temperature: Store the medicine at controlled room temperature, typically 20 C to 25 C (68 F to 77 F), with excursions permitted up to 30 C. It is crucial to not freeze the product and to keep it protected from moisture in its original container.

Child Safety: The product must be stored out of the sight and reach of children.

Stability Constraint: If the oral granules are mixed with food, the mixture must be consumed within one hour.


Disposal Requirements

Expired or unused Secnidazole should be disposed of through an authorized drug take-back program. If a take-back program is unavailable, the medicine can be mixed with an unappealing substance, sealed in a container, and placed in the household trash. Do not flush Secnidazole down a toilet or pour it down a sink.

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

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