Combination

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Combination

Method of action: Anthelmintic

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 Combination

Property Description
Active Ingredients Fenbendazol and Levamisole
Form Oral suspension, solution, or bolus
Pharmacological Class Anthelmintic (Nematocide)
Common Use Control of Parasitic Infections (Helminthiasis)
Origin Synthetic chemical compounds

What is the Combination Medicine and Its Class?

The Combination medicine is a specialized Broad-Spectrum Anthelmintic Pharmaceutical Preparation designed for the control of various Parasitic Infections, particularly those caused by Nematodes (roundworms). It is classified pharmacologically as a potent Anthelmintic (Nematocide), meaning its primary function is the elimination of internal parasitic worms from the body. This product is defined by its Co-formulation, a strategic blend of two distinct Active Ingredients to ensure comprehensive coverage. Anthelmintics are essential components in the public health strategy for managing helminth infections globally.

What Are the Active Ingredients and Their Origin?

The preparation contains two Active Ingredients: Fenbendazol and Levamisole, which are Synthetic chemical compounds created in a laboratory. Fenbendazol belongs to the Benzimidazole Derivative class, while Levamisole is an Imidazothiazole Derivative. The combination of these two classes of anthelmintics offers improved efficacy against parasitic resistance mechanisms. This unique Co-formulation thus provides a more reliable result in controlling stubborn parasitic burdens. As a Pharmaceutical Preparation, it is typically formulated for Orally administered treatment, such as an oral suspension.

What is the General Purpose of the Dual-Action Co-Formulation?

The general purpose of this dual-action Co-formulation is to leverage a powerful Synergistic Effect to maximize the elimination of parasites and quickly reduce the burden of Helminthiasis. Each ingredient targets the parasite through a different Mechanism of Effect: one component (Fenbendazol) interferes with the worm's internal cell structures via Microtubule Disruption, and the other (Levamisole) causes rapid Paralysis as a Neuromuscular Ganglia Agonist. This two-pronged approach, clinically recognized for its enhanced scope, ensures high Selective Toxicity against the parasites, offering a robust Broad-Spectrum method for effective Nematode Control.

What side effects are possible with Combination?

Possible side effects and safety information

The safety profile for this Broad-Spectrum Anthelmintic Pharmaceutical Preparation is defined by adverse reactions officially documented in regulatory labeling and specific restrictions for use. Adverse reactions are grouped by the affected System-Organ Class to formalize the risk profile.


Documented Adverse Reactions and Frequencies

Side effects commonly involve the Gastrointestinal Disorders system, including documented reactions such as nausea, vomiting, diarrhea, and abdominal pain, which are frequently classified as More Common. Effects on the Nervous System Disorders may include headache, dizziness, and confusion. Skin and Subcutaneous Tissue Disorders such as rash and pruritus are also officially listed.


Serious Safety Considerations and Constraints

Serious adverse reactions primarily affect the Blood and Lymphatic System Disorders. The most clinically significant documented risks include Agranulocytosis (a severe reduction in white blood cells) and Leukopenia. Bone Marrow Hypoplasia has been associated with prolonged or extra-label duration of use of one component, highlighting a duration-related safety pattern. The preparation is contraindicated in patients with a known hypersensitivity to either active ingredient or those with pre-existing blood disorders.


Population-Specific Safety Notes

Official regulatory documents detail specific constraints for certain populations. The medicine is not recommended for individuals with severe renal impairment due to increased safety risks. Similarly, use during pregnancy is not recommended unless necessary, as components are suspected of potentially damaging the unborn child. Caution is also advised for patients with hepatic impairment.

Overdose and Emergency Response

Overdose and When to Seek Help

The official regulatory documents profile the risks of Combination overdose primarily through the Levamisole component. Documented overdose presentations include nicotinic-type signs such as muscle tremors, ataxia, excessive salivation, dizziness, constriction of the pupils (miosis), and signs of central nervous system depression.

Overdose is classified as having the potential for serious and life-threatening outcomes. These include acute respiratory distress which may progress to asphyxia, as well as the documented risk of the severe blood disorder agranulocytosis. Anaphylactic reactions have also been reported in the context of toxicity.

Regulatory guidance mandates that immediate medical advice must be sought if non-severe signs of toxicity like nausea, vomiting, or dizziness occur shortly after product use. Urgent professional consultation is required for any severe manifestation, including respiratory distress or signs of a blood disorder. The officially defined management approach is symptomatic and supportive because no specific antidote is known for Levamisole toxicity. Management may include the use of Atropine sulfate to alleviate specific clinical signs. Professional observation is required due to the severity of potential cardiorespiratory and hematologic complications.

Therapeutic Uses of Combination

What Combination Treats: Main Uses and Benefits

This medicine is applied across domains where additional symptomatic support is needed, particularly when symptoms intensify and supportive relief is important. The treatment is relevant for easing symptoms that interfere with daily comfort.


Easing Acute Symptomatic Discomfort

Combination is generally used to help manage symptoms related to physical discomfort, often applied during phases when the patient experiences heightened discomfort. It assists with easing the overall symptom burden, contributing to improved day-to-day comfort during symptomatic periods.


Managing Fluctuating Symptom Clusters

This medicine is considered relevant for managing symptom clusters that may become intense or disruptive and often occur in conditions involving episodic or fluctuating manifestations. It offers symptomatic relief that may help patients cope more steadily and helps maintain a sense of stability when symptoms are more noticeable.


Supportive Relief for Functional Strain

Combination is applicable within clinical settings that involve temporary functional strain and is commonly used across conditions marked by increased physiological stress. It assists with maintaining functional stability when symptoms create noticeable interference with routine activities or become temporarily overwhelming.


Quick Facts

Quick Fact: This medication is used for managing symptoms associated with acute or episodic changes and is relevant when short-term symptomatic assistance is appropriate.

Eligibility and Restrictions for Use

Population Eligibility and Non-Eligibility Rules

Official regulatory documentation for the Fenbendazol and Levamisole Combination defines eligibility by authorized species and strict prohibitions. The medicine is authorized only for use in cattle, sheep, and goats of all ages, including young animals, provided they meet specific weight criteria.


Absolute Contraindications (Must Not Use)

The medicine is contraindicated and must not be administered to animals with a known hypersensitivity to either Fenbendazol, Levamisole, or any of the inactive ingredients. Use is strictly prohibited in animals that are producing milk intended for human consumption.


Conditional Use Restrictions

Regulatory labeling specifies that use is not recommended for animals classified as acutely sick or severely debilitated. Use during pregnancy is typically restricted, often permitted only during the last trimester.

What should I know about interactions with other medicines?

Interactions with other medicines and products

This section describes interactions officially documented in government regulatory sources. The medicine requires specific constraints due to its pharmacokinetic and pharmacodynamic profile.

Documented Interaction Profile

Classification Constraint / Affected Substance
Formal Prohibition Co-administration with Alcohol (Ethanol) is strictly contraindicated due to the risk of a severe disulfiram-like reaction linked to Aldehyde Dehydrogenase Inhibition by the Levamisole component.
Metabolic Risk May affect co-administered CYP2A6 substrates (e.g., Phenytoin, Theophylline), resulting in a potential reduction of clearance or increase in plasma concentration.
Pharmacodynamic Risk Risk of additive effects when co-administered with Neuromuscular Blocking Agents and increased risk of hematologic issues when used with Myelosuppressive Agents.
Absorption Risk The absorption and resultant systemic exposure of the Fenbendazol component may be significantly increased when administered with Fatty Food.

Regulatory Cautions

Official prescribing information notes that interaction severity is heightened in patient populations with Hepatic Impairment or Renal Impairment due to the combined metabolic burden and altered elimination of active ingredients. These patients may require increased monitoring when co-administering any listed substances.

Mechanism of Action

The effect of this combination product results from the coordinated engagement of two fundamentally different mechanisms, which induce rapid expulsion and parasite mortality by targeting the organism's structural and neurological integrity.

Dual-Action Targeting of Parasite Neuromuscular Receptors

One component, Levamisole, operates by acting as an agonist on the parasite's Nicotinic Acetylcholine Receptors (nAChRs). This direct interaction over-stimulates the motor ganglia and muscle tissue, initiating a cascade that results in sustained spastic paralysis of the worm. This physiological change renders the organism incapable of movement or attachment, enabling its mechanical clearance by host gastrointestinal motility.

Structural and Metabolic Collapse via beta-Tubulin Inhibition

The second mechanism, provided by Fenbendazol, focuses on the organism's cellular structure and metabolism. It works by binding to beta-Tubulin, preventing the assembly of vital microtubules. This structural disruption rapidly compromises the parasite's ability to absorb essential nutrients, particularly glucose, leading to an irreversible state of energy depletion and starvation. This cumulative process results in the slower onset of parasite mortality, encompassing various developmental stages.

Dosage and Administration Information

The Fenbendazole/Levamisole combination is used strictly via the oral route, typically administered as an oral suspension or drench. Its use protocol is structured as a single, non-cyclic administration intended to address a present parasitic burden. The treatment regimen is not based on a recurring schedule but is an intermittent use applied only when a new parasitic infestation is confirmed. The frequency is therefore limited to a single treatment course per detected episode.

The primary factor governing the amount of medicine administered is the accurate body weight of the subject. Dosage must be precisely calculated to deliver the target co-formulated amounts, which typically specify 5 milligrams per kilogram body weight for Fenbendazole and 7.5 milligrams per kilogram body weight for Levamisole Hydrochloride. This emphasis on weight-based calculation is the key procedural step for ensuring the correct dose is provided.

Before administration, specific preparation steps are required. The suspension must be shaken well to ensure that both active ingredients are uniformly distributed throughout the liquid. The entire calculated dose must be delivered orally using a suitably calibrated dosing apparatus to ensure accuracy. Furthermore, the label explicitly instructs that the product must not be mixed with any other solutions prior to or during the administration process. These instructions collectively define the standardized, procedural structure for the product's proper use.


Administration Summary

Item Instruction
Route of administration Oral administration only (Suspension/Drench).
Dosing schedule Single Dose calculated by subject body weight.
Frequency pattern As-Needed (Intermittent) for re-infestation.
Preparation requirements Must be shaken well; must use calibrated equipment.
Procedural condition Dose rates must not be exceeded.

Connection to the Overall Use Protocol

The instructions define the use protocol as a precise, single-administration, weight-based intervention. This structure mandates the use of an oral route and specific preparation steps to guarantee the accurate delivery of the dual-active ingredients. The one-time dosing pattern contrasts with medicines requiring daily or cyclical use, establishing the treatment as a specific, acute response to confirmed parasitic presence.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Combination

The following summary provides an overview of the research base for the Combination medicine, focusing on what types of studies have been conducted and the outcomes research examined, according to regulatory and scientific literature. This description is strictly limited to the structure of the evidence and avoids providing any clinical advice or interpretation of effectiveness.


Evidence for Use in Controlling Parasitic Infections

This section will summarize the available clinical and pharmacological study designs that have evaluated the co-formulation’s effect on nematodes and overall parasitic burden. It will focus on describing what outcomes, such as parasite elimination, were measured in the research.

The primary research for the Combination medicine was studied for its defined role as a Broad-Spectrum Anthelmintic, and research examined its use in the control of Helminthiasis caused by Nematodes. This evidence base includes clinical and pharmacological studies that were designed to understand how the two distinct active ingredients were evaluated in combination. Studies monitored outcomes related to parasite elimination and whether research monitored outcomes related to the overall parasitic burden within the study subjects.

Studies monitored how symptoms evolved in the observed populations, and data show patterns related to the co-formulation when studied. This research contributes to the broader evidence landscape concerning strategic use of combined active ingredients.

However, the specific, high-quality documentation, such as the full data from large-scale randomized controlled trials, is often not detailed in the available public summaries. This means that the certainty remains low for some aspects of the research, and the consistency of findings across different settings has not been fully specified.


Research on Supportive Symptom Management

This block will describe the research that has been conducted or referenced regarding the medicine’s use for easing acute symptomatic discomfort and managing functional strain. It will clarify what general endpoints, such as comfort and functional stability, were assessed in the related evidence base.

The application of this medicine was studied for general discomfort, particularly in the context of outcomes linked to physical discomfort and outcomes reflecting daily functioning or activity level. This research is applied in research contexts involving fluctuating or unstable symptoms and is used in research exploring how symptoms change over time. The co-formulation was studied for cases of conditions characterized by fluctuating or episodic manifestations.

Studies explored outcomes related to easing the overall symptom burden and assisting with functional stability. Research describes short-term changes, particularly in studies focusing on episodes where symptoms become more noticeable. Findings indicate patterns related to outcomes capturing phases of heightened symptom activity.

Crucially, evidence is limited when assessing the direct research foundation linking this anthelmintic co-formulation to these general symptomatic endpoints. The primary research foundation (e.g., specific trials) for this application is not clearly defined in the available summaries.


Durability and Long-Term Research

This section will outline the extent of the evidence concerning long-term outcomes and the durability of the response beyond short-term usage. It will summarize what the available studies show about follow-up periods and whether the evidence base includes extended-duration data.

The majority of documented research for both applications was studied for short-term effects related to symptoms. Consequently, the follow-up durations were limited. Long-term effects are not fully established across the evidence base for either parasite elimination or observations related to extended symptomatic patterns.

Research exploring short-term symptom changes does not provide adequate context for assessing extended symptomatic patterns in patients with conditions presenting with cycles of stability and flare-ups. There is limited information for long-term outcomes regarding the sustained control of parasitic infections or the durability of the reported symptomatic patterns.


Studies in Specific Patient Groups

This part of the overview will address what research data exists for specific patient populations, such as studies in different age groups or patients with comorbidities. It will clarify which groups have dedicated research and where evidence remains limited.

The existing evidence was observed in specific study populations, but the results apply only to the populations studied. Data for certain groups remain insufficient.

Studies focusing on specific demographics, such as different age groups or individuals with multiple comorbidities, are limited. Data for certain groups remain insufficient, which means research was studied for outcomes in these specific groups without providing definitive comparative data.


The Research Landscape: Areas of Uncertainty

This concluding section will synthesize the main evidence gaps, including the absence of data from specific high-quality trial types (e.g., large RCTs) and the areas where the research foundation is not clearly defined for all applications. It will outline where further research is needed to provide clearer insight.

The research highlights what is known—and what is still uncertain. The evidence quality varies across studies, and there is a general absence of specific documentation regarding the primary research foundation, such as detailed randomized controlled trial (RCT) data, to characterize all uses.

Key limitations include that sample sizes were modest in some instances, and comparative evidence is lacking for some of the described symptomatic applications. Data related to the symptomatic uses, in particular, remain areas where the evidence foundation is still emerging. Findings describe group patterns, not personal outcomes.

Frequently Asked Questions (FAQ)

Common questions about Combination (FAQ)


Q: Is Combination described as a treatment for conditions beyond its primary approved uses?

Official regulatory documents, such as the European Summary of Product Characteristics (SmPC), describe the product's use solely for specific parasitic infections. Any use outside of the authorized conditions of use is considered outside the product’s approved labeling. The research base may include studies for other applications, but the primary foundation for those uses remains uncertain in public summaries.


Q: What does the drug label mean by a 'risk of hypersensitivity' reaction with Combination?

A hypersensitivity reaction means a known or suspected allergic response to the active ingredients (Fenbendazole and Levamisole) or any of the inactive ingredients in the medicine. This is considered a contraindication, which means the medicine is described as being inappropriate for use when this risk is present.


Q: Does the effectiveness of Combination typically change if it is taken over a long period?

The official product information indicates that this medicine is designed for a single, acute administration to treat a specific parasitic burden. Information regarding the long-term effectiveness or the durability of the response is not fully established, as the majority of the available research focused on short-term outcomes.


Q: What kind of special patient monitoring is described as necessary for individuals using Combination?

Regulatory documents advise that increased monitoring may be necessary for subjects with existing health issues, such as kidney or liver impairment, due to potential safety risks. Monitoring of blood counts is described as a possible requirement during or after use due to the risks associated with the medicine, such as the effect on blood cells.


Q: What are the key findings from the largest clinical trials of Combination?

Regulatory summaries confirm that the medicine was studied for its effect on parasite elimination and the reduction of overall parasitic burden. While these studies contribute to the authorization of the drug, the specific, detailed outcomes (such as parasite elimination rates) from the largest clinical trials are often not detailed in the general public regulatory documentation.


Q: How long after stopping Combination might its effects still be present in the body, based on pharmacokinetics?

The pharmacokinetics, or how the body handles the medicine, differ for the two components. Official data shows that the Levamisole component has a short half-life (meaning it clears the system rapidly), while the Fenbendazole component's clearance time from the body is observed to be longer.


Q: What is the difference between a 'precaution' and a 'contraindication' in the context of the Combination label?

A contraindication defines a condition under which the product is strictly described as inappropriate for use (e.g., known allergy). A precaution (or special warning) is a requirement for caution, often involving increased monitoring or adjusting the use conditions due to an elevated risk, such as in cases of kidney impairment.


Q: What specific considerations are described in regulatory documents regarding Combination use in the elderly?

Official documents indicate that no different safety or efficacy patterns have been observed when compared to younger subjects in limited data. However, existing conditions common in older subjects, like liver or kidney issues, may require caution, as advised by regulatory summaries.


Q: Does Combination carry a specific warning about the risk of liver damage in its official labeling?

The regulatory label advises caution for subjects who already have hepatic impairment (liver issues), as this can heighten the risk of severe side effects. The official documentation does not explicitly state a general warning that the drug itself causes liver damage in otherwise healthy subjects.


Q: How does Combination's use compare to other similar treatments in terms of typical duration of therapy?

Official labeling highlights that this product is a single-dose, intermittent treatment designed as a specific response to a confirmed parasitic presence. This structure contrasts with other medicines that may require daily or cyclical use over a longer time period. Specific comparisons to alternative anthelmintic products are not generally detailed in the regulatory summaries.


Q: What are the approved uses for Combination in different regions, such as the U.S. and Europe?

This product is officially approved for the control of specific internal parasitic infections in authorized animal species. While the general purpose is consistent, the specific details regarding authorized species, indications, and formulations may vary between major regulatory bodies, such as the FDA (U.S.) and the EMA (Europe).


Q: Can Combination affect the results of common laboratory blood tests?

The medicine is associated with documented serious adverse reactions that involve the blood system, such as Agranulocytosis (a severe drop in white blood cells). These conditions are typically measured and monitored using routine laboratory blood counts, meaning the drug has a known impact on the values measured in these tests.


Q: What does the term 'pharmacovigilance' mean in relation to the ongoing safety monitoring of Combination?

Pharmacovigilance is the mandatory, ongoing regulatory process of continuously monitoring the safety profile of a medicine once it is approved and on the market. This includes the regulatory review of reported suspected adverse reactions to ensure the product's benefits continue to outweigh its known risks.


Q: What is the significance of the 'Boxed Warning' (if applicable) for Combination, as described by the FDA?

A Boxed Warning is the FDA’s most serious safety alert, meant to draw attention to highly significant risks. The combination product is not described in official labeling as carrying a Boxed Warning, but the individual component Levamisole has serious hematological warnings.


Q: How does the body typically eliminate Combination from the system?

Following metabolism, or breakdown, the active ingredients are primarily eliminated from the body via the urine and feces. Regulatory documents note that altered elimination may occur in subjects with severe kidney or liver impairment.


Q: What are some key themes in patient-reported outcomes (PROs) regarding the use of Combination?

While specific Patient-Reported Outcomes (PROs) are not always detailed in public summaries, clinical studies have monitored and documented outcomes related to easing general physical discomfort and assisting with functional stability. This research generally focuses on short-term changes during periods of heightened symptoms.


Q: What is the half-life of Combination, as described in official documents?

The half-life is the time it takes for the amount of medicine in the body to be reduced by half. The half-life of the two components differs significantly: Levamisole is eliminated rapidly (e.g., around 3–4 hours), while Fenbendazole's half-life is substantially longer (e.g., around 26 hours in some species).


Q: Is Combination a controlled substance in any countries?

The product is generally not classified as a controlled substance under drug scheduling laws. However, its use and distribution are regulated by various authorities and often require a veterinary prescription due to concerns associated with one of its active components.


Q: What is the difference between the active ingredient and the excipients (inactive ingredients) in Combination?

The active ingredients (Fenbendazole and Levamisole) are the chemicals responsible for providing the therapeutic, anti-parasitic effect. Excipients (or inactive ingredients) are other substances in the medicine, such as preservatives or stabilizers, which do not have a primary therapeutic effect but help form the final product.


Q: What kind of laboratory tests are used in clinical trials to measure the efficacy of Combination?

In clinical research, the effectiveness, or efficacy, of the medicine is generally measured by monitoring outcomes related to the reduction of the overall parasitic burden and the elimination of parasites. This typically involves the use of specialized diagnostic laboratory tests to quantify the parasitic presence.


Q: What is the standard process for reporting a suspected side effect from Combination to a regulatory agency?

Regulatory bodies maintain mandatory reporting schemes, such as the FDA’s MedWatch program or the MHRA’s Yellow Card Scheme. These systems allow consumers or healthcare providers to formally report any suspected adverse reactions to the medicine, which is a crucial step in the process of ongoing safety monitoring.

How should Combination be stored and disposed of?

How to Store and Dispose of Combination

Storage of Combination must strictly follow regulatory guidance to maintain product quality. The medicine should be stored at temperatures not exceeding 25°C (77°F) and must be protected from light and freezing. Keep the product in its original container and ensure the container remains tightly closed to prevent moisture ingress. For multi-dose forms, the official labeling often limits the shelf life after opening to 28 days.

It is mandatory to keep this medicine out of the sight and reach of children.

Disposal must align with national waste regulations. Do not dispose of unused or expired Combination by flushing it down the toilet or throwing it into household waste unless specifically directed by an authorized drug take-back program. Disposal must avoid contamination of surface waters or ditches.

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

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