Drontal Allwormer

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Drontal Allwormer

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 Drontal Allwormer

Quick Facts

Property Description
Active Ingredients Praziquantel, Pyrantel
Form Oral tablet
Pharmacological Class Anthelmintic (Cestocidal, Nematocidal)
Common Use Treatment of intestinal worm infections in cats
Origin Synthetic compounds

Identity and Pharmacological Classification

Drontal Allwormer is a broad-spectrum veterinary anthelmintic agent classified as a combination product, primarily designed to address various intestinal parasites in the feline target audience (cats and kittens). Its formulation is defined by its two distinct synthetic active ingredients: Praziquantel and Pyrantel, which is often present as the salt Pyrantel Pamoate. This drug is categorized by its pharmacological class as an Anthelmintic, specifically operating as both a Cestocidal (targeting tapeworms) and a Nematocidal (targeting roundworms and hookworms) compound. The synthesis of these two different anthelmintics into one product is clinically recognized for establishing comprehensive, broad-spectrum capability against diverse worm infections, a distinctive feature compared to single-agent preparations.

Composition, Form, and General Therapeutic Purpose

The medication is presented as an oral tablet for administration via the oral route, ensuring a measured and stable dose of its active components. The general therapeutic purpose of combining Praziquantel and Pyrantel is to achieve the comprehensive clearance of worm infections by utilizing two separate, effective mechanisms. Praziquantel acts on flatworms by causing rapid muscle contraction and paralysis of worms. Simultaneously, Pyrantel acts as a neuromuscular blocking agent on roundworms, inducing spastic paralysis and immobilization. This synergistic strategy ensures the prompt and efficient dislodgement and expulsion of a wide spectrum of parasites from the digestive tract, resulting in effective overall parasite clearance in cats and kittens.

Regulatory References

  1. NIH MeSH Classification
  2. NIH DailyMed Pyrantel Action

What side effects are possible with Drontal Allwormer ?

Possible Side Effects and Safety Information

The safety profile for Drontal Allwormer for Cats (praziquantel/pyrantel pamoate) is based strictly on data documented in official government regulatory sources, such as the U.S. Food and Drug Administration (FDA) and other national agencies. Adverse reactions are generally considered rare and transient (short-lived).


Documented Adverse Reactions

The officially listed side effects primarily involve two key organ systems, with most effects categorized as rare or noted through post-approval experience.

System-Organ Class Documented Adverse Reactions (Generally Rare)
Gastrointestinal Disorders Vomiting, Diarrhea, Transient Loss of Appetite, Loose Stools
Nervous System Disorders Salivation (Hypersalivation/Drooling), Transient Ataxia (Loss of coordination)

Official Safety Restrictions and Constraints

Certain constraints on use are defined within the regulatory labeling to ensure patient safety:

  • Population Restrictions: The product is contraindicated for use in kittens less than one month of age or weighing less than 1.5 lbs. Use in sick or pregnant animals requires veterinary consultation.
  • Hypersensitivity: Drontal Allwormer must not be administered to animals with a known hypersensitivity or allergy to either Praziquantel or Pyrantel Pamoate.
  • Co-administration Note: Caution is advised regarding the simultaneous use of this product with alternate dewormers or medications containing piperazine, as this may affect the safety profile.

Overdose and Emergency Response

Overdose and when to seek help

Regulatory information documents the official descriptions of overdose and mandated emergency procedures.

Documented Overdose Manifestations

Overdose manifestations are typically described as transient clinical signs, as safety studies show the medication is generally well-tolerated at multiples of the recommended dose. The primary signs of intoxication documented include immediate vomiting (vomition) and excessive salivation. Other potential transient clinical manifestations observed are diarrhea, slight incoordination (ataxia), and temporary loss of appetite. These effects are often self-limiting, with recovery from neurological signs typically complete within 24 hours. There are no explicitly documented severe or life-threatening outcomes listed in the official veterinary labeling.

Mandated Emergency Actions

Regulatory authorities require specific emergency actions when overdose is suspected. For accidental human ingestion, the official mandate is to contact a physician immediately or call a Poison Information Centre. If an overdose is suspected in the animal, the required action is to contact a veterinarian or an animal poison control center without delay for professional guidance. Management is officially described as symptomatic and supportive treatment because no specific antidote is known for the active ingredients.

Therapeutic Uses of Drontal Allwormer

What Drontal Allwormer Treats: Main Uses and Benefits

Drontal Allwormer is commonly used to help address various intestinal worm infestations in felines, focusing on conditions that create noticeable physiological strain. The medication is considered relevant in therapeutic domains involving anthelmintic therapy, providing support that helps ease the overall symptom burden caused by parasitic activity.

The medication addresses the three most prevalent groups of gastrointestinal parasites simultaneously: roundworms, hookworms, and tapeworms (including the common flea tapeworm). This broad-spectrum application is relevant in conditions marked by heightened symptoms of chronic parasitism, such as weight loss, a dull haircoat, and diarrhea. Treatment contributes to the maintenance of functional stability and general digestive comfort.

The medication is used for the management of Tapeworms (Dipylidium caninum, Taenia taeniaeformis), Hookworms (Ancylostoma tubaeforme), and Large Roundworms (Toxocara cati) in cats.

The treatment may be part of symptomatic management within clinical settings that involve acute or recurrent parasitic episodes, including routine preventative programs and the use in vulnerable patient groups like young kittens and breeding queens, where it supports the patient by managing the risk of re-infestation.


Quick Fact: Relief for Parasitism-Related Distress

Symptom Domain Addressed Key Therapeutic Benefit Provided
Gastrointestinal Manifestations (e.g., diarrhea, visible worm segments) Helps address symptom clusters that may become disruptive and interfere with daily comfort.
Physical Decline Indicators (e.g., poor coat quality, weight loss) Supports general well-being during symptomatic phases and assists with maintaining functional stability.

Regulatory References

  1. Drontal (praziquantel/pyrantel pamoate) Tablets for Cats

Eligibility and Restrictions for Use

Eligibility Map: Who can and Cannot Use Drontal Allwormer — Official Regulatory Information

The eligibility for Drontal Allwormer (feline formulation) is strictly defined by regulatory documents based on the animal's age, weight, and clinical status. Official labeling classifies populations into those allowed, restricted, or contraindicated for use.

Eligibility Scope Status Defined by Regulatory Labeling
Populations Allowed Adult cats and older cats; lactating queens (mother cats).
Populations Contraindicated Animals with a known hypersensitivity or allergy to Praziquantel or Pyrantel.
Age/Weight Restrictions Kittens are excluded from use if they are under one month or under 4 to 6 weeks of age, depending on the regional label. They are also contraindicated if they weigh less than 1.5 lbs or a specific minimum kilogram threshold.
Physiological Status Use in pregnant queens is permitted by some regulatory documents, while others impose a restriction or state it is not recommended due to insufficient data.
Drug-Use Constraint The product is contraindicated for simultaneous use with piperazine compounds to prevent adverse interactions.

Official eligibility statements mandate adherence to these rules: the medicine is prohibited for use below the minimum age/weight thresholds, and in cases of documented allergy to its active ingredients. Eligibility is therefore determined by confirming the cat or kitten meets the necessary regulatory-defined criteria for safe application.

What should I know about interactions with other medicines?

The interaction profile for Drontal Allwormer is defined by specific regulatory restrictions and the absence of pharmacokinetic warnings in the official product labeling.

Substance Class Interaction Type Regulatory Restriction Outcome
Piperazine compounds Pharmacodynamic Contraindication Inhibition of the anthelmintic efficacy of the pyrantel component.
Food Administration No Mandatory Restriction Can be administered with food or on an empty stomach.

The most critical restriction is the formal contraindication against the simultaneous use of medications containing piperazine compounds. This is based on a documented pharmacodynamic antagonism, where the regulatory text confirms that the action of piperazine may specifically inhibit the efficacy of the pyrantel component. Co-use with other anthelmintic products or other cholinergic compounds is not recommended in some official product literature due to potential interaction concerns.

Regarding administration, the regulatory labels state that no mandatory timing constraints are imposed by food. The product may be given to the animal on an empty stomach or mixed with food, as there is no documented, clinically significant interaction with meals.

Official product interaction documentation does not list warnings or restrictions concerning metabolic pathways (such as CYP-mediated effects), drug transporters, or population-specific risk considerations (e.g., heightened interaction severity in hepatic impairment). The interaction profile is thus primarily focused on avoiding specific antagonistic medicinal combinations.

Mechanism of Action

Drontal Allwormer acts through a multi-modal mechanism, simultaneously disrupting three separate life-sustaining systems within the targeted parasites.

Causing Parasite Paralysis via Neuromuscular Blockade

The Pyrantel Embonate component targets the parasites' cholinergic neurotransmission system. It acts as an agonist on specific receptors at the worm's neuromuscular junction, leading to constant, uncontrolled signaling. This persistent over-stimulation causes spastic, irreversible paralysis in nematodes (roundworms and hookworms), resulting in a loss of muscular anchorage.

Disrupting Cellular Structure and Ion Balance

The Praziquantel component rapidly increases the permeability of the tapeworm's outer layer, the tegument. This disruption causes a massive calcium ion influx ( Ca^2+), which triggers acute, intense tetanic muscular contractions. This molecular action leads to the worm's structural breakdown and vacuolization.

Inhibiting Parasite Energy and Metabolism

The third component, Febantel, is metabolized into an active form that binds to beta-tubulin in the worm's cells, preventing the assembly of microtubules. This molecular inhibition disrupts the parasite's nutrient absorption and transport processes, leading to cellular energy depletion.

Dosage and Administration Information

How to Use Drontal Allwormer

Administration of Drontal Allwormer follows weight-based protocols and specific cyclic schedules. The medication is an oral tablet administered as a single dose by mouth.


Official Dosing and Frequency

Instruction Entity Detail
Route of Administration Single-dose oral administration
Standard Dose Rule Calculated based on the cat’s body weight; typically, one tablet per 4 kg body weight (or equivalent formulation).
Routine Adult Frequency A single dose administered every three months (intermittent use pattern).

Procedural and Age-Specific Instructions

The correct use protocol mandates specific conditions and schedules based on age group.

Special Use Case Procedural Instruction
Administration Condition The tablet may be given with food or on an empty stomach. Fasting is not required, but the cat must be weighed prior to dosing to ensure accuracy.
Kitten Schedule Treatment is scheduled as single doses at 4, 6, 8, and 12 weeks of age, followed by the adult 3-monthly regimen. The product is not intended for use in kittens under 1 month of age.
Breeding Queen Schedule Specific dosing is required prior to mating, 10 days before kittening, and at 2 and 4 weeks post-kittening.

The overall use protocol emphasizes a precision, weight-based model integrated into distinct cyclic schedules. These schedules—the 3-monthly interval for adult maintenance and the accelerated schedules for kittens and breeding queens—define the standardized administration pattern.

Recent Clinical Evidence

Drontal Allwormer: Recent Clinical Evidence

Evidence for Use in Broad-Spectrum Intestinal Parasite Clearance

Research examined this combination product for its role in veterinary settings involving intestinal parasites, including large roundworms, hookworms, and tapeworms, which are common in felines. The evidence reviewed in the product's regulatory submission included two main types of research. The first includes pivotal, well-controlled laboratory studies, which typically use controlled settings and direct physical examination to assess the presence of parasites before and after treatment. The second type involves multi-site clinical field trials, which observe responses in cats with natural, existing infections across various veterinary settings.

These studies were focused on outcomes related to physical discomfort and systemic functional imbalance caused by parasitic activity. Research primarily explored the efficacy of parasite removal, meaning the extent of worm removal in the digestive tract. Studies also monitored the reduction of parasite eggs measured in fecal samples in the field settings. Findings described patterns observed in the studies related to the removal measurements of the target worms.

Design and Methods of Clinical Evaluation Studies

Studies explored the product using strict criteria. In the laboratory setting, researchers used necropsy to confirm the number of worms remaining, providing a direct measurement of clearance. In the clinical field trials, researchers measured change over time by comparing fecal egg counts before and after the treatment was administered. The primary goal of the research was to evaluate the measured removal of each parasite type.

Findings from the controlled studies contribute to understanding the patterns observed in the observed populations following treatment. For example, some initial laboratory measurements of removal rates for large roundworms (Toxocara cati) were observed in some studies to be slightly lower than expected in specific trial settings, although subsequent research described higher clearance measurements. Studies measured changes during the study period, contributing to the available evidence.

Research on Specific Populations

The research was evaluated in studies involving a mixed group of felines. Study populations included cats and kittens with naturally acquired infections. Studies examined subjects ranging widely in age, from young kittens starting at one month old up to senior cats 14 years of age. Studies also included a variety of weights and different breeds.

This means the data show patterns related to the outcomes observed across various typical feline populations encountered in veterinary practice. However, evidence is limited for certain subgroups, such as pregnant or breeding queens, and more focused research examining specific comorbidities is not fully established. Results apply only to the populations studied and data for certain groups remain insufficient.

Long-Term Observations and Follow-Up Duration

Most pivotal research concentrated on research exploring short-term symptom changes, specifically the clearance of the parasite burden. Primary efficacy endpoints was evaluated in the short-term, typically within a few days to about one week after treatment. Follow-up fecal examinations were observed in some studies over an intermediate duration, lasting approximately two to four weeks.

The follow-up durations were limited, meaning that long-term effects are not fully established. There is limited information for long-term outcomes, such as the durability of the parasite clearance or the frequency of subsequent infections. Studies observing responses over defined time intervals therefore offer insight into short-term changes but do not offer a complete picture of maintenance or chronic management.

Evidence Gaps and Areas of Uncertainty

The evidence highlights what is known—and what is still uncertain—about the product’s research base. One key limitation is that the total subject count in the clinical field trials was modest (fewer than 100 completed cases), which means the results apply only to the populations studied.

Additionally, comparative evidence is lacking, as the research was structured to assess the combination product itself, rather than comparing it directly against other single-agent or multi-agent treatments. The short follow-up durations mean that long-term effects are not fully established and the research exploring durability of effect is not well characterized. Data for certain groups remain insufficient, and research is ongoing in the broader field of veterinary parasitology.

Key Studies & References

  1. FDA Freedom of Information Summary NADA 141-008: Original Approval of Praziquantel and Pyrantel Pamoate Tablets for Cats
  2. Label: DRONTAL (praziquantel, pyrantel pamoate) tablet - DailyMed

Frequently Asked Questions (FAQ)

Common questions about Drontal Allwormer (FAQ)


Q: How quickly does Drontal Allwormer start to work after a single dose?

The product's mechanism of action begins shortly after administration to target the parasites.

Clinical studies primarily evaluate the efficacy (the extent of worm removal) within a short-term window, generally ranging from a few days up to about one week after the single treatment dose.


Q: Is it normal to see worms in the stool after using Drontal Allwormer?

The medication works by paralyzing and disrupting the worms, causing them to be expelled from the animal's digestive tract.

Because of this process, it is possible for the owner to see worms or worm segments passed in the feces. The worms may also be completely digested and not visible in the feces.


Q: How long after treatment might dead worms or segments be passed?

Worms may be expelled shortly after treatment and may continue to be passed in the droppings for up to 48 hours.

If passage of worms or segments continues beyond this short timeframe, users are generally advised to monitor the situation.


Q: Does Drontal Allwormer have a residual or lasting protective effect against re-infestation?

The product is designed for the treatment of existing infections, and it does not provide long-term protection against re-infestation.

Official information notes that re-infestation is certain to re-occur unless ongoing environmental control measures are undertaken, such as managing the presence of fleas or contaminated areas.


Q: Are there any known interactions between Drontal Allwormer and common medications like NSAIDs or antibiotics?

Regulatory labels list a formal contraindication against using Drontal Allwormer with medications containing piperazine compounds due to potential antagonism.

Official product information typically does not list specific warnings for co-use with common drug classes such as Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) or common antibiotics.


Q: What common supplements or foods might interact with Drontal Allwormer?

According to the official product information, Drontal Allwormer can be given with food or on an empty stomach, as fasting is not required for efficacy.

Official regulatory documents do not typically list warnings regarding specific food types or common supplements.


Q: Does the medication need to be stored in a particular way to maintain its effectiveness?

Yes, proper storage is necessary to maintain the quality and effectiveness of the medication.

It must be stored at controlled room temperature, typically between 20 C and 25 C, and it must be protected from both light and moisture.


Q: What are the signs that a worm infestation might be heavy or persistent, requiring a vet visit?

If a worm problem persists or if the animal's condition worsens or does not improve after treatment, official safety information recommends consulting a veterinarian for further guidance.

This caution applies to any severe, ongoing, or unusual health issues observed.


Q: What type of worms are considered a severe risk to human health, which Drontal Allwormer helps control?

Official product information highlights that the medication is effective against certain parasites, such as Echinococcus spp. (Hydatid tapeworm), which are classified as a hazard to humans (a zoonotic risk).

Control of these worms in pets helps reduce the overall risk of human infection.


Q: Does Drontal Allwormer protect against heartworm as well as intestinal worms?

Official regulatory labels explicitly state that Drontal Allwormer is formulated to treat intestinal worms only.

The product does not control heartworm in cats, and a separate heartworm preventative medication would be required for that purpose.


Q: Is it normal for an animal to seem a bit more tired or lethargic after taking Drontal Allwormer?

The officially listed side effects primarily involve the nervous system and gastrointestinal tract.

Lethargy (a state of tiredness) is occasionally reported as an uncommon side effect in regulatory adverse event data.


Q: Why do some pets seem hyperactive or anxious after a dose of Drontal Allwormer?

Official regulatory adverse event data includes non-specific reports of behavioral changes in some animals following treatment.

However, hyperactivity or anxiety are not commonly listed as specific, documented adverse reactions, but any unusual behavior should be monitored.


Q: Why is it necessary to control fleas when also treating with Drontal Allwormer?

The need for flea control is directly related to the life cycle of one common tapeworm, Dipylidium caninum.

Official warnings explain that fleas serve as the intermediate hosts for this tapeworm, meaning re-infestation is highly likely if flea control is not also maintained.


Q: Are there different Drontal Allwormer formulations, like tablets, chews, or a suspension?

Yes, depending on the specific product line and region, the medication can be available in different forms to suit the species and age of the animal.

These formulations typically include various sized oral tablets, chewable forms, and a suspension (a liquid form) for very young animals.


Q: Do the ingredients in Drontal Allwormer cause a bitter taste that makes administration difficult?

Product descriptions often note that the tablet or chewable forms are designed to be easily accepted by the animal.

Many formulations are described as being flavoured (e.g., meat or liver flavor) to help ease the process of administering the medication.


Q: What should be done with the animal's stool after administering Drontal Allwormer?

To minimize the risk of re-infestation and to protect the environment, special precautions are advised.

Regulatory guidelines recommend that feces should be collected and properly disposed of for a designated period following treatment to minimize environmental contamination.


Q: Can environmental contamination be reduced with the correct use of Drontal Allwormer?

Yes, proper administration of the product is part of an overall parasite management strategy.

Regulatory recommendations stress that reducing environmental contamination is crucial and requires the daily disposal of droppings in addition to treating the animal.


Q: Does Drontal Allwormer treat common protozoan parasites in addition to worms?

Drontal Allwormer is classified as a cestocidal and nematocidal agent (it kills worms).

However, some formulations, such as those intended for dogs, are also registered to control the shedding of cysts of the protozoan parasite Giardia spp.


Q: What is the significance of the tablet being 'flavoured'?

The tablets are intentionally flavoured, often with a liver or meat component, to increase the medication's palatability.

This is done to make the product more readily accepted by the animal, easing the process of administration for the owner.


Q: Does Drontal Allwormer have a strong odor that might deter some animals from taking it?

Official safety data sheets, which describe the physical properties of the product, often classify the tablet's odor as slight or musty.

This generally suggests the smell is not strong enough to deter most animals, especially when the product is also flavoured.


Q: Is it safe to administer Drontal Allwormer to an animal that is already on a monthly heartworm preventative?

Regulatory sources indicate that the product may be administered as part of a comprehensive parasite control program.

It may be combined with other common treatments, such as a monthly heartworm preventative or a flea and tick treatment.


Q: Is Drontal Allwormer known to be effective against Giardia?

While the primary purpose is to eliminate worms, some formulations (typically the canine version) are registered for use against the protozoan parasite Giardia.

Using the treatment for Giardia requires a different, multi-day dosing protocol than the standard single dose for worms.


Q: What is the recommended number of consecutive days for Drontal Allwormer use when treating Giardia?

For formulations that are registered to control the shedding of Giardia cysts, a different administration schedule is typically required.

Official guidelines state that for this specific purpose, the product is usually administered once daily for 3 consecutive days.


Q: Why are some people advised to retreat their pets more frequently than the standard three months?

The standard retreatment interval is every three months for routine control, but regulatory information accounts for specific regional risks.

Retreatment at a shorter interval (e.g., every six weeks) may be recommended in regions where specific severe parasites, such as the Hydatid tapeworm, are a known and serious risk.


Q: Are there different tablet sizes available for different animal weights?

Yes, to facilitate accurate dosing, which is essential for both safety and efficacy, the product is often available in different sizes or strengths.

These different tablet strengths are designed to cover various weight ranges, such as for small, medium, and large animals.

How should Drontal Allwormer be stored and disposed of?

Storage and Disposal Conditions for Drontal Allwormer

Drontal Allwormer tablets must be maintained at controlled room temperature, specifically between 20 C and 25 C (68 F to 77 F). The product must be protected from moisture and light and should be stored in its original container, which must be kept tightly closed.

Storage Protection

It is mandatory to keep the product out of the sight and reach of children and store it away from food or animal feeding stuffs. Storage temperatures should not exceed 30 C unless brief excursions are permitted by labeling.

Disposal Requirements

Unused or expired product must be disposed of according to local regulations or via an approved waste site. It is strictly required not to flush the product into surface water or the sanitary sewer system due to its toxicity to aquatic life.

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

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