Cydectine

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Cydectine

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Medically reviewed

Rosario Oropesa

Last updated on 22/12/2025

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

Overview of Cydectine

Quick Facts

Property Description
Active Ingredient Moxidectin
Forms Solution for Injection, Oral Gel, Spot-on Treatment
Pharmacological Class Anthelmintic / Endectocide
General Purpose Broad-spectrum parasite control
Origin Semi-synthetic (Milbemycin Derivative)
Key Feature Unique structure allows for sustained release and longer activity.

Cydectine is a commercial brand name for a medicinal product that derives its therapeutic power from the active ingredient, Moxidectin. The drug’s identity is founded on its classification as an endectocide, which means it is designed for the comprehensive treatment and control of both internal and external parasitic infestations.

Moxidectin: Origin, Composition, and Pharmacological Class

The active substance Moxidectin is a potent antiparasitic that belongs to the milbemycin class of macrocyclic lactones (MLs). It is a semi-synthetic methoxime derivative of the natural compound Nemadectin. Moxidectin's unique structure, including its lipophilic nature and poor affinity for P-glycoproteins, contributes to a sustained residual anti-parasitic activity in the host. This chemical profile allows the compound to maintain therapeutic concentrations for a longer duration compared to many other MLs.

Cydectine's Unique Endectocide Type and Differentiation

Cydectine is recognized for its ability to function as an endectocide, targeting a wide spectrum of parasitic stages, including those that may be less susceptible to other compounds. This dual-action capability, supported by the long-acting formulations used in its Solution for Injection and Oral Gel forms, allows for extended treatment intervals. The efficacy and sustained activity of the active ingredient characterize its role in parasite control. This unique profile and targeted formulation differentiate the Cydectine product line as a specialist agent for comprehensive parasite management.

Regulatory References

  1. [PubChem - NIH]
  2. European Medicines Agency (EMA)
  3. [EMA - Moxidectin Referral]

What side effects are possible with Cydectine?

Possible Side Effects and Safety Information

This section details the officially documented adverse reactions and safety constraints for Cydectine (Moxidectin), based strictly on government regulatory documents.

Adverse Reactions by Frequency and System

Adverse reactions are formally categorized by frequency in regulatory documents:

  • Rare (1 to 10 in 10,000 animals): Reactions include injection site swelling, depression, and ataxia (clumsy motion).
  • Very Rare (less than 1 in 10,000 animals): Reactions include severe neurological disorders such as collapse, convulsion, paralysis, and blindness, as well as hypersensitivity reactions and injection site abscesses.

Transient systemic effects, such as salivation, drowsiness, and weakness, may also occur, particularly with overexposure.

Serious Adverse Reactions and Safety Constraints

Regulatory information highlights several critical safety concerns:

Category Key Safety Statement
Serious Reactions Severe neurological events (e.g., collapse, paralysis) and death have been documented, especially following accidental intravascular injection.
Population Limits Not approved for female dairy cattle 20 months of age or older, including dry cows. Not recommended for calves less than 8 weeks old. Do not use in sick, debilitated, or underweight animals.
Administration Restriction The product must not be given by other routes of administration. It is strictly constrained from use in other animal species (e.g., dogs), where fatal reactions can occur.

Duration and Contextual Safety Notes

Injection site swellings may be immediate or delayed and generally disappear within two weeks. The product is also classified as very toxic to aquatic life, which is an environmental safety consideration outlined in regulatory texts. Specific precautions must be taken to avoid accidental self-injection, and the required slaughter withdrawal period must be observed.

Overdose and Emergency Response

Overdose and When to Seek Help — Official Regulatory Information for Cydectine

This section summarizes official regulatory information regarding overdose presentations and required emergency actions for Cydectine (moxidectin).


Overdose Scope

Feature Official Regulatory Statement
Documented Presentations Symptoms observed in animal studies (with doses up to ten times the therapeutic amount) include transient salivation, depression, drowsiness, and ataxia (incoordination).
Physiological Systems Affected Neurological/Musculoskeletal (depression, drowsiness, ataxia) and Gastrointestinal (transient salivation).
Antidote There is no specific antidote available.

Required Emergency Actions

In the event of accidental human Ingestion of Cydectine, regulatory documents classify the substance as potentially Toxic if swallowed, requiring immediate medical intervention.

Immediately call a POISON CENTER or doctor/physician.

Urgent hospital treatment is likely to be needed. Procedural instructions for accidental ingestion emphasize not inducing vomiting and giving water to rinse the mouth, followed by a small amount of liquid, provided the person is fully awake. If vomiting occurs, ensure the individual is leaned forward or positioned to prevent aspiration.

Summary

The official overdose profile is characterized by transient, non-fatal neurological symptoms observed at high doses in animals. However, accidental human ingestion is treated as a serious hazard requiring urgent medical attention and immediate contact with emergency services or a poison center.

Therapeutic Uses of Cydectine

What Cydectine Treats: Main Uses and Benefits

This medication is used across therapeutic domains involving acute or disruptive parasitic disease patterns. The medication may assist with managing symptoms related to systemic imbalance that present as severe, persistent itching, progressive skin thickening manifestations, and potential visual symptoms associated with Onchocerciasis (River Blindness). The medication may assist with easing the overall symptom burden in conditions characterized by a dual load of internal parasites, such as gastrointestinal nematodes and lungworms, as well as external infestations like mites and lice.


This medication is commonly used to help with conditions presenting with systemic or localized discomfort, which can include poor weight gain, body condition decline, and severe surface irritation. The treatment is relevant in clinical settings involving episodic or fluctuating manifestations due to its role in supporting symptomatic management over a longer timeframe.

“The treatment is relevant in contexts involving heightened systemic burden due to its role in assisting with sustained symptomatic management over a longer timeframe.”

This supports general well-being in programmatic settings by assisting with sustained symptomatic management during periods of potential re-exposure.


Quick Fact: Relief for Parasite-Related Discomfort

Property Description
Main Therapeutic Focus Onchocerciasis (River Blindness)
Symptom Focus Persistent itching, skin damage, reduced body condition
Core Therapeutic Advantage Sustained symptomatic management
Therapeutic Scope Endectocide (Internal and External Parasites)

Eligibility and Restrictions for Use

Eligibility Map: Who can and cannot use Cydectine – Official Regulatory Information

Cydectine (moxidectin) is approved by regulatory authorities for specific patient populations, with several conditional restrictions documented in official labeling.

Contraindications: No formal, absolute contraindications (such as a history of allergy) are explicitly reported in the official prescribing information.

Age and Weight Eligibility Status Criteria
Established Use Patients aged 4 years and older and weighing at least 13 kg (kilograms).
Use Not Established Children younger than 4 years of age or those weighing less than 13 kg (kilograms).

Conditional and Restricted Use

  • Co-infection Risk: Use is strongly cautioned against for patients who are co-infected with Loa loa. Regulatory guidance highlights the potential for serious or fatal neurological complications, and screening is recommended in endemic areas.
  • Physiological Status (Lactation): Use is not recommended for women who are breastfeeding at the time of treatment or during the seven days immediately following administration.
  • Organ Impairment: Eligibility is restricted for patients with severe renal impairment or hepatic impairment, as the drug’s safety profile has not been studied in these specific populations.
  • Repeat Treatment: The safety and efficacy of repeat administration have not been studied and are not currently within the established use profile.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory documents define the interaction profile for Moxidectin (the active ingredient in Cydectine) based on rigorous testing and established restrictions.

Pharmacokinetic Interaction Profile

Official regulatory data indicates a low potential for drug-drug interactions mediated by metabolism or transport. In controlled studies, Moxidectin did not significantly alter the exposure (AUC or Cmax) of the sensitive CYP3A4 substrate Midazolam when co-administered. Furthermore, in vitro data confirms that Moxidectin is not a substrate, inhibitor, or inducer of major CYP enzymes. It is also formally documented as not being a substrate for the efflux transporters P-glycoprotein (P-gp) or BCRP1.

Formal Interaction Restrictions

Restriction Category Substance/Condition Regulatory Requirement
Contraindicated Combination Loa loa co-infection (Loiasis) Must not be used in co-infected patients due to risk of severe or fatal encephalopathy.
Food Interaction High-fat meal Administration is permitted with or without food, as the documented increase in absorption is not deemed clinically relevant by regulatory authorities.
Timing Requirements Other Medications No official regulatory rules mandate time separation for co-administered medicinal products.

Mechanism of Action

The mechanism of Moxidectin is defined by its high-affinity agonism at glutamate-gated chloride channels ( GluCls), molecular targets found exclusively on the nerve and muscle cells of susceptible parasites. This binding locks the channels open, causing a massive influx of chloride ions ( Cl^-) that electrically hyperpolarizes the cells, rendering them unable to generate signals.

This cellular hyperpolarization blocks all functional neuromuscular coordination, shutting down the parasite's systems. The resulting flaccid paralysis immediately halts locomotion and functions such as feeding (paralyzing the pharyngeal pump), which prevents nutrient uptake and leads to a state of sustained functional arrest.

The paralysis extends to the specialized musculature of female nematode uteri, engaging the drug’s anti-fecundity action. By disrupting these necessary muscular contractions, the mechanism inhibits the release of microfilariae, preventing the parasite from propagating.

Dosage and Administration Information

The administration of Cydectine is officially structured around its active ingredient, Moxidectin, which is available in various forms, including oral tablets, subcutaneous solutions, and topical applications. For the primary approved human use, the standardized route of delivery is oral administration.

Official Administration Guidelines

Category Official Instruction
Route of Administration Oral administration (tablet) is used for the main approved human indication.
Standard Dosing Regimen The standard regimen for adults and pediatric patients weighing 30 kg or more is a single oral dose of 8 mg. Dosing for children weighing less than 30 kg is adjusted based on body weight.
Frequency and Timing The medicine is an intermittent, single-dose treatment. Due to its sustained activity, official guidelines state that treatment may only be repeated after a minimum interval of 12 months.
Procedural Condition The oral tablet must be swallowed whole and is to be taken with water. The label does not specify timing relative to food intake.
Population-Specific Rules No specific dose adjustments for older adults are required.

Connection to the overall use protocol: The official use protocol is structured as an intermittent, single therapeutic intervention defined by precise instructions rather than a daily or short-course regimen. This infrequent dosing schedule is consistent with the sustained pharmacological presence observed in the active compound. The requirement to swallow the oral tablet whole and administer it with water ensures proper procedural compliance with established procedural standards.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Cydectine

This section provides an overview of the types of scientific research that have been conducted on Moxidectin, describing what the studies examined and what remains uncertain. This summary reflects group patterns observed in the studies and does not determine whether an individual will respond similarly.

Evidence for Use in Onchocerciasis (River Blindness)

Research for Onchocerciasis (River Blindness) was studied in large, organized Phase 2 and Phase 3 Randomized Controlled Trials. These studies were conducted on populations included based on confirmed signs of infection with the parasite Onchocerca volvulus.

Researchers examined specific laboratory measurements, primarily focusing on the Microfilarial Density (the count of larvae in the skin) and monitoring the Proportion of participants with undetectable microfilariae. The key findings submitted to regulatory bodies describe patterns observed in which studies examined whether a single administration was related to the measurements of microfilarial density in the skin. These reported outcomes were tracked over defined time intervals, extending up to 12 months post-treatment.

Evidence for Use in Lymphatic Filariasis

Research on Lymphatic Filariasis was evaluated in Phase 2 and Phase 3 randomized clinical trials. These studies often compared combination regimens against existing standard therapies.

Trials report that administration, typically used as a component of a combination regimen with other compounds, was followed by researchers monitoring outcomes exploring the elimination of microfilariage (larvae in the blood) over observed time periods, such as 12 and 24 months. Evidence quality appears to be moderate, and research highlights changes measured during the study period to inform ongoing global public health strategies.

Evidence in Special Populations and Research Gaps

Data for children under the age of 12 remain insufficient. Similarly, data for older adults or those with other concurrent health conditions remain limited, as results apply only to the relatively specific populations included in the original trials. The evidence base does not contain the results of long-term studies that monitored the outcomes after multiple or repeat administrations of the medication. The research describes action against the larval stage (microfilariae) but does not include data on the medication's effect on the adult parasitic worms (macrofilaricidal activity).

Frequently Asked Questions (FAQ)

Common questions about Cydectine (FAQ)


Q: Can Cydectine be taken with alcohol?

Regulatory documents do not contain specific information or restrictions regarding the co-administration of Cydectine with alcohol. Official product information only states that no rules mandate time separation for co-administered medicinal products in general.


Q: Is Cydectine safe for older adults to use?

Official US Prescribing Information indicates that no specific dosage adjustment is required for older adults. However, studies defining the safety and use of the medicine in this population are described as limited. The final decision regarding use is based on a healthcare professional's assessment of a patient's specific health profile.


Q: Can Cydectine be crushed or split?

Official administration instructions for the oral tablet state that it must be swallowed whole. Dividing, crushing, or splitting the tablet is not part of the standard use protocol.


Q: Is Cydectine safe to use if I have kidney problems?

Official eligibility information states that the drug's safety profile has not been studied in patients with severe renal (kidney) impairment. The need for use in patients with existing kidney issues is determined by a healthcare professional.


Q: Are there any special warnings for people with liver conditions taking Cydectine?

Official regulatory guidance indicates that the drug's safety profile has not been studied in patients with hepatic (liver) impairment. The use of the medicine in patients with a pre-existing liver condition is decided upon by a healthcare professional.


Q: Is Cydectine the same as ivermectin?

No, Cydectine's active ingredient, Moxidectin, is a distinct compound. It is classified as a semi-synthetic derivative of nemadectin and belongs to the milbemycin class of macrocyclic lactones. It was compared to ivermectin in clinical trials.


Q: How quickly can I expect Cydectine to start working?

Regulatory information notes that reactions related to the death of the parasite, such as flu-like symptoms (sometimes called the Mazzotti reaction), may occur most commonly during the first week after treatment. The appearance of these reactions is evidence that the drug's action has begun.


Q: Can Cydectine be used for any other conditions besides the main ones?

Cydectine Tablets are formally indicated only for the treatment of onchocerciasis (River Blindness) due to the parasite Onchocerca volvulus in approved patient populations. It is not indicated for other conditions.


Q: What happens if I miss a dose of Cydectine?

Cydectine is intended as a single, intermittent treatment. Official regulatory instructions address this scenario by stating that a missed dose should be administered as soon as possible.


Q: Is it normal to feel tired after taking Cydectine?

Official prescribing information lists unusual tiredness or weakness as reported side effects that occurred during clinical studies. These effects may be transient.


Q: Does Cydectine have a black box warning?

The official US prescribing information does not contain a Boxed Warning (Black Box Warning), which is a specific type of regulatory caution. The most serious documented warning concerns the potential for severe neurological complications in patients co-infected with Loa loa.


Q: Where does the active ingredient in Cydectine come from?

The active ingredient, Moxidectin, is a semi-synthetic derivative of a naturally occurring compound called nemadectin. This compound is derived from the fermentation of the Streptomyces cyaneogriseus microorganism.


Q: If I have allergies, can I still take Cydectine?

Official safety information includes hypersensitivity reactions as a reported possibility. A healthcare professional determines eligibility for use based on a patient's complete history, including known allergies.


Q: Is Cydectine considered a strong or potent medicine?

Scientific descriptions in authoritative sources classify the active ingredient, Moxidectin, as a potent, broad-spectrum antiparasitic, which reflects its intended high level of activity against parasites.


Q: What are the most commonly reported side effects of Cydectine?

Based on clinical trial data, some of the most frequently reported reactions in studies include itching (pruritus), headache, fast heartbeat (tachycardia), and skin rash. The frequency of these effects varied among participants.


Q: What should I do if I feel worse after taking Cydectine?

Official patient guidance describes the need for medical assessment if signs of a serious reaction occur or if symptoms worsen after administration.


Q: Are there different strengths or formulations of Cydectine available?

The human formulation approved by the FDA is available as a 2 mg oral tablet. In broader pharmacological descriptions, the active ingredient Moxidectin is also available in forms such as a solution for injection and oral gel, which are often used in veterinary medicine.


Q: Is Cydectine used in veterinary medicine?

Yes, the active ingredient Moxidectin is widely used and approved in many countries as a broad-spectrum anti-parasitic agent, or anthelmintic, in veterinary medicine for livestock and companion animals.


Q: Does Cydectine affect birth control pills?

Official interaction studies indicate a low potential for the active ingredient Moxidectin to be a substrate, inhibitor, or inducer of major metabolic enzymes (CYP enzymes). This finding is used by healthcare professionals when assessing potential interactions with other products, such as hormonal contraceptives.


Q: Why do some people experience mild dizziness after Cydectine?

Dizziness is listed as a commonly reported side effect. This may be linked to orthostatic hypotension, which means low blood pressure when changing positions, such as when getting up from sitting or lying down.


Q: Is Cydectine a Schedule drug?

Cydectine is a prescription medicine approved by the FDA for the treatment of onchocerciasis. It is not classified as a controlled substance (Schedule drug) by the US Drug Enforcement Administration (DEA).


Q: Does Cydectine cause drowsiness?

Yes, official regulatory documents list transient systemic effects, including drowsiness, as possible adverse reactions that may be experienced with the use of the medicine.

How should Cydectine be stored and disposed of?

How to Store and Dispose of Cydectine

Official regulatory information for Cydectine (Moxidectin) defines specific storage, stability, and disposal requirements necessary to maintain product integrity and ensure environmental safety.

Storage and Handling Requirements

The product must be stored below a specified maximum temperature, typically 25 C or 30 C, and protected from light. To achieve this, the product must be kept in its original outer carton with the container tightly closed. Instructions often prohibit storing the product above the maximum temperature and may advise against freezing. For stability, the drug has a defined shelf-life after first opening the container, which must be strictly followed.

Disposal Requirements

Due to Moxidectin’s toxicity to aquatic life, disposal is subject to environmental constraints. Unused or expired product and any waste material must be disposed of according to local regulatory requirements. It is officially stated that the product must not contaminate watercourses.

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

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