Selarid

Description

Selarid® (selamectin) Topical Parasiticide is presented as a colorless to yellow, ready-to-use solution contained in single-dose applicators, designed for topical (dermal) administration in dogs six weeks of age and older, and cats eight weeks of age and older. Each applicator is formulated to deliver a minimum dosage of 2.7 mg/lb (6 mg/kg) of body weight of selamectin. The chemical structure of selamectin is defined as (5Z,25S)-25-cyclohexyl-4'-de(2,6-dideoxy-3-methyl-α-L-arabino-hexopyranosyl)-5-demethoxy-25-de(1-methylpropyl)-22,23-dihydro-5-hydroxyiminoavermectin A1a.

Uses and Indications

This drug is indicated for use in dogs six weeks of age or older and in cats eight weeks of age or older.

In dogs, the drug is indicated for the prevention and control of flea infestations caused by Ctenocephalides felis, prevention of heartworm disease due to Dirofilaria immitis, treatment and control of ear mite infestations from Otodectes cynotis, treatment and control of sarcoptic mange caused by Sarcoptes scabiei, and control of tick infestations due to Dermacentor variabilis.

In cats, the drug is indicated for the prevention and control of flea infestations caused by Ctenocephalides felis, prevention of heartworm disease due to Dirofilaria immitis, treatment and control of ear mite infestations from Otodectes cynotis, treatment and control of roundworm infections caused by Toxocara cati, and treatment and control of intestinal hookworm infections due to Ancylostoma tubaeforme.

The drug should be administered topically once a month to provide protection against fleas and heartworm disease, as well as for the treatment and control of hookworms, roundworms, and ear mites.

Dosage and Administration

The recommended minimum dose of Selarid is 2.7 mg selamectin per pound (6 mg/kg) of body weight. The entire contents of a single dose applicator should be administered topically. For dogs weighing over 130 pounds, two applicators may be used in combination.

For cats, the dosing is as follows:

• For cats weighing up to 5 lbs, administer 15 mg (Mauve package), which corresponds to 0.25 mL.

• For cats weighing 5.1-15 lbs, administer 45 mg (Blue package), which corresponds to 0.75 mL.

• For cats weighing 15.1-22 lbs, administer 60 mg (Taupe package), which corresponds to 1.0 mL.

• For cats over 22 lbs, use the appropriate combination of applicators to achieve the required dose.

For dogs, the dosing is as follows:

• For dogs weighing up to 5 lbs, administer 15 mg (Mauve package), which corresponds to 0.25 mL.

• For dogs weighing 5.1-10 lbs, administer 30 mg (Purple package), which corresponds to 0.25 mL.

• For dogs weighing 10.1-20 lbs, administer 60 mg (Brown package), which corresponds to 0.5 mL.

• For dogs weighing 20.1-40 lbs, administer 120 mg (Red package), which corresponds to 1.0 mL.

• For dogs weighing 40.1-85 lbs, administer 240 mg (Teal package), which corresponds to 2.0 mL.

• For dogs weighing 85.1-130 lbs, administer 360 mg (Plum package), which corresponds to 3.0 mL.

• For dogs over 130 lbs, use the appropriate combination of applicators to achieve the required dose.

Selarid is recommended for use in dogs 6 weeks of age and older and in cats 8 weeks of age and older. Prior to the first use, a veterinarian or veterinary technician should demonstrate or instruct the pet owner on the appropriate technique for applying Selarid topically to dogs and cats.

To administer the product, part the hair on the back of the animal at the base of the neck in front of the shoulder blades until the skin is visible. Place the tip of the applicator on the skin and squeeze the applicator 3 or 4 times to empty its entire contents directly onto the skin in one spot.

Contraindications

Use of this product is contraindicated in sick, debilitated, or underweight animals.

Application is not recommended on broken skin or when the haircoat is wet. The product should not be massaged into the skin, and contact between the product and fingers should be avoided. In the event of human ingestion, immediate medical attention should be sought. This product must be kept out of reach of children and is not intended for human use.

Warnings and Precautions

User safety is paramount when handling Selarid. This product is strictly not for human use and must be kept out of reach of children. In humans, Selarid may cause irritation to the skin and eyes. Reports of adverse reactions, including hives, itching, and skin redness, have been documented. Individuals with a known hypersensitivity to Selarid should exercise caution or consult a healthcare professional prior to use.

Selarid contains isopropyl alcohol and the preservative butylated hydroxytoluene (BHT), which may contribute to these reactions. It is essential to wash hands thoroughly after use and to immediately cleanse any product that comes into contact with the skin using soap and water.

In the event of eye contact, it is critical to flush the eyes copiously with water. If contact lenses are being worn, they should be removed after rinsing the eyes initially, and the flushing should continue for 5 to 10 minutes. Medical attention should be sought promptly following any eye exposure. Should ingestion occur, immediate contact with a physician is necessary.

For comprehensive occupational safety information, the safety data sheet (SDS) should be consulted. The SDS can be obtained by contacting 1-866-591-5777 or visiting www.norbrook.com.

Additionally, Selarid is flammable; therefore, it must be kept away from heat sources, sparks, open flames, or any other potential ignition sources to ensure safe handling and use.

Side Effects

Adverse reactions associated with the use of the product have been observed in both pre-approval clinical trials and post-approval experiences.

In pre-approval clinical trials involving 691 treated cats, transient localized alopecia, with or without inflammation at or near the site of application, was noted in approximately 1% of subjects. Other adverse reactions were reported in less than 0.5% of 1,743 treated cats and dogs, including vomiting, loose stool or diarrhea (with or without blood), anorexia, lethargy, salivation, tachypnea, and muscle tremors.

Post-approval experience data from 2021 indicate a range of adverse events reported for dogs, listed in decreasing order of frequency. The most commonly reported reactions include lethargy, vomiting, diarrhea, anorexia, and generalized pruritus. Less frequently reported events include seizures, application site reactions (such as alopecia, lesions, erythema, pruritus, and inflammation), tremors, ataxia, dermatitis, and, in rare cases, death.

For cats, the adverse events reported in decreasing order of frequency include application site reactions (which encompass alopecia, lesions, erythema, pruritus, inflammation, vesicles, blisters, and excoriations), lethargy, anorexia, vomiting, and death. Other reported reactions include generalized pruritus, diarrhea, ataxia, fever, generalized alopecia, tremors, hypersalivation, dermatitis, and seizures.

Warnings have been issued regarding potential reactions in humans, including hives, itching, and skin redness. Individuals with known hypersensitivity to Selarid are advised to use the product with caution or consult a healthcare professional prior to use.

Drug Interactions

Selamectin, the active ingredient in Selarid, is a macrocyclic lactone compound. The efficacy of macrocyclic lactones, including Selarid, may be compromised if administered to dogs more than two months after exposure to infective (L3) Dirofilaria immitis larvae. Therefore, it is crucial to ensure timely administration to maintain optimal effectiveness.

For animals with an unknown heartworm history, it is important to conduct heartworm testing prior to initiating treatment with Selarid. Even if the initial test result is negative, there is a possibility that the animal may harbor pre-patent infections at the time treatment begins. To confirm the negative heartworm status, retesting should be performed 3 to 4 months after the initiation of Selarid.

In cats over six months of age, veterinarians may consider testing for existing heartworm infections before starting treatment with Selarid, based on clinical judgment.

Selarid has demonstrated a favorable safety profile and can be used concurrently with other commonly utilized veterinary products, including vaccines, anthelmintics, antiparasitics, antibiotics, steroids, collars, shampoos, and dips, without significant interactions.

Packaging & NDC

The table below lists each NDC Code for Selarid (selamectin) veterinary formulations. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

Selarid (selamectin) is indicated for use in dogs six weeks of age and older and in cats eight weeks of age and older. The recommended minimum dosage is 2.7 mg selamectin per pound (6 mg/kg) of body weight.

In dogs, Selarid is effective for the prevention and control of flea infestations, prevention of heartworm disease, treatment and control of ear mite infestations, treatment and control of sarcoptic mange, and control of tick infestations. For cats, it is indicated for the prevention and control of flea infestations, prevention of heartworm disease, treatment and control of ear mite infestations, and treatment and control of roundworm and intestinal hookworm infections.

Prior to the first use, a veterinarian or veterinary technician should instruct pet owners on the appropriate technique for the topical application of Selarid. Selarid should not be administered to dogs younger than six weeks of age or cats younger than eight weeks of age.

In safety studies, selamectin was applied at doses of 1, 3, 5, and 10 times the recommended dose to six-week-old puppies and kittens without any observed adverse reactions. It is important to note that Selarid is not effective against adult Dirofilaria immitis and is not recommended for use in sick, debilitated, or underweight animals.

Geriatric Use

Elderly patients may exhibit increased sensitivity to side effects when treated with Selarid. Therefore, caution is advised when administering this medication to geriatric animals. Selarid is recommended for use in dogs six weeks of age or older and in cats eight weeks of age and older. However, it should not be used in sick, debilitated, or underweight animals, which may include some elderly patients.

Prior to the administration of Selarid, it is essential for veterinarians to test dogs for existing heartworm infections. For cats over six months of age, testing may also be considered at the veterinarian's discretion to determine the presence of heartworm infections before initiating treatment with Selarid. It is important to note that Selarid is not effective against adult Dirofilaria immitis and does not facilitate microfilariae clearance.

In safety studies, selamectin solution was administered at various dosages (1, 3, 5, and 10 times the recommended dose) to six-week-old puppies, with no adverse reactions observed. Selamectin solution has been tested for safety in over 100 different pure and mixed breeds of healthy dogs and over 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females, breeding males and females, puppies six weeks of age and older, and kittens eight weeks of age and older.

However, caution is warranted due to a reported incident involving a kitten estimated to be 5-6 weeks old (0.3 kg) that died 8.5 hours after receiving a single treatment of selamectin solution at the recommended dosage. The kitten exhibited clinical signs such as muscle spasms, salivation, and neurological symptoms, and was noted to be malnourished and underweight, with an unknown medical history.

In a pre-clinical study involving ivermectin-sensitive collies, selamectin was dosed orally without adverse reactions; however, one collie experienced ataxia after receiving 5 mg/kg orally but did not show any further adverse reactions after subsequent doses. Given these findings, it is imperative that geriatric patients receiving Selarid be closely monitored for any potential adverse effects.

Pregnancy

Selamectin solution has been evaluated for safety in over 100 different pure and mixed breeds of healthy dogs and over 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females. The data suggest that selamectin does not pose significant risks to pregnant patients when used as directed. However, it is important to note that Selarid is not effective against adult Dirofilaria immitis, and while treatment may reduce the number of circulating microfilariae, it does not facilitate microfilariae clearance.

In a specific case, a kitten estimated to be 5-6 weeks old (0.3 kg) died 8 ½ hours after receiving a single treatment of selamectin solution at the recommended dosage. The kitten exhibited clinical signs such as muscle spasms, salivation, and neurological symptoms. It is crucial to consider that this kitten was a stray with an unknown history and was malnourished and underweight, which may have contributed to the adverse outcome.

For dogs, it is recommended that they be tested for existing heartworm infections prior to the administration of Selarid. If a dog is found to be infected, the veterinarian may decide to treat the dog to remove adult heartworms before initiating treatment with Selarid. Similarly, cats over 6 months of age may be tested for heartworm infections before starting Selarid treatment. Cats that are already infected with adult heartworms can safely receive Selarid monthly to prevent further infections.

Lactation

Selamectin solution has been tested for safety in over 100 different pure and mixed breeds of healthy dogs and over 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females. There is no specific data available regarding the excretion of selamectin in human breast milk or its effects on breastfed infants.

Lactating mothers should consult with their healthcare provider to assess the risks and benefits of using selamectin while breastfeeding. It is important to note that Selarid is not effective against adult Dirofilaria immitis, and while treatment may reduce the number of circulating microfilariae, it does not clear them. Therefore, lactating mothers with pets that may require treatment should discuss the implications with their veterinarian, especially if the pets are pregnant or lactating.

Renal Impairment

Patients with renal impairment have not been specifically addressed in the available prescribing information. There are no dosage adjustments, special monitoring requirements, or safety considerations outlined for individuals with reduced kidney function. Healthcare professionals should exercise caution and consider the lack of data when prescribing to this patient population.

Hepatic Impairment

Patients with hepatic impairment have not been specifically studied in clinical trials for this medication. Consequently, there is no available information regarding dosage adjustments, special monitoring requirements, or precautions for individuals with compromised liver function. It is recommended that healthcare providers exercise caution when prescribing this medication to patients with hepatic impairment, given the lack of data on its safety and efficacy in this population. Regular monitoring of liver function may be warranted based on clinical judgment.

Overdosage

In the event of an overdose, it is imperative to seek immediate medical attention. Healthcare professionals should be alerted to any instances of ingestion by a human, as prompt intervention is crucial for patient safety.

Upon recognition of an overdose, the following steps are recommended:

1. Immediate Action: Contact a physician or poison control center without delay. This ensures that the patient receives appropriate guidance and management based on the specific circumstances of the overdose.

2. Monitoring Symptoms: Healthcare providers should be vigilant for potential symptoms associated with the overdose. While specific symptoms are not detailed in the provided information, it is essential to assess the patient for any signs of distress or adverse reactions.

3. Management Procedures: The management of an overdose may involve supportive care and symptomatic treatment. The healthcare team should be prepared to implement necessary interventions based on the patient's clinical presentation and the substance involved.

In summary, the key to managing an overdose lies in immediate medical consultation and thorough monitoring of the patient’s condition.

Nonclinical Toxicology

Animal pharmacology and toxicology studies indicate that the product should not be administered to sick, debilitated, or underweight animals. There is no available information regarding teratogenic or non-teratogenic effects. Additionally, no data has been provided concerning nonclinical toxicology.

Postmarketing Experience

Adverse events reported in the postmarketing experience for dogs include lethargy, vomiting, diarrhea, anorexia, generalized pruritus, seizures, application site reactions (such as alopecia, lesions, erythema, pruritus, and inflammation), tremors, ataxia, death, and dermatitis, listed in decreasing order of reporting frequency.

For cats, the reported adverse events, also in decreasing order of frequency, include application site reactions (which encompass alopecia, lesions, erythema, pruritus, inflammation, vesicles, blisters, and excoriations), lethargy, anorexia, vomiting, death, generalized pruritus, diarrhea, ataxia, fever, generalized alopecia, tremors, hypersalivation, dermatitis, and seizures.

Following treatment with selamectin solution, transient localized alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats. Other signs reported in less than 0.5% of 1,743 treated cats and dogs included vomiting, loose stool or diarrhea (with or without blood), anorexia, lethargy, salivation, tachypnea, and muscle tremors.

Severe application site reactions, such as blisters, scabbing, and infection, have been documented in cats. Additionally, cases of death have been reported in both dogs and cats.

Patient Counseling

Healthcare providers should advise patients that Selarid is a topical parasiticide intended for use on dogs six weeks of age and older and cats eight weeks of age and older. It is effective in killing adult fleas, preventing flea eggs from hatching, preventing heartworm disease, and protecting pets against other parasites.

Patients should be informed that Selarid should not be used in sick, debilitated, or underweight animals. Prior to administering Selarid, dogs should be tested for heartworm disease. If a dog tests positive for adult heartworms, the veterinarian can recommend appropriate treatment, as dogs infected with adult heartworms can safely receive Selarid. For cats older than six months, the veterinarian may also decide to test for heartworm disease before prescribing Selarid, which can be given to cats infected with adult heartworms to prevent further infections.

Instruct patients to apply Selarid monthly and to immediately apply a missed dose if they forget, while also notifying their veterinarian. Patients should contact their veterinarian if they administer more than the prescribed amount of Selarid.

When applying Selarid, patients should be guided to remove the applicator from the outer pouch using scissors or by tearing back at the nick. They should hold the applicator upright, tap the narrow part to ensure the contents remain within, and twist or snap back the tip. Patients should part the hair on the back of the animal at the base of the neck until the skin is visible, apply the tip of the applicator directly to the skin, and squeeze firmly 3-4 times in one spot until empty, avoiding contact between Selarid and their fingers. It is important to instruct patients not to massage Selarid into the skin, apply it when the haircoat is wet, or apply it to broken skin, as Selarid contains alcohol.

Patients may observe temporary effects such as stiff hair, clumping, hair discoloration, or a slight powdery residue at the application site, which do not affect the safety or effectiveness of the product. Bathing or shampooing the dog two or more hours after treatment or the cat 24 hours after treatment will not reduce Selarid's effectiveness against fleas or heartworm. Patients should avoid contact with the application site when wet and may hold or play with their pet once the area is dry.

Patients should be made aware that while Selarid kills adult fleas and prevents flea eggs from hatching, they may occasionally see a few fleas on treated pets, as more than 98% of adult fleas are killed within 36 hours. Immature flea stages, known as pupae, may still be present in the environment and can emerge as adult fleas. Selarid controls tick infestations only for the American Dog Tick (Dermacentor variabilis) and does not affect other common tick species.

Patients should be informed of potential side effects following the use of Selarid. In dogs, these may include sluggishness, vomiting, diarrhea (with or without blood), decreased appetite, generalized itching, seizures, hair loss or skin redness at the application site, trembling, incoordination, skin inflammation, drooling, and rapid breathing, with some cases resulting in death. In cats, side effects may include hair loss at the application site (with or without redness), sluggishness, decreased appetite, vomiting, generalized itching, diarrhea (with or without blood), incoordination, fever, trembling, drooling, skin inflammation, and seizures, with severe reactions such as blisters, scabbing, and infection reported, and some cases resulting in death.

Selarid is not intended for human use and should be kept out of reach of children. In humans, Selarid may cause skin and eye irritation, with reactions such as hives, itching, and skin redness reported. Individuals with known hypersensitivity to Selarid should use the product with caution or consult a healthcare professional. Patients should wash their hands after use and immediately wash off any product that comes into contact with skin using soap and water. In the event of human ingestion, patients should be advised to contact a doctor immediately.

Storage and Handling

The product is supplied in various package configurations, with specific NDC numbers available for identification. It is essential to store the product in a controlled environment, maintaining a temperature below 86°F (30°C) to ensure its stability and efficacy. Proper container requirements should be adhered to, and any special handling needs must be followed to preserve the integrity of the product.

Additional Clinical Information

Selarid is administered topically, with specific dosing guidelines based on the target species and condition being treated. For dogs, the entire contents of a single dose applicator should be used, or two applicators for those weighing over 130 pounds. To prevent and control flea infestations, Selarid should be applied monthly throughout the flea season, starting one month prior to flea activity. Monthly administration is also required for heartworm prevention and tick control. For ear mite infestations and sarcoptic mange, a single topical dose is sufficient. In cats, a single topical dose is recommended for the treatment and control of intestinal hookworm and roundworm infections.

Clinicians should counsel patients on proper application techniques, including washing hands after use and avoiding contact with the product on skin or hair. In the event of eye contact, thorough rinsing is advised, and ingestion by humans necessitates immediate medical attention. Temporary effects such as stiff hair, clumping, discoloration, or a powdery residue may occur at the treatment site but do not compromise the product's safety or efficacy. Postmarketing experience has revealed various adverse events, with lethargy, vomiting, and application site reactions being the most frequently reported in dogs, while cats have shown similar reactions along with additional symptoms such as fever and hypersalivation.

Drug Information (PDF)

This document includes the full labeling information for Selarid, as submitted by MWI/VetOne for veterinary use. It may include dosage by species, withdrawal periods, and administration instructions.

View veterinary label (PDF)